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1060 lines
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HTML
1060 lines
96 KiB
HTML
<!DOCTYPE html>
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<!--[if IE]><![endif]-->
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<html>
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<head>
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<meta charset="utf-8">
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<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
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<title>教程 | React</title>
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<meta name="viewport" content="width=device-width">
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<meta property="og:title" content="教程 | React">
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<meta property="og:type" content="website">
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<meta property="og:url" content="https://facebook.github.io/react/docs/tutorial.zh-CN.html">
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<meta property="og:image" content="https://facebook.github.io/react/img/logo_og.png">
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<meta property="og:description" content="A JavaScript library for building user interfaces">
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<link rel="shortcut icon" href="/react/favicon.ico">
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<link rel="alternate" type="application/rss+xml" title="React" href="https://facebook.github.io/react/feed.xml">
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<link rel="stylesheet" href="/react/css/syntax.css">
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<link rel="stylesheet" href="/react/css/codemirror.css">
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<link rel="stylesheet" href="/react/css/react.css">
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<script src="//use.typekit.net/vqa1hcx.js"></script>
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<script>try{Typekit.load();}catch(e){}</script>
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<!--[if lte IE 8]>
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<script src="/react/js/html5shiv.min.js"></script>
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<script src="/react/js/es5-sham.min.js"></script>
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<![endif]-->
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<script src="/react/js/codemirror.js"></script>
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<script src="/react/js/javascript.js"></script>
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<script src="/react/js/react.js"></script>
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<script src="/react/js/react-dom.js"></script>
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<script src="/react/js/babel-browser.min.js"></script>
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<script src="/react/js/live_editor.js"></script>
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</head>
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<body>
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<div class="container">
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<div class="nav-main">
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<div class="wrap">
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<a class="nav-home" href="/react/index.html">
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<img class="nav-logo" src="/react/img/logo.svg" width="36" height="36">
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React
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</a>
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<ul class="nav-site nav-site-internal">
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<li><a href="/react/docs/getting-started.html" class="active">Docs</a></li>
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<li><a href="/react/support.html">Support</a></li>
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<li><a href="/react/downloads.html">Download</a></li>
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<li><a href="/react/blog/">Blog</a></li>
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</ul>
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<ul class="nav-site nav-site-external">
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<li><a href="https://github.com/facebook/react">GitHub</a></li>
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<li><a href="https://facebook.github.io/react-native/">React Native</a></li>
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</ul>
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</div>
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</div>
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<section class="content wrap documentationContent">
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<div class="nav-docs">
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<!-- Docs Nav -->
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<div class="nav-docs-section">
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<h3>Quick Start</h3>
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<ul>
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<li>
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<a href="/react/docs/getting-started.html">Getting Started</a>
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</li>
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<li>
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<a href="/react/docs/tutorial.html">Tutorial</a>
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</li>
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<li>
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<a href="/react/docs/thinking-in-react.html">Thinking in React</a>
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</li>
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</ul>
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</div>
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<div class="nav-docs-section">
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<h3>Community Resources</h3>
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<ul>
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<li>
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<a href="/react/docs/conferences.html">Conferences</a>
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</li>
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<li>
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<a href="/react/docs/videos.html">Videos</a>
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</li>
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<li>
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<a href="/react/docs/complementary-tools.html">Complementary Tools</a>
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</li>
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<li>
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<a href="/react/docs/examples.html">Examples</a>
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</li>
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</ul>
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</div>
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<div class="nav-docs-section">
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<h3>Guides</h3>
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<ul>
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<li>
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<a href="/react/docs/why-react.html">Why React?</a>
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</li>
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<li>
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<a href="/react/docs/displaying-data.html">Displaying Data</a>
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<ul>
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<li>
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<a href="/react/docs/jsx-in-depth.html">JSX in Depth</a>
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</li>
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<li>
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<a href="/react/docs/jsx-spread.html">JSX Spread Attributes</a>
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</li>
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<li>
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<a href="/react/docs/jsx-gotchas.html">JSX Gotchas</a>
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</li>
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</ul>
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</li>
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<li>
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<a href="/react/docs/interactivity-and-dynamic-uis.html">Interactivity and Dynamic UIs</a>
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</li>
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<li>
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<a href="/react/docs/multiple-components.html">Multiple Components</a>
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</li>
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<li>
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<a href="/react/docs/reusable-components.html">Reusable Components</a>
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</li>
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<li>
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<a href="/react/docs/transferring-props.html">Transferring Props</a>
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</li>
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<li>
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<a href="/react/docs/forms.html">Forms</a>
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</li>
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<li>
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<a href="/react/docs/working-with-the-browser.html">Working With the Browser</a>
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<ul>
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<li>
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<a href="/react/docs/more-about-refs.html">Refs to Components</a>
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</li>
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</ul>
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</li>
