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Vjeux ee5805da65 Christopher Chedeau vjeux Document isMounted … 30e16e4
Nick Thompson	nick-thompson	Clarify componentWillMount behavior	542f20b
Cheng Lou	chenglou	docs fix back link in Examples	6b15ad5
Cheng Lou	chenglou	docs add jsx->js tab to live editors	7ac5f3c
Paul O’Shannessy	zpao	Normalize line endings	6b1c6be
Ben Alpert	spicyj	Update homepage for new JSX/JS editor	761e1c8
Ben Alpert	spicyj	Properly clear live editor on JSX compile failure	d3fc5ad
Ben Alpert	spicyj	Simplify live editor execution logic	c7f0663
Cheng Lou	chenglou	[docs] Tweak frontpage first example and jsx-compiler example	8c8841c
Christoph Pojer	cpojer	Update propTypes documentation.	b66fbde
Jean Lauliac	jeanlauliac	Update broken link in 'why react' article	341d292
Jean Lauliac	jeanlauliac	Normalize internal links in 'why react' article	0681d13
aymanosman	aymanosman	Fix typo	09650e1
Bob Eagan	bobeagan	fix incorrect link	2edb76f
Bob Eagan	bobeagan	add hash link for lifecycle section of working with the browser page	3db3460
Pete Hunt	petehunt	remove references to react-page	3120192
Ben Alpert	spicyj	Fix docs typo	6e4ddfd
Paul O’Shannessy	zpao	Fix animation example code …	dd66223
Eric Schoffstall	Contra	fix grammar mistake	64ac427
Kunal Mehta	kmeht	Add documentation about React.renderComponent …	f970453
Christopher Chedeau	vjeux	s/Mock DOM/Virtual DOM/ …	22772c9
Ben Alpert	spicyj	Disable CodeMirror smart indentation …	571d173
Ben Alpert	spicyj	[docs] Fix comma splice	3810c83
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<h1>Component API</h1>
<div class="subHeader"></div>
<h2><a class="anchor" name="reactcomponent"></a>ReactComponent <a class="hash-link" href="#reactcomponent">#</a></h2>
<p>Component classes created by <code>createClass()</code> return instances of <code>ReactComponent</code> when called. Most of the time when you&#39;re using React you&#39;re either creating or consuming these component objects.</p>
<h3><a class="anchor" name="getdomnode"></a>getDOMNode <a class="hash-link" href="#getdomnode">#</a></h3><div class="highlight"><pre><code class="javascript language-javascript" data-lang="javascript"><span class="nx">DOMElement</span> <span class="nx">getDOMNode</span><span class="p">()</span>
</code></pre></div>
<p>If this component has been mounted into the DOM, this returns the corresponding native browser DOM element. This method is useful for reading values out of the DOM, such as form field values and performing DOM measurements.</p>
<h3><a class="anchor" name="setprops"></a>setProps <a class="hash-link" href="#setprops">#</a></h3><div class="highlight"><pre><code class="javascript language-javascript" data-lang="javascript"><span class="nx">setProps</span><span class="p">(</span><span class="nx">object</span> <span class="nx">nextProps</span><span class="p">)</span>
</code></pre></div>
<p>When you&#39;re integrating with an external JavaScript application you may want to signal a change to a React component rendered with <code>renderComponent()</code>. Simply call <code>setProps()</code> to change its properties and trigger a re-render.</p>
<blockquote>
<p>Note:</p>
<p>This method can only be called on a root-level component. That is, it&#39;s only available on the component passed directly to <code>renderComponent()</code> and none of its children. If you&#39;re inclined to use <code>setProps()</code> on a child component, instead take advantage of reactive updates and pass the new prop to the child component when it&#39;s created in <code>render()</code>.</p>
</blockquote>
<h3><a class="anchor" name="replaceprops"></a>replaceProps <a class="hash-link" href="#replaceprops">#</a></h3><div class="highlight"><pre><code class="javascript language-javascript" data-lang="javascript"><span class="nx">replaceProps</span><span class="p">(</span><span class="nx">object</span> <span class="nx">nextProps</span><span class="p">)</span>
</code></pre></div>
<p>Like <code>setProps()</code> but deletes any pre-existing props instead of merging the two objects.</p>
<h3><a class="anchor" name="transferpropsto"></a>transferPropsTo <a class="hash-link" href="#transferpropsto">#</a></h3><div class="highlight"><pre><code class="javascript language-javascript" data-lang="javascript"><span class="nx">ReactComponent</span> <span class="nx">transferPropsTo</span><span class="p">(</span><span class="nx">ReactComponent</span> <span class="nx">targetComponent</span><span class="p">)</span>
</code></pre></div>
<p>Transfer properties from this component to a target component that have not already been set on the target component. After the props are updated, <code>targetComponent</code> is returned as a convenience. This function is useful when creating simple HTML-like components:</p>
<div class="highlight"><pre><code class="javascript language-javascript" data-lang="javascript"><span class="kd">var</span> <span class="nx">Avatar</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="k">this</span><span class="p">.</span><span class="nx">transferPropsTo</span><span class="p">(</span>