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<li>
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<a href="/react/docs/tooling-integration.html">Tooling Integration</a>
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</li>
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<li>
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<a href="/react/docs/addons.html">Add-Ons</a>
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<ul>
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<li>
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<a href="/react/docs/animation.html">Animation</a>
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</li>
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<li>
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<a href="/react/docs/two-way-binding-helpers.html">Two-Way Binding Helpers</a>
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</li>
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<li>
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<a href="/react/docs/test-utils.html">Test Utilities</a>
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</li>
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<li>
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<a href="/react/docs/clone-with-props.html">Cloning Elements</a>
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</li>
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<li>
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<a href="/react/docs/create-fragment.html">Keyed Fragments</a>
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</li>
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<li>
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<a href="/react/docs/update.html">Immutability Helpers</a>
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</li>
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<li>
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<a href="/react/docs/pure-render-mixin.html">PureRenderMixin</a>
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</li>
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<li>
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<a href="/react/docs/perf.html">Performance Tools</a>
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</li>
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<li>
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<a href="/react/docs/shallow-compare.html">Shallow Compare</a>
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</li>
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</ul>
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</li>
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<li>
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<a href="/react/docs/advanced-performance.html">Advanced Performance</a>
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</li>
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<li>
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<a href="/react/docs/context.html">Context</a>
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</li>
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</ul>
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</div>
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<div class="nav-docs-section">
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<h3>Reference</h3>
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<ul>
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<li>
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<a href="/react/docs/top-level-api.html">Top-Level API</a>
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</li>
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<li>
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<a href="/react/docs/component-api.html">Component API</a>
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</li>
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<li>
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<a href="/react/docs/component-specs.html">Component Specs and Lifecycle</a>
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</li>
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<li>
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<a href="/react/docs/tags-and-attributes.html">Supported Tags and Attributes</a>
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</li>
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<li>
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<a href="/react/docs/events.html">Event System</a>
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</li>
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<li>
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||
<a href="/react/docs/dom-differences.html">DOM Differences</a>
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|
||
</li>
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<li>
|
||
<a href="/react/docs/special-non-dom-attributes.html">Special Non-DOM Attributes</a>
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</li>
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<li>
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||
<a href="/react/docs/reconciliation.html">Reconciliation</a>
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||
|
||
</li>
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<li>
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<a href="/react/docs/webcomponents.html">Web Components</a>
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</li>
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<li>
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<a href="/react/docs/glossary.html">React (Virtual) DOM Terminology</a>
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</li>
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</ul>
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</div>
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<div class="nav-docs-section">
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||
<h3>Flux</h3>
|
||
<ul>
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<li>
|
||
<a href="https://facebook.github.io/flux/docs/overview.html">Flux Overview</a>
|
||
|
||
</li>
|
||
|
||
<li>
|
||
<a href="https://facebook.github.io/flux/docs/todo-list.html">Flux TodoMVC Tutorial</a>
|
||
|
||
</li>
|
||
|
||
</ul>
|
||
</div>
|
||
|
||
|
||
<!-- Tips Nav -->
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||
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||
<div class="nav-docs-section">
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||
<h3>Tips</h3>
|
||
<ul>
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||
|
||
<li>
|
||
<a href="/react/tips/introduction.html">Introduction</a>
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||
</li>
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||
|
||
<li>
|
||
<a href="/react/tips/inline-styles.html">Inline Styles</a>
|
||
</li>
|
||
|
||
<li>
|
||
<a href="/react/tips/if-else-in-JSX.html">If-Else in JSX</a>
|
||
</li>
|
||
|
||
<li>
|
||
<a href="/react/tips/self-closing-tag.html">Self-Closing Tag</a>
|
||
</li>
|
||
|
||
<li>
|
||
<a href="/react/tips/maximum-number-of-jsx-root-nodes.html">Maximum Number of JSX Root Nodes</a>
|
||
</li>
|
||
|
||
<li>
|
||
<a href="/react/tips/style-props-value-px.html">Shorthand for Specifying Pixel Values in style props</a>
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||
</li>
|
||
|
||
<li>
|
||
<a href="/react/tips/children-props-type.html">Type of the Children props</a>
|
||
</li>
|
||
|
||
<li>
|
||
<a href="/react/tips/controlled-input-null-value.html">Value of null for Controlled Input</a>
|
||
</li>
|
||
|
||
<li>
|
||
<a href="/react/tips/componentWillReceiveProps-not-triggered-after-mounting.html">componentWillReceiveProps Not Triggered After Mounting</a>
|
||
</li>
|
||
|
||
<li>
|
||
<a href="/react/tips/props-in-getInitialState-as-anti-pattern.html">Props in getInitialState Is an Anti-Pattern</a>
|
||
</li>
|
||
|
||
<li>
|
||
<a href="/react/tips/dom-event-listeners.html">DOM Event Listeners in a Component</a>
|
||
</li>
|
||
|
||
<li>
|
||
<a href="/react/tips/initial-ajax.html">Load Initial Data via AJAX</a>
|
||
</li>
|
||
|
||
<li>
|
||
<a href="/react/tips/false-in-jsx.html">False in JSX</a>
|
||
</li>
|
||
|
||
<li>
|
||
<a href="/react/tips/communicate-between-components.html">Communicate Between Components</a>
|
||
</li>
|
||
|
||
<li>
|
||
<a href="/react/tips/expose-component-functions.html">Expose Component Functions</a>
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||
</li>
|
||
|
||
<li>
|
||
<a href="/react/tips/children-undefined.html">this.props.children undefined</a>
|
||
</li>
|
||
|
||
<li>
|
||
<a href="/react/tips/use-react-with-other-libraries.html">Use React with Other Libraries</a>
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||
</li>
|
||
|
||
<li>
|
||
<a href="/react/tips/dangerously-set-inner-html.html">Dangerously Set innerHTML</a>
|
||
</li>
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||
|
||
</ul>
|
||
</div>
|
||
|
||
</div>
|
||
|
||
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||
<div class="inner-content">
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||
<h1>
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教程
|
||
<a class="edit-page-link" href="https://github.com/facebook/react/tree/master/docs/docs/tutorial.zh-CN.md" target="_blank">Edit on GitHub</a>
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||
</h1>
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||
<div class="subHeader"></div>
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||
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<p>我们将建立一个你可以放进博客的简单却真实的评论框，一个 Disqus、LiveFyre 或 Facebook comments 提供的实时评论的基础版本。</p>
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<p>我们将提供：</p>
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<ul>
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<li>一个所有评论的视图</li>
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<li>一个用于提交评论的表单</li>
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||
<li>为你提供制定后台的挂钩(Hooks)</li>
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||
</ul>
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||
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||
<p>同时也会有一些简洁的功能：</p>
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||
|
||
<ul>
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<li><strong>优化的评论：</strong> 评论在它们保存到服务器之前就显示在列表里,所以感觉很快。</li>
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||
<li><strong>实时更新：</strong> 其他用户的评论被实时浮现到评论中。</li>
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||
<li><strong>Markdown格式化：</strong> 用户可以用Markdown格式化它们的文字。</li>
|
||
</ul>
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<h3><a class="anchor" name=""></a>想要跳过所有内容，只查看源代码？ <a class="hash-link" href="#">#</a></h3>
|
||
<p><a href="https://github.com/reactjs/react-tutorial">全在 GitHub .</a></p>
|
||
<h3><a class="anchor" name=""></a>运行服务器 <a class="hash-link" href="#">#</a></h3>
|
||
<p>为了开始本教程，我们将要需要一个运行着的服务器。这将是我们纯粹用来获取和保存数据的伺服终端。为了让这尽可能的容易，我们已经用许多不同的语言编写了简单的服务器，它正好完成我们需要的事。 <strong>你可以<a href="https://github.com/reactjs/react-tutorial/">查看源代码</a> 或者 <a href="https://github.com/reactjs/react-tutorial/archive/master.zip">下载 zip 文件</a> 包括了所有你开始学习需要的东西</strong></p>
|
||
|
||
<p>为了简单起见，我们将要运行的服务器使用 <code>JSON</code> 文件作为数据库。你不会在生产环境运行这个，但是它让我们更容易模拟使用一个API时你可能会做的事。一旦你启动服务器，它将会支持我们的API终端,同时也将伺服我们需要的静态页面。</p>
|
||
<h3><a class="anchor" name=""></a>开始 <a class="hash-link" href="#">#</a></h3>
|
||
<p>对于此教程,我们将使它尽可能的容易。被包括在上面讨论的服务器包里的是一个我们将在其中工作的 HTML 文件。在你最喜欢的编辑器里打开 <code>public/index.html</code>。它应该看起来像这样 （可能有一些小的不同，稍后我们将添加一个额外的 <code><script></code> 标签）：</p>
|
||
<div class="highlight"><pre><code class="language-html" data-lang="html"><span class="c"><!-- index.html --></span>
|
||
<span class="cp"><!DOCTYPE html></span>
|
||
<span class="nt"><html></span>
|
||
<span class="nt"><head></span>
|
||
<span class="nt"><meta</span> <span class="na">charset=</span><span class="s">"utf-8"</span> <span class="nt">/></span>
|
||
<span class="nt"><title></span>React Tutorial<span class="nt"></title></span>
|
||
<span class="nt"><script </span><span class="na">src=</span><span class="s">"https://cdnjs.cloudflare.com/ajax/libs/react/0.14.6/react.js"</span><span class="nt">></script></span>
|
||
<span class="nt"><script </span><span class="na">src=</span><span class="s">"https://cdnjs.cloudflare.com/ajax/libs/react/0.14.6/react-dom.js"</span><span class="nt">></script></span>
|
||
<span class="nt"><script </span><span class="na">src=</span><span class="s">"https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.23/browser.min.js"</span><span class="nt">></script></span>
|
||
<span class="nt"><script </span><span class="na">src=</span><span class="s">"https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.1/jquery.min.js"</span><span class="nt">></script></span>
|
||
<span class="nt"></head></span>
|
||
<span class="nt"><body></span>
|
||
<span class="nt"><div</span> <span class="na">id=</span><span class="s">"content"</span><span class="nt">></div></span>
|
||
<span class="nt"><script </span><span class="na">type=</span><span class="s">"text/babel"</span> <span class="na">src=</span><span class="s">"scripts/example.js"</span><span class="nt">></script></span>
|
||
<span class="nt"><script </span><span class="na">type=</span><span class="s">"text/babel"</span><span class="nt">></span>
|
||
<span class="c1">// To get started with this tutorial running your own code, simply remove</span>
|
||
<span class="c1">// the script tag loading scripts/example.js and start writing code here.</span>
|
||
<span class="nt"></script></span>
|
||
<span class="nt"></body></span>
|
||
<span class="nt"></html></span>
|
||
</code></pre></div>
|
||
<p>在本教程剩余的部分，我们将在此 script 标签中编写我们的 JavaScript 代码。我们没有任何高级的实时加载所以在保存以后你需要刷新你的浏览器来观察更新。通过在浏览器打开 <code>http://localhost:3000</code> 关注你的进展。当你没有任何修改第一次加载时，你将看到我们将要准备建立的已经完成的产品。当你准备开始工作，请删除前面的 <code><script></code> 标签然后你就可以继续了。</p>
|
||
|
||
<blockquote>
|
||
<p>注意：</p>
|
||
|
||
<p>我们在这里引入 jQuery 是因为我们想简化我们未来的 ajax 请求，但这对React的正常工作 <strong>不是</strong> 必要的。</p>
|
||
</blockquote>
|
||
<h3><a class="anchor" name=""></a>你的第一个组件 <a class="hash-link" href="#">#</a></h3>
|
||
<p>React 中都是关于模块化、可组装的组件。以我们的评论框为例，我们将有如下的组件结构：</p>
|
||
<div class="highlight"><pre><code class="language-text" data-lang="text">- CommentBox
|
||
- CommentList
|
||
- Comment
|
||
- CommentForm
|
||
</code></pre></div>
|
||
<p>让我们构造 <code>CommentBox</code> 组件，仅是一个简单的 <code><div></code> ：</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial1.js</span>
|
||
<span class="kd">var</span> <span class="nx">CommentBox</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">div</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentBox"</span><span class="o">></span>
|
||
<span class="nx">Hello</span><span class="p">,</span> <span class="nx">world</span><span class="o">!</span> <span class="nx">I</span> <span class="nx">am</span> <span class="nx">a</span> <span class="nx">CommentBox</span><span class="p">.</span>
|
||
<span class="o"><</span><span class="err">/div></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
<span class="nx">React</span><span class="p">.</span><span class="nx">render</span><span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">CommentBox</span> <span class="o">/></span><span class="p">,</span>
|
||
<span class="nb">document</span><span class="p">.</span><span class="nx">getElementById</span><span class="p">(</span><span class="s1">'content'</span><span class="p">)</span>
|
||
<span class="p">);</span>
|
||
</code></pre></div>
|
||
<p>注意原生的HTML元素以小写开头，而制定的 React 类以大写开头。</p>
|
||
<h4><a class="anchor" name="jsx-"></a>JSX 语法 <a class="hash-link" href="#jsx-">#</a></h4>
|
||
<p>首先你会注意到你的 JavaScript 中 XML 式的语法。我们有一个简单的预编译器，将这种语法糖转换成单纯的 JavaScript ：</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial1-raw.js</span>
|
||
<span class="kd">var</span> <span class="nx">CommentBox</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span><span class="nx">displayName</span><span class="o">:</span> <span class="s1">'CommentBox'</span><span class="p">,</span>
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="nx">React</span><span class="p">.</span><span class="nx">createElement</span><span class="p">(</span><span class="s1">'div'</span><span class="p">,</span> <span class="p">{</span><span class="nx">className</span><span class="o">:</span> <span class="s2">"commentBox"</span><span class="p">},</span>
|
||
<span class="s2">"Hello, world! I am a CommentBox."</span>
|
||
<span class="p">)</span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
<span class="nx">React</span><span class="p">.</span><span class="nx">render</span><span class="p">(</span>
|
||
<span class="nx">React</span><span class="p">.</span><span class="nx">createElement</span><span class="p">(</span><span class="nx">CommentBox</span><span class="p">,</span> <span class="kc">null</span><span class="p">),</span>
|
||
<span class="nb">document</span><span class="p">.</span><span class="nx">getElementById</span><span class="p">(</span><span class="s1">'content'</span><span class="p">)</span>
|
||
<span class="p">);</span>
|
||
</code></pre></div>
|
||
<p>它的使用是可选的，但是我们发现 JSX 语法比单纯的 JavaScript 更加容易使用。阅读更多关于<a href="/react/docs/jsx-in-depth-zh-CN.html">JSX 语法的文章</a>。</p>
|
||
<h4><a class="anchor" name="whats-going-on"></a>What's going on <a class="hash-link" href="#whats-going-on">#</a></h4>
|
||
<p>我们在一个 JavaScript 对象中传递一些方法到 <code>React.createClass()</code> 来创建一个新的React组件。这些方法中最重要的是 <code>render</code>，该方法返回一颗 React 组件树，这棵树最终将会渲染成 HTML。</p>
|
||
|
||
<p>这个 <code><div></code> 标签不是真实的DOM节点；他们是 React <code>div</code> 组件的实例化。你可以把这些看做是React知道如何处理的标记或者是一些数据 。React 是<strong>安全的</strong>。我们不生成 HTML 字符串，因此XSS防护是默认特性。</p>
|
||
|
||
<p>你没有必要返回基本的 HTML。你可以返回一个你（或者其他人）创建的组件树。这就使 React <strong>组件化</strong>：一个可维护前端的关键原则。</p>
|
||
|
||
<p><code>React.render()</code> 实例化根组件，启动框架，注入标记到原始的 DOM 元素中，作为第二个参数提供。</p>
|
||
<h2><a class="anchor" name=""></a>组合组件 <a class="hash-link" href="#">#</a></h2>
|
||
<p>让我们为 <code>CommentList</code> 和 <code>CommentForm</code> 建造骨架，它们将会，再一次的，是一些简单的 <code><div></code>。添加这两个组件到你的文件里，保持现存的 <code>CommentBox</code> 声明和 <code>React.render</code> 调用:</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial2.js</span>
|
||
<span class="kd">var</span> <span class="nx">CommentList</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">div</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentList"</span><span class="o">></span>
|
||
<span class="nx">Hello</span><span class="p">,</span> <span class="nx">world</span><span class="o">!</span> <span class="nx">I</span> <span class="nx">am</span> <span class="nx">a</span> <span class="nx">CommentList</span><span class="p">.</span>
|
||
<span class="o"><</span><span class="err">/div></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
|
||
<span class="kd">var</span> <span class="nx">CommentForm</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">div</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentForm"</span><span class="o">></span>
|
||
<span class="nx">Hello</span><span class="p">,</span> <span class="nx">world</span><span class="o">!</span> <span class="nx">I</span> <span class="nx">am</span> <span class="nx">a</span> <span class="nx">CommentForm</span><span class="p">.</span>
|
||
<span class="o"><</span><span class="err">/div></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
</code></pre></div>
|
||
<p>接着，更新 <code>CommentBox</code> 以使用这些新的组件：</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial3.js</span>
|
||
<span class="kd">var</span> <span class="nx">CommentBox</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">div</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentBox"</span><span class="o">></span>
|
||
<span class="hll"> <span class="o"><</span><span class="nx">h1</span><span class="o">></span><span class="nx">Comments</span><span class="o"><</span><span class="err">/h1></span>
|
||
</span><span class="hll"> <span class="o"><</span><span class="nx">CommentList</span> <span class="o">/></span>
|
||
</span><span class="hll"> <span class="o"><</span><span class="nx">CommentForm</span> <span class="o">/></span>
|
||
</span> <span class="o"><</span><span class="err">/div></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
</code></pre></div>
|
||
<p>注意我们是如何混合 HTML 标签和我们建立的组件。HTML 组件是正常的 React 组件，就和你定义的一样，只有一个区别。JSX 编译器会自动重写 HTML 标签为 <code>React.createElement(tagName)</code> 表达式，其它什么都不做。这是为了避免污染全局命名空间。</p>
|
||
<h3><a class="anchor" name="-props"></a>使用 props <a class="hash-link" href="#-props">#</a></h3>
|
||
<p>让我们创建 <code>Comment</code> 组件，它将依赖于从父级传来的数据。从父级传来的数据在子组件里作为 '属性' 可供使用。 这些 '属性' 可以通过 <code>this.props</code> 访问。使用属性，我们将能读取从 <code>CommentList</code> 传递给 <code>Comment</code> 的数据，并且渲染一些标记：</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial4.js</span>
|
||
<span class="kd">var</span> <span class="nx">Comment</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">div</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"comment"</span><span class="o">></span>
|
||
<span class="o"><</span><span class="nx">h2</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentAuthor"</span><span class="o">></span>
|
||
<span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">author</span><span class="p">}</span>