<span class="o">&lt;</span><span class="nx">img</span> <span class="nx">src</span><span class="o">=</span><span class="p">{</span><span class="s2">&quot;/avatars/&quot;</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">userId</span> <span class="o">+</span> <span class="s2">&quot;.png&quot;</span><span class="p">}</span> <span class="nx">userId</span><span class="o">=</span><span class="p">{</span><span class="kc">null</span><span class="p">}</span> <span class="o">/&gt;</span>
<span class="p">);</span>
<span class="p">}</span>
<span class="p">});</span>
<span class="c1">// &lt;Avatar userId={17} width={200} height={200} /&gt;</span>
</code></pre></div>
<p>Properties that are specified directly on the target component instance (such as <code>src</code> and <code>userId</code> in the above example) will not be overwritten by <code>transferPropsTo</code>.</p>
<blockquote>
<p>Note:</p>
<p>Use <code>transferPropsTo</code> with caution; it encourages tight coupling and makes it easy to accidentally introduce implicit dependencies between components. When in doubt, it&#39;s safer to explicitly copy the properties that you need onto the child component.</p>
</blockquote>
<h3><a class="anchor" name="setstate"></a>setState <a class="hash-link" href="#setstate">#</a></h3><div class="highlight"><pre><code class="javascript language-javascript" data-lang="javascript"><span class="nx">setState</span><span class="p">(</span><span class="nx">object</span> <span class="nx">nextState</span><span class="p">[,</span> <span class="kd">function</span> <span class="nx">callback</span><span class="p">])</span>
</code></pre></div>
<p>Merges nextState with the current state. This is the primary method you use to trigger UI updates from event handlers and server request callbacks. In addition, you can supply an optional callback function that is executed once <code>setState</code> is completed.</p>
<blockquote>
<p>Notes:</p>
<p><em>NEVER</em> mutate <code>this.state</code> directly, as calling <code>setState()</code> afterwards may replace the mutation you made. Treat <code>this.state</code> as if it were immutable.</p>
<p><code>setState()</code> does not immediately mutate <code>this.state</code> but creates a pending state transition. Accessing <code>this.state</code> after calling this method can potentially return the existing value.</p>
<p>There is no guarantee of synchronous operation of calls to <code>setState</code> and calls may be batched for performance gains.</p>
</blockquote>
<h3><a class="anchor" name="replacestate"></a>replaceState <a class="hash-link" href="#replacestate">#</a></h3><div class="highlight"><pre><code class="javascript language-javascript" data-lang="javascript"><span class="nx">replaceState</span><span class="p">(</span><span class="nx">object</span> <span class="nx">nextState</span><span class="p">[,</span> <span class="kd">function</span> <span class="nx">callback</span><span class="p">])</span>
</code></pre></div>
<p>Like <code>setState()</code> but deletes any pre-existing state keys that are not in nextState.</p>
<h3><a class="anchor" name="forceupdate"></a>forceUpdate() <a class="hash-link" href="#forceupdate">#</a></h3><div class="highlight"><pre><code class="javascript language-javascript" data-lang="javascript"><span class="nx">forceUpdate</span><span class="p">([</span><span class="kd">function</span> <span class="nx">callback</span><span class="p">])</span>
</code></pre></div>
<p>If your <code>render()</code> method reads from something other than <code>this.props</code> or <code>this.state</code>, you&#39;ll need to tell React when it needs to re-run <code>render()</code> by calling <code>forceUpdate()</code>. You&#39;ll also need to call <code>forceUpdate()</code> if you mutate <code>this.state</code> directly.</p>
<p>Calling <code>forceUpdate()</code> will cause <code>render()</code> to be called on the component and its children, but React will still only update the DOM if the markup changes.</p>
<p>Normally you should try to avoid all uses of <code>forceUpdate()</code> and only read from <code>this.props</code> and <code>this.state</code> in <code>render()</code>. This makes your application much simpler and more efficient.</p>
<h3><a class="anchor" name="ismounted"></a>isMounted() <a class="hash-link" href="#ismounted">#</a></h3><div class="highlight"><pre><code class="javascript language-javascript" data-lang="javascript"><span class="nx">bool</span> <span class="nx">isMounted</span><span class="p">()</span>
</code></pre></div>
<p><code>isMounted()</code> returns true if the component is rendered into the DOM, false otherwise. You can use this method to guard asynchronous calls to <code>setState()</code> or <code>forceUpdate()</code>.</p>
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