|
||
<span class="o"><</span><span class="err">/h2></span>
|
||
<span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">children</span><span class="p">}</span>
|
||
<span class="o"><</span><span class="err">/div></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
</code></pre></div>
|
||
<p>在 JSX 中,通过将 JavaScript 表达式放在大括号中（作为属性或者子节点）,你可以把文本或者 React 组件放置到树中。我们以 <code>this.props</code> 的 keys 访问传递给组件的命名属性，以 <code>this.props.children</code> 访问任何嵌套的元素。</p>
|
||
<h3><a class="anchor" name=""></a>组件的属性 <a class="hash-link" href="#">#</a></h3>
|
||
<p>既然我们已经定义了 <code>Comment</code> 组件，我们将要传递作者名和评论文字给它。这允许我们为每个评论重用相同的代码。现在让我们在我们的 <code>CommentList</code> 里添加一些评论。</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial5.js</span>
|
||
<span class="kd">var</span> <span class="nx">CommentList</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">div</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentList"</span><span class="o">></span>
|
||
<span class="hll"> <span class="o"><</span><span class="nx">Comment</span> <span class="nx">author</span><span class="o">=</span><span class="s2">"Pete Hunt"</span><span class="o">></span><span class="nx">This</span> <span class="nx">is</span> <span class="nx">one</span> <span class="nx">comment</span><span class="o"><</span><span class="err">/Comment></span>
|
||
</span><span class="hll"> <span class="o"><</span><span class="nx">Comment</span> <span class="nx">author</span><span class="o">=</span><span class="s2">"Jordan Walke"</span><span class="o">></span><span class="nx">This</span> <span class="nx">is</span> <span class="o">*</span><span class="nx">another</span><span class="o">*</span> <span class="nx">comment</span><span class="o"><</span><span class="err">/Comment></span>
|
||
</span> <span class="o"><</span><span class="err">/div></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
</code></pre></div>
|
||
<p>注意，我们已经从 <code>CommentList</code> 组件传递了一些数据到 <code>Comment</code> 组件。例如，我们传递了 <em>Pete Hunt</em> （通过属性）和 <em>This is one comment</em> (通过 XML-风格的子节点)给第一个 <code>Comment</code>。如上面提到的那样， <code>Comment</code> 组件将会通过 <code>this.props.author</code> 和 <code>this.props.children</code> 访问 这些 '属性'。</p>
|
||
<h3><a class="anchor" name="-markdown"></a>添加 Markdown <a class="hash-link" href="#-markdown">#</a></h3>
|
||
<p>Markdown 是一种简单的内联格式化你的文字的方法。例如，用星号包围文本将会使其强调突出。</p>
|
||
|
||
<p>首先，添加第三方库 <strong>marked</strong> 到你的应用。这是一个JavaScript库，接受 Markdown 文本并且转换为原始的 HTML。这需要在你的头部有一个 script 标签（那个我们已经在 React 操场上包含了的标签）：</p>
|
||
<div class="highlight"><pre><code class="language-html" data-lang="html"><span class="c"><!-- index.html --></span>
|
||
<span class="nt"><head></span>
|
||
<span class="nt"><meta</span> <span class="na">charset=</span><span class="s">"utf-8"</span> <span class="nt">/></span>
|
||
<span class="nt"><title></span>React Tutorial<span class="nt"></title></span>
|
||
<span class="nt"><script </span><span class="na">src=</span><span class="s">"https://cdnjs.cloudflare.com/ajax/libs/react/0.14.6/react.js"</span><span class="nt">></script></span>
|
||
<span class="nt"><script </span><span class="na">src=</span><span class="s">"https://cdnjs.cloudflare.com/ajax/libs/react/0.14.6/react-dom.js"</span><span class="nt">></script></span>
|
||
<span class="nt"><script </span><span class="na">src=</span><span class="s">"https://cdnjs.cloudflare.com/ajax/libs/babel-core/5.8.23/browser.min.js"</span><span class="nt">></script></span>
|
||
<span class="nt"><script </span><span class="na">src=</span><span class="s">"https://cdnjs.cloudflare.com/ajax/libs/jquery/2.1.1/jquery.min.js"</span><span class="nt">></script></span>
|
||
<span class="hll"> <span class="nt"><script </span><span class="na">src=</span><span class="s">"https://cdnjs.cloudflare.com/ajax/libs/marked/0.3.2/marked.min.js"</span><span class="nt">></script></span>
|
||
</span><span class="nt"></head></span>
|
||
</code></pre></div>
|
||
<p>然后，让我们转换评论文本为 Markdown 并输出它：</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial6.js</span>
|
||
<span class="kd">var</span> <span class="nx">Comment</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">div</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"comment"</span><span class="o">></span>
|
||
<span class="o"><</span><span class="nx">h2</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentAuthor"</span><span class="o">></span>
|
||
<span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">author</span><span class="p">}</span>
|
||
<span class="o"><</span><span class="err">/h2></span>
|
||
<span class="hll"> <span class="p">{</span><span class="nx">marked</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">children</span><span class="p">.</span><span class="nx">toString</span><span class="p">())}</span>
|
||
</span> <span class="o"><</span><span class="err">/div></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
</code></pre></div>
|
||
<p>我们在这里唯一做的就是调用 marked 库。我们需要把 从 React 的包裹文本来的 <code>this.props.children</code> 转换成 marked 能理解的原始字符串，所以我们显示地调用了<code>toString()</code>。</p>
|
||
|
||
<p>但是这里有一个问题！我们渲染的评论在浏览器里看起来像这样： "<code><p></code>This is <code><em></code>another<code></em></code> comment<code></p></code>" 。我们想让这些标签真正地渲染为 HTML。</p>
|
||
|
||
<p>那是 React 在保护你免受 <a href="https://en.wikipedia.org/wiki/Cross-site_scripting">XSS 攻击</a>。有一个方法解决这个问题，但是框架会警告你别使用这种方法：</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial7.js</span>
|
||
<span class="kd">var</span> <span class="nx">Comment</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="nx">rawMarkup</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="hll"> <span class="kd">var</span> <span class="nx">rawMarkup</span> <span class="o">=</span> <span class="nx">marked</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">children</span><span class="p">.</span><span class="nx">toString</span><span class="p">(),</span> <span class="p">{</span><span class="nx">sanitize</span><span class="o">:</span> <span class="kc">true</span><span class="p">});</span>
|
||
</span> <span class="k">return</span> <span class="p">{</span> <span class="nx">__html</span><span class="o">:</span> <span class="nx">rawMarkup</span> <span class="p">};</span>
|
||
<span class="p">},</span>
|
||
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="hll"> <span class="o"><</span><span class="nx">div</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"comment"</span><span class="o">></span>
|
||
</span> <span class="o"><</span><span class="nx">h2</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentAuthor"</span><span class="o">></span>
|
||
<span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">author</span><span class="p">}</span>
|
||
<span class="o"><</span><span class="err">/h2></span>
|
||
<span class="o"><</span><span class="nx">span</span> <span class="nx">dangerouslySetInnerHTML</span><span class="o">=</span><span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">rawMarkup</span><span class="p">()}</span> <span class="o">/></span>
|
||
<span class="o"><</span><span class="err">/div></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
</code></pre></div>
|
||
<p>这是一个特殊的 API，故意让插入原始的 HTML 变得困难，但是对于 marked 我们将利用这个后门。</p>
|
||
|
||
<p><strong>记住：</strong> 使用这个功能你会依赖于 marked 是安全的。既然如此，我们传递 <code>sanitize: true</code> 告诉 marked escape 源码里任何的 HTML 标记，而不是直接不变的让他们通过。</p>
|
||
<h3><a class="anchor" name=""></a>挂钩数据模型 <a class="hash-link" href="#">#</a></h3>
|
||
<p>到目前为止我们已经完成了在源码里直接插入评论。作为替代，让我们渲染一团 JSON 数据到评论列表里。最终数据将会来自服务器，但是现在，写在你的源代码中：</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial8.js</span>
|
||
<span class="kd">var</span> <span class="nx">data</span> <span class="o">=</span> <span class="p">[</span>
|
||
<span class="p">{</span><span class="nx">author</span><span class="o">:</span> <span class="s2">"Pete Hunt"</span><span class="p">,</span> <span class="nx">text</span><span class="o">:</span> <span class="s2">"This is one comment"</span><span class="p">},</span>
|
||
<span class="p">{</span><span class="nx">author</span><span class="o">:</span> <span class="s2">"Jordan Walke"</span><span class="p">,</span> <span class="nx">text</span><span class="o">:</span> <span class="s2">"This is *another* comment"</span><span class="p">}</span>
|
||
<span class="p">];</span>
|
||
</code></pre></div>
|
||
<p>我们需要以一种模块化的方式将这个数据传入到 <code>CommentList</code>。修改 <code>CommentBox</code> 和 <code>React.render()</code> 方法，以通过 props 传入数据到 <code>CommentList</code>：</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial9.js</span>
|
||
<span class="kd">var</span> <span class="nx">CommentBox</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">div</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentBox"</span><span class="o">></span>
|
||
<span class="o"><</span><span class="nx">h1</span><span class="o">></span><span class="nx">Comments</span><span class="o"><</span><span class="err">/h1></span>
|
||
<span class="hll"> <span class="o"><</span><span class="nx">CommentList</span> <span class="nx">data</span><span class="o">=</span><span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">data</span><span class="p">}</span> <span class="o">/></span>
|
||
</span> <span class="o"><</span><span class="nx">CommentForm</span> <span class="o">/></span>
|
||
<span class="o"><</span><span class="err">/div></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
|
||
<span class="nx">React</span><span class="p">.</span><span class="nx">render</span><span class="p">(</span>
|
||
<span class="hll"> <span class="o"><</span><span class="nx">CommentBox</span> <span class="nx">data</span><span class="o">=</span><span class="p">{</span><span class="nx">data</span><span class="p">}</span> <span class="o">/></span><span class="p">,</span>
|
||
</span> <span class="nb">document</span><span class="p">.</span><span class="nx">getElementById</span><span class="p">(</span><span class="s1">'content'</span><span class="p">)</span>
|
||
<span class="p">);</span>
|
||
</code></pre></div>
|
||
<p>既然现在数据在 <code>CommentList</code> 中可用了，让我们动态地渲染评论：</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial10.js</span>
|
||
<span class="kd">var</span> <span class="nx">CommentList</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="hll"> <span class="kd">var</span> <span class="nx">commentNodes</span> <span class="o">=</span> <span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">data</span><span class="p">.</span><span class="nx">map</span><span class="p">(</span><span class="kd">function</span> <span class="p">(</span><span class="nx">comment</span><span class="p">)</span> <span class="p">{</span>
|
||
</span><span class="hll"> <span class="k">return</span> <span class="p">(</span>
|
||
</span><span class="hll"> <span class="o"><</span><span class="nx">Comment</span> <span class="nx">author</span><span class="o">=</span><span class="p">{</span><span class="nx">comment</span><span class="p">.</span><span class="nx">author</span><span class="p">}</span><span class="o">></span>
|
||
</span><span class="hll"> <span class="p">{</span><span class="nx">comment</span><span class="p">.</span><span class="nx">text</span><span class="p">}</span>
|
||
</span><span class="hll"> <span class="o"><</span><span class="err">/Comment></span>
|
||
</span><span class="hll"> <span class="p">);</span>
|
||
</span><span class="hll"> <span class="p">});</span>
|
||
</span> <span class="k">return</span> <span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">div</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentList"</span><span class="o">></span>
|
||
<span class="hll"> <span class="p">{</span><span class="nx">commentNodes</span><span class="p">}</span>
|
||
</span> <span class="o"><</span><span class="err">/div></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
</code></pre></div>
|
||
<p>就是这样！</p>
|
||
<h3><a class="anchor" name=""></a>从服务器获取数据 <a class="hash-link" href="#">#</a></h3>
|
||
<p>让我们用一些来自服务器的动态数据替换硬编码的数据。我们将移除数据的prop，用获取数据的URL来替换它：</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial11.js</span>
|
||
<span class="nx">React</span><span class="p">.</span><span class="nx">render</span><span class="p">(</span>
|
||
<span class="hll"> <span class="o"><</span><span class="nx">CommentBox</span> <span class="nx">url</span><span class="o">=</span><span class="s2">"/api/comments"</span> <span class="o">/></span><span class="p">,</span>
|
||
</span> <span class="nb">document</span><span class="p">.</span><span class="nx">getElementById</span><span class="p">(</span><span class="s1">'content'</span><span class="p">)</span>
|
||
<span class="p">);</span>
|
||
</code></pre></div>
|
||
<p>这个组件不同于和前面的组件，因为它必须重新渲染自己。该组件将不会有任何数据，直到请求从服务器返回，此时该组件或许需要渲染一些新的评论。</p>
|
||
|
||
<p>注意： 此代码在这个阶段不会工作。</p>
|
||
<h3><a class="anchor" name="reactive-state"></a>Reactive state <a class="hash-link" href="#reactive-state">#</a></h3>
|
||
<p>迄今为止,基于它自己的props，每个组件都渲染了自己一次。<code>props</code> 是不可变的：它们从父级传来并被父级“拥有”。为了实现交互，我们给组件引进了可变的 <strong>state</strong>。<code>this.state</code> 是组件私有的，可以通过调用 <code>this.setState()</code> 改变它。每当state更新，组件就重新渲染自己。</p>
|
||
|
||
<p><code>render()</code> 方法被声明为一个带有 <code>this.props</code> 和 <code>this.state</code> 的函数。框架保证了 UI 总是与输入一致。</p>
|
||
|
||
<p>当服务器获取数据时，我们将会改变我们已有的评论数据。让我们给 <code>CommentBox</code> 组件添加一组评论数据作为它的状态：</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial12.js</span>
|
||
<span class="kd">var</span> <span class="nx">CommentBox</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="hll"> <span class="nx">getInitialState</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
</span><span class="hll"> <span class="k">return</span> <span class="p">{</span><span class="nx">data</span><span class="o">:</span> <span class="p">[]};</span>
|
||
</span><span class="hll"> <span class="p">},</span>
|
||
</span> <span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">div</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentBox"</span><span class="o">></span>
|
||
<span class="o"><</span><span class="nx">h1</span><span class="o">></span><span class="nx">Comments</span><span class="o"><</span><span class="err">/h1></span>
|
||
<span class="hll"> <span class="o"><</span><span class="nx">CommentList</span> <span class="nx">data</span><span class="o">=</span><span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">state</span><span class="p">.</span><span class="nx">data</span><span class="p">}</span> <span class="o">/></span>
|
||
</span> <span class="o"><</span><span class="nx">CommentForm</span> <span class="o">/></span>
|
||
<span class="o"><</span><span class="err">/div></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
</code></pre></div>
|
||
<p><code>getInitialState()</code> 在生命周期里只执行一次，并设置组件的初始状态。</p>
|
||
<h4><a class="anchor" name=""></a>更新状态 <a class="hash-link" href="#">#</a></h4>
|
||
<p>当组件第一次创建时，我们想从服务器获取一些 JSON 并且更新状态以反映最新的数据。我们将用 jQuery 来发送一个异步请求到我们刚才启动的服务器以获取我们需要的数据。看起来像这样：</p>
|
||
<div class="highlight"><pre><code class="language-json" data-lang="json"><span class="p">[</span>
|
||
<span class="p">{</span><span class="nt">"author"</span><span class="p">:</span> <span class="s2">"Pete Hunt"</span><span class="p">,</span> <span class="nt">"text"</span><span class="p">:</span> <span class="s2">"This is one comment"</span><span class="p">},</span>
|
||
<span class="p">{</span><span class="nt">"author"</span><span class="p">:</span> <span class="s2">"Jordan Walke"</span><span class="p">,</span> <span class="nt">"text"</span><span class="p">:</span> <span class="s2">"This is *another* comment"</span><span class="p">}</span>
|
||
<span class="p">]</span>
|
||
</code></pre></div><div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial13.js</span>
|
||
<span class="kd">var</span> <span class="nx">CommentBox</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="nx">getInitialState</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">{</span><span class="nx">data</span><span class="o">:</span> <span class="p">[]};</span>
|
||
<span class="p">},</span>
|
||
<span class="hll"> <span class="nx">componentDidMount</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
</span><span class="hll"> <span class="nx">$</span><span class="p">.</span><span class="nx">ajax</span><span class="p">({</span>
|
||
</span><span class="hll"> <span class="nx">url</span><span class="o">:</span> <span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">url</span><span class="p">,</span>
|
||
</span><span class="hll"> <span class="nx">dataType</span><span class="o">:</span> <span class="s1">'json'</span><span class="p">,</span>
|
||
</span><span class="hll"> <span class="nx">cache</span><span class="o">:</span> <span class="kc">false</span><span class="p">,</span>
|
||
</span><span class="hll"> <span class="nx">success</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">data</span><span class="p">)</span> <span class="p">{</span>
|
||
</span><span class="hll"> <span class="k">this</span><span class="p">.</span><span class="nx">setState</span><span class="p">({</span><span class="nx">data</span><span class="o">:</span> <span class="nx">data</span><span class="p">});</span>
|
||
</span><span class="hll"> <span class="p">}.</span><span class="nx">bind</span><span class="p">(</span><span class="k">this</span><span class="p">),</span>
|
||
</span><span class="hll"> <span class="nx">error</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">xhr</span><span class="p">,</span> <span class="nx">status</span><span class="p">,</span> <span class="nx">err</span><span class="p">)</span> <span class="p">{</span>
|
||
</span><span class="hll"> <span class="nx">console</span><span class="p">.</span><span class="nx">error</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">url</span><span class="p">,</span> <span class="nx">status</span><span class="p">,</span> <span class="nx">err</span><span class="p">.</span><span class="nx">toString</span><span class="p">());</span>
|
||
</span><span class="hll"> <span class="p">}.</span><span class="nx">bind</span><span class="p">(</span><span class="k">this</span><span class="p">)</span>
|
||
</span><span class="hll"> <span class="p">});</span>
|
||
</span><span class="hll"> <span class="p">},</span>
|
||
</span> <span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">div</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentBox"</span><span class="o">></span>
|
||
<span class="o"><</span><span class="nx">h1</span><span class="o">></span><span class="nx">Comments</span><span class="o"><</span><span class="err">/h1></span>
|
||
<span class="o"><</span><span class="nx">CommentList</span> <span class="nx">data</span><span class="o">=</span><span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">state</span><span class="p">.</span><span class="nx">data</span><span class="p">}</span> <span class="o">/></span>
|
||
<span class="o"><</span><span class="nx">CommentForm</span> <span class="o">/></span>
|
||
<span class="o"><</span><span class="err">/div></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
</code></pre></div>
|
||
<p>这里， <code>componentDidMount</code> 是一个当组件被渲染时被Ｒeact自动调用的方法。动态更新的关键是对 <code>this.setState()</code> 的调用。我们用新的从服务器来的替换掉旧的评论组，然后UI自动更新自己。因为这种反应性，仅是一个微小的变化就添加了实时更新。我们这里将用简单的轮询，但是你可以容易的使用 WebSockets 或者其他技术。</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial14.js</span>
|
||
<span class="kd">var</span> <span class="nx">CommentBox</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="hll"> <span class="nx">loadCommentsFromServer</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
</span> <span class="nx">$</span><span class="p">.</span><span class="nx">ajax</span><span class="p">({</span>
|
||
<span class="nx">url</span><span class="o">:</span> <span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">url</span><span class="p">,</span>
|
||
<span class="nx">dataType</span><span class="o">:</span> <span class="s1">'json'</span><span class="p">,</span>
|
||
<span class="nx">cache</span><span class="o">:</span> <span class="kc">false</span><span class="p">,</span>
|
||
<span class="nx">success</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">data</span><span class="p">)</span> <span class="p">{</span>
|
||
<span class="k">this</span><span class="p">.</span><span class="nx">setState</span><span class="p">({</span><span class="nx">data</span><span class="o">:</span> <span class="nx">data</span><span class="p">});</span>
|
||
<span class="p">}.</span><span class="nx">bind</span><span class="p">(</span><span class="k">this</span><span class="p">),</span>
|
||
<span class="nx">error</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">xhr</span><span class="p">,</span> <span class="nx">status</span><span class="p">,</span> <span class="nx">err</span><span class="p">)</span> <span class="p">{</span>
|
||
<span class="nx">console</span><span class="p">.</span><span class="nx">error</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">url</span><span class="p">,</span> <span class="nx">status</span><span class="p">,</span> <span class="nx">err</span><span class="p">.</span><span class="nx">toString</span><span class="p">());</span>
|
||
<span class="p">}.</span><span class="nx">bind</span><span class="p">(</span><span class="k">this</span><span class="p">)</span>
|
||
<span class="p">});</span>
|
||
<span class="hll"> <span class="p">},</span>
|
||
</span> <span class="nx">getInitialState</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">{</span><span class="nx">data</span><span class="o">:</span> <span class="p">[]};</span>
|
||
<span class="p">},</span>
|
||
<span class="nx">componentDidMount</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="hll"> <span class="k">this</span><span class="p">.</span><span class="nx">loadCommentsFromServer</span><span class="p">();</span>
|
||
</span><span class="hll"> <span class="nx">setInterval</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">loadCommentsFromServer</span><span class="p">,</span> <span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">pollInterval</span><span class="p">);</span>
|
||
</span> <span class="p">},</span>
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">div</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentBox"</span><span class="o">></span>
|
||
<span class="o"><</span><span class="nx">h1</span><span class="o">></span><span class="nx">Comments</span><span class="o"><</span><span class="err">/h1></span>
|
||
<span class="o"><</span><span class="nx">CommentList</span> <span class="nx">data</span><span class="o">=</span><span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">state</span><span class="p">.</span><span class="nx">data</span><span class="p">}</span> <span class="o">/></span>
|
||
<span class="o"><</span><span class="nx">CommentForm</span> <span class="o">/></span>
|
||
<span class="o"><</span><span class="err">/div></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
|
||
<span class="nx">React</span><span class="p">.</span><span class="nx">render</span><span class="p">(</span>
|
||
<span class="hll"> <span class="o"><</span><span class="nx">CommentBox</span> <span class="nx">url</span><span class="o">=</span><span class="s2">"/api/comments"</span> <span class="nx">pollInterval</span><span class="o">=</span><span class="p">{</span><span class="mi">2000</span><span class="p">}</span> <span class="o">/></span><span class="p">,</span>
|
||
</span> <span class="nb">document</span><span class="p">.</span><span class="nx">getElementById</span><span class="p">(</span><span class="s1">'content'</span><span class="p">)</span>
|
||
<span class="p">);</span>
|
||
</code></pre></div>
|
||
<p>我们在这里做的全部事情是把 AJAX 调用移动到独立的方法里，然后在组件第一次加载时及其后每2秒 调用它。试着在你的浏览器里运行它并且改变 <code>comments.json</code> 文件（在你的服务器的相同目录）；2秒内，变化将会显现！</p>
|
||
<h3><a class="anchor" name=""></a>添加新评论 <a class="hash-link" href="#">#</a></h3>
|
||
<p>现在是时候建立表单了，我们的 <code>CommentForm</code> 组件应该询问用户他们的名字和评论文本然后发送一个请求到服务器来保存评论.</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial15.js</span>
|
||
<span class="kd">var</span> <span class="nx">CommentForm</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="hll"> <span class="o"><</span><span class="nx">form</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentForm"</span><span class="o">></span>
|
||
</span><span class="hll"> <span class="o"><</span><span class="nx">input</span> <span class="nx">type</span><span class="o">=</span><span class="s2">"text"</span> <span class="nx">placeholder</span><span class="o">=</span><span class="s2">"Your name"</span> <span class="o">/></span>
|
||
</span><span class="hll"> <span class="o"><</span><span class="nx">input</span> <span class="nx">type</span><span class="o">=</span><span class="s2">"text"</span> <span class="nx">placeholder</span><span class="o">=</span><span class="s2">"Say something..."</span> <span class="o">/></span>
|
||
</span><span class="hll"> <span class="o"><</span><span class="nx">input</span> <span class="nx">type</span><span class="o">=</span><span class="s2">"submit"</span> <span class="nx">value</span><span class="o">=</span><span class="s2">"Post"</span> <span class="o">/></span>
|
||
</span><span class="hll"> <span class="o"><</span><span class="err">/form></span>
|
||
</span> <span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
</code></pre></div>
|
||
<p>让我们做一个交互式的表单。当用户提交表单时，我们应该清空它，提交一个请求给服务器，和刷新评论列表。要开始，让我们监听表单的提交事件并清空它。</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial16.js</span>
|
||
<span class="kd">var</span> <span class="nx">CommentForm</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="hll"> <span class="nx">handleSubmit</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">e</span><span class="p">)</span> <span class="p">{</span>
|
||
</span><span class="hll"> <span class="nx">e</span><span class="p">.</span><span class="nx">preventDefault</span><span class="p">();</span>
|
||
</span><span class="hll"> <span class="kd">var</span> <span class="nx">author</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">findDOMNode</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">refs</span><span class="p">.</span><span class="nx">author</span><span class="p">).</span><span class="nx">value</span><span class="p">.</span><span class="nx">trim</span><span class="p">();</span>
|
||
</span><span class="hll"> <span class="kd">var</span> <span class="nx">text</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">findDOMNode</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">refs</span><span class="p">.</span><span class="nx">text</span><span class="p">).</span><span class="nx">value</span><span class="p">.</span><span class="nx">trim</span><span class="p">();</span>
|
||
</span><span class="hll"> <span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">text</span> <span class="o">||</span> <span class="o">!</span><span class="nx">author</span><span class="p">)</span> <span class="p">{</span>
|
||
</span><span class="hll"> <span class="k">return</span><span class="p">;</span>
|
||
</span><span class="hll"> <span class="p">}</span>
|
||
</span><span class="hll"> <span class="c1">// TODO: send request to the server</span>
|
||
</span><span class="hll"> <span class="nx">React</span><span class="p">.</span><span class="nx">findDOMNode</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">refs</span><span class="p">.</span><span class="nx">author</span><span class="p">).</span><span class="nx">value</span> <span class="o">=</span> <span class="s1">''</span><span class="p">;</span>
|
||
</span><span class="hll"> <span class="nx">React</span><span class="p">.</span><span class="nx">findDOMNode</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">refs</span><span class="p">.</span><span class="nx">text</span><span class="p">).</span><span class="nx">value</span> <span class="o">=</span> <span class="s1">''</span><span class="p">;</span>
|
||
</span><span class="hll"> <span class="k">return</span><span class="p">;</span>
|
||
</span><span class="hll"> <span class="p">},</span>
|
||
</span> <span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="hll"> <span class="k">return</span> <span class="p">(</span>
|
||
</span><span class="hll"> <span class="o"><</span><span class="nx">form</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentForm"</span> <span class="nx">onSubmit</span><span class="o">=</span><span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">handleSubmit</span><span class="p">}</span><span class="o">></span>
|
||
</span><span class="hll"> <span class="o"><</span><span class="nx">input</span> <span class="nx">type</span><span class="o">=</span><span class="s2">"text"</span> <span class="nx">placeholder</span><span class="o">=</span><span class="s2">"Your name"</span> <span class="nx">ref</span><span class="o">=</span><span class="s2">"author"</span> <span class="o">/></span>
|
||
</span><span class="hll"> <span class="o"><</span><span class="nx">input</span> <span class="nx">type</span><span class="o">=</span><span class="s2">"text"</span> <span class="nx">placeholder</span><span class="o">=</span><span class="s2">"Say something..."</span> <span class="nx">ref</span><span class="o">=</span><span class="s2">"text"</span> <span class="o">/></span>
|
||
</span> <span class="o"><</span><span class="nx">input</span> <span class="nx">type</span><span class="o">=</span><span class="s2">"submit"</span> <span class="nx">value</span><span class="o">=</span><span class="s2">"Post"</span> <span class="o">/></span>
|
||
<span class="o"><</span><span class="err">/form></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
</code></pre></div><h5><a class="anchor" name=""></a>事件 <a class="hash-link" href="#">#</a></h5>
|
||
<p>React使用驼峰命名规范(camelCase)给组件绑定事件处理器。我们给表单绑定一个<code>onSubmit</code>处理器，它在表单提交了合法的输入后清空表单字段。</p>
|
||
|
||
<p>在事件中调用<code>preventDefault()</code>来阻止浏览器提交表单的默认行为。</p>
|
||
<h5><a class="anchor" name="refs"></a>Refs <a class="hash-link" href="#refs">#</a></h5>
|
||
<p>我们利用<code>ref</code>属性给子组件赋予名字，<code>this.refs</code>-引用组件。我们可以在组件上调用 <code>React.findDOMNode(component)</code> 获取原生的浏览器DOM元素。</p>
|
||
<h5><a class="anchor" name=""></a>回调函数作为属性 <a class="hash-link" href="#">#</a></h5>
|
||
<p>当用户提交评论时，我们需要刷新评论列表来包含这条新评论。在<code>CommentBox</code>中完成所有逻辑是有道理的，因为<code>CommentBox</code> 拥有代表了评论列表的状态(state)。</p>
|
||
|
||
<p>我们需要从子组件传回数据到它的父组件。我们在父组件的<code>render</code>方法中以传递一个新的回调函数（<code>handleCommentSubmit</code>）到子组件完成这件事，绑定它到子组件的 <code>onCommentSubmit</code> 事件上。无论事件什么时候触发，回调函数都将被调用：</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial17.js</span>
|
||
<span class="kd">var</span> <span class="nx">CommentBox</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="nx">loadCommentsFromServer</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="nx">$</span><span class="p">.</span><span class="nx">ajax</span><span class="p">({</span>
|
||
<span class="nx">url</span><span class="o">:</span> <span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">url</span><span class="p">,</span>
|
||
<span class="nx">dataType</span><span class="o">:</span> <span class="s1">'json'</span><span class="p">,</span>
|
||
<span class="nx">cache</span><span class="o">:</span> <span class="kc">false</span><span class="p">,</span>
|
||
<span class="nx">success</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">data</span><span class="p">)</span> <span class="p">{</span>
|
||
<span class="k">this</span><span class="p">.</span><span class="nx">setState</span><span class="p">({</span><span class="nx">data</span><span class="o">:</span> <span class="nx">data</span><span class="p">});</span>
|
||
<span class="p">}.</span><span class="nx">bind</span><span class="p">(</span><span class="k">this</span><span class="p">),</span>
|
||
<span class="nx">error</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">xhr</span><span class="p">,</span> <span class="nx">status</span><span class="p">,</span> <span class="nx">err</span><span class="p">)</span> <span class="p">{</span>
|
||
<span class="nx">console</span><span class="p">.</span><span class="nx">error</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">url</span><span class="p">,</span> <span class="nx">status</span><span class="p">,</span> <span class="nx">err</span><span class="p">.</span><span class="nx">toString</span><span class="p">());</span>
|
||
<span class="p">}.</span><span class="nx">bind</span><span class="p">(</span><span class="k">this</span><span class="p">)</span>
|
||
<span class="p">});</span>
|
||
<span class="p">},</span>
|
||
<span class="hll"> <span class="nx">handleCommentSubmit</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">comment</span><span class="p">)</span> <span class="p">{</span>
|
||
</span><span class="hll"> <span class="c1">// TODO: submit to the server and refresh the list</span>
|
||
</span><span class="hll"> <span class="p">},</span>
|
||
</span> <span class="nx">getInitialState</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">{</span><span class="nx">data</span><span class="o">:</span> <span class="p">[]};</span>
|
||
<span class="p">},</span>
|
||
<span class="nx">componentDidMount</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">this</span><span class="p">.</span><span class="nx">loadCommentsFromServer</span><span class="p">();</span>
|
||
<span class="nx">setInterval</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">loadCommentsFromServer</span><span class="p">,</span> <span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">pollInterval</span><span class="p">);</span>
|
||
<span class="p">},</span>
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">div</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentBox"</span><span class="o">></span>
|
||
<span class="o"><</span><span class="nx">h1</span><span class="o">></span><span class="nx">Comments</span><span class="o"><</span><span class="err">/h1></span>
|
||
<span class="o"><</span><span class="nx">CommentList</span> <span class="nx">data</span><span class="o">=</span><span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">state</span><span class="p">.</span><span class="nx">data</span><span class="p">}</span> <span class="o">/></span>
|
||
<span class="hll"> <span class="o"><</span><span class="nx">CommentForm</span> <span class="nx">onCommentSubmit</span><span class="o">=</span><span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">handleCommentSubmit</span><span class="p">}</span> <span class="o">/></span>
|
||
</span> <span class="o"><</span><span class="err">/div></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
</code></pre></div>
|
||
<p>当用户提交表单时，让我们从 <code>CommentForm</code> 调用这个回调函数：</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial18.js</span>
|
||
<span class="kd">var</span> <span class="nx">CommentForm</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="nx">handleSubmit</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">e</span><span class="p">)</span> <span class="p">{</span>
|
||
<span class="nx">e</span><span class="p">.</span><span class="nx">preventDefault</span><span class="p">();</span>
|
||
<span class="kd">var</span> <span class="nx">author</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">findDOMNode</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">refs</span><span class="p">.</span><span class="nx">author</span><span class="p">).</span><span class="nx">value</span><span class="p">.</span><span class="nx">trim</span><span class="p">();</span>
|
||
<span class="kd">var</span> <span class="nx">text</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">findDOMNode</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">refs</span><span class="p">.</span><span class="nx">text</span><span class="p">).</span><span class="nx">value</span><span class="p">.</span><span class="nx">trim</span><span class="p">();</span>
|
||
<span class="k">if</span> <span class="p">(</span><span class="o">!</span><span class="nx">text</span> <span class="o">||</span> <span class="o">!</span><span class="nx">author</span><span class="p">)</span> <span class="p">{</span>
|
||
<span class="k">return</span><span class="p">;</span>
|
||
<span class="p">}</span>
|
||
<span class="hll"> <span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">onCommentSubmit</span><span class="p">({</span><span class="nx">author</span><span class="o">:</span> <span class="nx">author</span><span class="p">,</span> <span class="nx">text</span><span class="o">:</span> <span class="nx">text</span><span class="p">});</span>
|
||
</span> <span class="nx">React</span><span class="p">.</span><span class="nx">findDOMNode</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">refs</span><span class="p">.</span><span class="nx">author</span><span class="p">).</span><span class="nx">value</span> <span class="o">=</span> <span class="s1">''</span><span class="p">;</span>
|
||
<span class="nx">React</span><span class="p">.</span><span class="nx">findDOMNode</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">refs</span><span class="p">.</span><span class="nx">text</span><span class="p">).</span><span class="nx">value</span> <span class="o">=</span> <span class="s1">''</span><span class="p">;</span>
|
||
<span class="k">return</span><span class="p">;</span>
|
||
<span class="p">},</span>
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">form</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentForm"</span> <span class="nx">onSubmit</span><span class="o">=</span><span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">handleSubmit</span><span class="p">}</span><span class="o">></span>
|
||
<span class="o"><</span><span class="nx">input</span> <span class="nx">type</span><span class="o">=</span><span class="s2">"text"</span> <span class="nx">placeholder</span><span class="o">=</span><span class="s2">"Your name"</span> <span class="nx">ref</span><span class="o">=</span><span class="s2">"author"</span> <span class="o">/></span>
|
||
<span class="o"><</span><span class="nx">input</span> <span class="nx">type</span><span class="o">=</span><span class="s2">"text"</span> <span class="nx">placeholder</span><span class="o">=</span><span class="s2">"Say something..."</span> <span class="nx">ref</span><span class="o">=</span><span class="s2">"text"</span> <span class="o">/></span>
|
||
<span class="o"><</span><span class="nx">input</span> <span class="nx">type</span><span class="o">=</span><span class="s2">"submit"</span> <span class="nx">value</span><span class="o">=</span><span class="s2">"Post"</span> <span class="o">/></span>
|
||
<span class="o"><</span><span class="err">/form></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
</code></pre></div>
|
||
<p>既然现在回调函数已经就绪，我们所需要做的就是提交到服务器然后刷新列表：</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial19.js</span>
|
||
<span class="kd">var</span> <span class="nx">CommentBox</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="nx">loadCommentsFromServer</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="nx">$</span><span class="p">.</span><span class="nx">ajax</span><span class="p">({</span>
|
||
<span class="nx">url</span><span class="o">:</span> <span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">url</span><span class="p">,</span>
|
||
<span class="nx">dataType</span><span class="o">:</span> <span class="s1">'json'</span><span class="p">,</span>
|
||
<span class="nx">cache</span><span class="o">:</span> <span class="kc">false</span><span class="p">,</span>
|
||
<span class="nx">success</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">data</span><span class="p">)</span> <span class="p">{</span>
|
||
<span class="k">this</span><span class="p">.</span><span class="nx">setState</span><span class="p">({</span><span class="nx">data</span><span class="o">:</span> <span class="nx">data</span><span class="p">});</span>
|
||
<span class="p">}.</span><span class="nx">bind</span><span class="p">(</span><span class="k">this</span><span class="p">),</span>
|
||
<span class="nx">error</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">xhr</span><span class="p">,</span> <span class="nx">status</span><span class="p">,</span> <span class="nx">err</span><span class="p">)</span> <span class="p">{</span>
|
||
<span class="nx">console</span><span class="p">.</span><span class="nx">error</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">url</span><span class="p">,</span> <span class="nx">status</span><span class="p">,</span> <span class="nx">err</span><span class="p">.</span><span class="nx">toString</span><span class="p">());</span>
|
||
<span class="p">}.</span><span class="nx">bind</span><span class="p">(</span><span class="k">this</span><span class="p">)</span>
|
||
<span class="p">});</span>
|
||
<span class="p">},</span>
|
||
<span class="nx">handleCommentSubmit</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">comment</span><span class="p">)</span> <span class="p">{</span>
|
||
<span class="hll"> <span class="nx">$</span><span class="p">.</span><span class="nx">ajax</span><span class="p">({</span>
|
||
</span><span class="hll"> <span class="nx">url</span><span class="o">:</span> <span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">url</span><span class="p">,</span>
|
||
</span><span class="hll"> <span class="nx">dataType</span><span class="o">:</span> <span class="s1">'json'</span><span class="p">,</span>
|
||
</span><span class="hll"> <span class="nx">type</span><span class="o">:</span> <span class="s1">'POST'</span><span class="p">,</span>
|
||
</span><span class="hll"> <span class="nx">data</span><span class="o">:</span> <span class="nx">comment</span><span class="p">,</span>
|
||
</span><span class="hll"> <span class="nx">success</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">data</span><span class="p">)</span> <span class="p">{</span>
|
||
</span><span class="hll"> <span class="k">this</span><span class="p">.</span><span class="nx">setState</span><span class="p">({</span><span class="nx">data</span><span class="o">:</span> <span class="nx">data</span><span class="p">});</span>
|
||
</span><span class="hll"> <span class="p">}.</span><span class="nx">bind</span><span class="p">(</span><span class="k">this</span><span class="p">),</span>
|
||
</span><span class="hll"> <span class="nx">error</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">xhr</span><span class="p">,</span> <span class="nx">status</span><span class="p">,</span> <span class="nx">err</span><span class="p">)</span> <span class="p">{</span>
|
||
</span><span class="hll"> <span class="nx">console</span><span class="p">.</span><span class="nx">error</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">url</span><span class="p">,</span> <span class="nx">status</span><span class="p">,</span> <span class="nx">err</span><span class="p">.</span><span class="nx">toString</span><span class="p">());</span>
|
||
</span><span class="hll"> <span class="p">}.</span><span class="nx">bind</span><span class="p">(</span><span class="k">this</span><span class="p">)</span>
|
||
</span><span class="hll"> <span class="p">});</span>
|
||
</span> <span class="p">},</span>
|
||
<span class="nx">getInitialState</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">{</span><span class="nx">data</span><span class="o">:</span> <span class="p">[]};</span>
|
||
<span class="p">},</span>
|
||
<span class="nx">componentDidMount</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">this</span><span class="p">.</span><span class="nx">loadCommentsFromServer</span><span class="p">();</span>
|
||
<span class="nx">setInterval</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">loadCommentsFromServer</span><span class="p">,</span> <span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">pollInterval</span><span class="p">);</span>
|
||
<span class="p">},</span>
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">div</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentBox"</span><span class="o">></span>
|
||
<span class="o"><</span><span class="nx">h1</span><span class="o">></span><span class="nx">Comments</span><span class="o"><</span><span class="err">/h1></span>
|
||
<span class="o"><</span><span class="nx">CommentList</span> <span class="nx">data</span><span class="o">=</span><span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">state</span><span class="p">.</span><span class="nx">data</span><span class="p">}</span> <span class="o">/></span>
|
||
<span class="o"><</span><span class="nx">CommentForm</span> <span class="nx">onCommentSubmit</span><span class="o">=</span><span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">handleCommentSubmit</span><span class="p">}</span> <span class="o">/></span>
|
||
<span class="o"><</span><span class="err">/div></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
</code></pre></div><h3><a class="anchor" name="-"></a>优化: 优化的更新 <a class="hash-link" href="#-">#</a></h3>
|
||
<p>我们的应用现在已经功能完备，但是它感觉很慢，因为在评论出现在列表前必须等待请求完成。我们可以优化添加这条评论到列表以使应用感觉更快。</p>
|
||
<div class="highlight"><pre><code class="language-javascript" data-lang="javascript"><span class="c1">// tutorial20.js</span>
|
||
<span class="kd">var</span> <span class="nx">CommentBox</span> <span class="o">=</span> <span class="nx">React</span><span class="p">.</span><span class="nx">createClass</span><span class="p">({</span>
|
||
<span class="nx">loadCommentsFromServer</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="nx">$</span><span class="p">.</span><span class="nx">ajax</span><span class="p">({</span>
|
||
<span class="nx">url</span><span class="o">:</span> <span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">url</span><span class="p">,</span>
|
||
<span class="nx">dataType</span><span class="o">:</span> <span class="s1">'json'</span><span class="p">,</span>
|
||
<span class="nx">cache</span><span class="o">:</span> <span class="kc">false</span><span class="p">,</span>
|
||
<span class="nx">success</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">data</span><span class="p">)</span> <span class="p">{</span>
|
||
<span class="k">this</span><span class="p">.</span><span class="nx">setState</span><span class="p">({</span><span class="nx">data</span><span class="o">:</span> <span class="nx">data</span><span class="p">});</span>
|
||
<span class="p">}.</span><span class="nx">bind</span><span class="p">(</span><span class="k">this</span><span class="p">),</span>
|
||
<span class="nx">error</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">xhr</span><span class="p">,</span> <span class="nx">status</span><span class="p">,</span> <span class="nx">err</span><span class="p">)</span> <span class="p">{</span>
|
||
<span class="nx">console</span><span class="p">.</span><span class="nx">error</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">url</span><span class="p">,</span> <span class="nx">status</span><span class="p">,</span> <span class="nx">err</span><span class="p">.</span><span class="nx">toString</span><span class="p">());</span>
|
||
<span class="p">}.</span><span class="nx">bind</span><span class="p">(</span><span class="k">this</span><span class="p">)</span>
|
||
<span class="p">});</span>
|
||
<span class="p">},</span>
|
||
<span class="nx">handleCommentSubmit</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">comment</span><span class="p">)</span> <span class="p">{</span>
|
||
<span class="hll"> <span class="kd">var</span> <span class="nx">comments</span> <span class="o">=</span> <span class="k">this</span><span class="p">.</span><span class="nx">state</span><span class="p">.</span><span class="nx">data</span><span class="p">;</span>
|
||
</span><span class="hll"> <span class="kd">var</span> <span class="nx">newComments</span> <span class="o">=</span> <span class="nx">comments</span><span class="p">.</span><span class="nx">concat</span><span class="p">([</span><span class="nx">comment</span><span class="p">]);</span>
|
||
</span><span class="hll"> <span class="k">this</span><span class="p">.</span><span class="nx">setState</span><span class="p">({</span><span class="nx">data</span><span class="o">:</span> <span class="nx">newComments</span><span class="p">});</span>
|
||
</span> <span class="nx">$</span><span class="p">.</span><span class="nx">ajax</span><span class="p">({</span>
|
||
<span class="nx">url</span><span class="o">:</span> <span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">url</span><span class="p">,</span>
|
||
<span class="nx">dataType</span><span class="o">:</span> <span class="s1">'json'</span><span class="p">,</span>
|
||
<span class="nx">type</span><span class="o">:</span> <span class="s1">'POST'</span><span class="p">,</span>
|
||
<span class="nx">data</span><span class="o">:</span> <span class="nx">comment</span><span class="p">,</span>
|
||
<span class="nx">success</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">data</span><span class="p">)</span> <span class="p">{</span>
|
||
<span class="k">this</span><span class="p">.</span><span class="nx">setState</span><span class="p">({</span><span class="nx">data</span><span class="o">:</span> <span class="nx">data</span><span class="p">});</span>
|
||
<span class="p">}.</span><span class="nx">bind</span><span class="p">(</span><span class="k">this</span><span class="p">),</span>
|
||
<span class="nx">error</span><span class="o">:</span> <span class="kd">function</span><span class="p">(</span><span class="nx">xhr</span><span class="p">,</span> <span class="nx">status</span><span class="p">,</span> <span class="nx">err</span><span class="p">)</span> <span class="p">{</span>
|
||
<span class="hll"> <span class="k">this</span><span class="p">.</span><span class="nx">setState</span><span class="p">({</span><span class="nx">data</span><span class="o">:</span> <span class="nx">comments</span><span class="p">});</span>
|
||
</span> <span class="nx">console</span><span class="p">.</span><span class="nx">error</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">url</span><span class="p">,</span> <span class="nx">status</span><span class="p">,</span> <span class="nx">err</span><span class="p">.</span><span class="nx">toString</span><span class="p">());</span>
|
||
<span class="p">}.</span><span class="nx">bind</span><span class="p">(</span><span class="k">this</span><span class="p">)</span>
|
||
<span class="p">});</span>
|
||
<span class="p">},</span>
|
||
<span class="nx">getInitialState</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">{</span><span class="nx">data</span><span class="o">:</span> <span class="p">[]};</span>
|
||
<span class="p">},</span>
|
||
<span class="nx">componentDidMount</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">this</span><span class="p">.</span><span class="nx">loadCommentsFromServer</span><span class="p">();</span>
|
||
<span class="nx">setInterval</span><span class="p">(</span><span class="k">this</span><span class="p">.</span><span class="nx">loadCommentsFromServer</span><span class="p">,</span> <span class="k">this</span><span class="p">.</span><span class="nx">props</span><span class="p">.</span><span class="nx">pollInterval</span><span class="p">);</span>
|
||
<span class="p">},</span>
|
||
<span class="nx">render</span><span class="o">:</span> <span class="kd">function</span><span class="p">()</span> <span class="p">{</span>
|
||
<span class="k">return</span> <span class="p">(</span>
|
||
<span class="o"><</span><span class="nx">div</span> <span class="nx">className</span><span class="o">=</span><span class="s2">"commentBox"</span><span class="o">></span>
|
||
<span class="o"><</span><span class="nx">h1</span><span class="o">></span><span class="nx">Comments</span><span class="o"><</span><span class="err">/h1></span>
|
||
<span class="o"><</span><span class="nx">CommentList</span> <span class="nx">data</span><span class="o">=</span><span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">state</span><span class="p">.</span><span class="nx">data</span><span class="p">}</span> <span class="o">/></span>
|
||
<span class="o"><</span><span class="nx">CommentForm</span> <span class="nx">onCommentSubmit</span><span class="o">=</span><span class="p">{</span><span class="k">this</span><span class="p">.</span><span class="nx">handleCommentSubmit</span><span class="p">}</span> <span class="o">/></span>
|
||
<span class="o"><</span><span class="err">/div></span>
|
||
<span class="p">);</span>
|
||
<span class="p">}</span>
|
||
<span class="p">});</span>
|
||
</code></pre></div><h3><a class="anchor" name=""></a>祝贺! <a class="hash-link" href="#">#</a></h3>
|
||
<p>你刚刚通过几个简单的步骤建立了一个评论框。学习更多关于<a href="/react/docs/why-react-zh-CN.html">为什么使用 React</a>, 或者深入 <a href="/react/docs/top-level-api.html">API 参考</a> 开始钻研！祝你好运！</p>
|
||
|
||
|
||
<div class="docs-prevnext">
|
||
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||
<a class="docs-prev" href="/react/docs/getting-started-zh-CN.html">← Prev</a>
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|
||
<a class="docs-next" href="/react/docs/thinking-in-react-zh-CN.html">Next →</a>
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|
||
|
||
<footer class="wrap">
|
||
<div class="left">
|
||
A Facebook & Instagram collaboration.<br>
|
||
<a href="/react/acknowledgements.html">Acknowledgements</a>
|
||
</div>
|
||
<div class="right">
|
||
© 2013–2016 Facebook Inc.<br>
|
||
Documentation licensed under <a href="https://creativecommons.org/licenses/by/4.0/">CC BY 4.0</a>.
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