css-layout already has a concept of start and end for the layout. In the Left-to-Right (LTR) layout, start means left, and end means right. But in RTL, start means right, and end means left. This means we can make RN depend on the start and end calculation to compute the correct layout, which includes position, padding, and margin.
In addition, css-layout already makes each component's direction inherits from its parent. This means, we simply need to set the direction of the root component to RTL, and the entire app will flip.
The diagram below describes the changes at high level:
These include:
left and right to start and end in RN core implementation for shadow nodesWith this update, when you allow RTL layout for your app:
To support RTL, you should first add the RTL language bundles to your app.
Allow RTL layout for your app by calling the allowRTL() function at the beginning of native code. We provided this utility to only apply to an RTL layout when your app is ready. Here is an example:
iOS:
Android:
For Android, you need add android:supportsRtl="true" to the <application> element in AndroidManifest.xml file.
Now, when you recompile your app and change the device language to an RTL language (e.g. Arabic or Hebrew), your app layout should change to RTL automatically.
In general, most components are already RTL-ready, for example:
Left-to-Right Layout
+ sharedI18nUtilInstance.allowRTL(context, true);
For Android, you need add android:supportsRtl="true" to the <application> element in AndroidManifest.xml file.
Now, when you recompile your app and change the device language to an RTL language (e.g. Arabic or Hebrew), your app layout should change to RTL automatically.
In general, most components are already RTL-ready, for example:
Left-to-Right Layout
Right-to-Left Layout
diff --git a/releases/next/docs/actionsheetios.html b/releases/next/docs/actionsheetios.html index 2cf427f25f2..ef9dc252042 100644 --- a/releases/next/docs/actionsheetios.html +++ b/releases/next/docs/actionsheetios.html @@ -1,6 +1,13 @@
Display an iOS action sheet. The options object must contain one or more
of:
React Nativeoptions (array of strings) - a list of button titles (required)cancelButtonIndex (int) - index of cancel button in optionsdestructiveButtonIndex (int) - index of destructive button in optionstitle (string) - a title to show above the action sheetmessage (string) - a message to show below the titleThe 'callback' function takes one parameter, the zero-based index -of the selected item.
Display the iOS share sheet. The options object should contain
+of the selected item.
Minimal example:
Display the iOS share sheet. The options object should contain
one or both of message and url and can additionally have
a subject or excludedActivityTypes:
url (string) - a URL to sharemessage (string) - a message to sharesubject (string) - a subject for the messageexcludedActivityTypes (array) - the activities to exclude from the ActionSheetNOTE: if url points to a local file, or is a base64-encoded
uri, the file it points to will be loaded and shared directly.
diff --git a/releases/next/docs/checkbox.html b/releases/next/docs/checkbox.html
index 9480828305d..0742196305a 100644
--- a/releases/next/docs/checkbox.html
+++ b/releases/next/docs/checkbox.html
@@ -1,10 +1,10 @@
-
Renders a boolean input.
This is a controlled component that requires an onValueChange callback that
+
Renders a boolean input (Android only).
This is a controlled component that requires an onValueChange callback that
updates the value prop in order for the component to reflect user actions.
If the value prop is not updated, the component will continue to render
the supplied value prop instead of the expected result of any user actions.
@keyword checkbox @keyword toggle
If true the user won't be able to toggle the checkbox. Default value is false.
Used in case the props change removes the component.
Invoked with the new value when the value changes.
Used to locate this view in end-to-end tests.
The value of the checkbox. If true the checkbox will be turned on. -Default value is false.
Improve this page by sending a pull request!
React Native supports a few keyboard shortcuts in the iOS Simulator. They are described below. To enable them, open the Hardware menu, select Keyboard, and make sure that "Connect Hardware Keyboard" is checked.
You can access the developer menu by shaking your device or by selecting "Shake Gesture" inside the Hardware menu in the iOS Simulator. You can also use the ⌘D keyboard shortcut when your app is running in the iOS Simulator, or ⌘M when running in an Android emulator.
The Developer Menu is disabled in release (production) builds.
Instead of recompiling your app every time you make a change, you can reload your app's JavaScript code instantly. To do so, select "Reload" from the Developer Menu. You can also press ⌘R in the iOS Simulator, or tap R twice on Android emulators.
You can speed up your development times by having your app reload automatically any time your code changes. Automatic reloading can be enabled by selecting "Enable Live Reload" from the Developer Menu.
You may even go a step further and keep your app running as new versions of your files are injected into the JavaScript bundle automatically by enabling Hot Reloading from the Developer Menu. This will allow you to persist the app's state through reloads.
There are some instances where hot reloading cannot be implemented perfectly. If you run into any issues, use a full reload to reset your app.
You will need to rebuild your app for changes to take effect in certain situations:
Images.xcassets on iOS or the res/drawable folder on Android.Errors and warnings are displayed inside your app in development builds.
In-app errors are displayed in a full screen alert with a red background inside your app. This screen is known as a RedBox. You can use console.error() to manually trigger one.
Warnings will be displayed on screen with a yellow background. These alerts are known as YellowBoxes. Click on the alerts to show more information or to dismiss them.
As with a RedBox, you can use console.warn() to trigger a YellowBox.
YellowBoxes can be disabled during development by using console.disableYellowBox = true;. Specific warnings can be ignored programmatically by setting an array of prefixes that should be ignored: console.ignoredYellowBox = ['Warning: ...'];.
In CI/Xcode, YellowBoxes can also be disabled by setting the IS_TESTING environment variable.
RedBoxes and YellowBoxes are automatically disabled in release (production) builds.
To debug the JavaScript code in Chrome, select "Debug JS Remotely" from the Developer Menu. This will open a new tab at http://localhost:8081/debugger-ui.
Select Tools → Developer Tools from the Chrome Menu to open the Developer Tools. You may also access the DevTools using keyboard shortcuts (⌘⌥I on macOS, Ctrl Shift I on Windows). You may also want to enable Pause On Caught Exceptions for a better debugging experience.
Note: the React Developer Tools Chrome extension does not work with React Native, but you can use its standalone version instead. Read this section to learn how.
To use a custom JavaScript debugger in place of Chrome Developer Tools, set the REACT_DEBUGGER environment variable to a command that will start your custom debugger. You can then select "Debug JS Remotely" from the Developer Menu to start debugging.
The debugger will receive a list of all project roots, separated by a space. For example, if you set REACT_DEBUGGER="node /path/to/launchDebugger.js --port 2345 --type ReactNative", then the command node /path/to/launchDebugger.js --port 2345 --type ReactNative /path/to/reactNative/app will be used to start your debugger.
Custom debugger commands executed this way should be short-lived processes, and they shouldn't produce more than 200 kilobytes of output.
You can use the standalone version of React Developer Tools to debug the React component hierarchy. To use it, install the react-devtools package globally:
Now run react-devtools from the terminal to launch the standalone DevTools app:
It should connect to your simulator within a few seconds.
Note: if you prefer to avoid global installations, you can add
react-devtoolsas a project dependency. Add thereact-devtoolspackage to your project usingnpm install --save-dev react-devtools, then add"react-devtools": "react-devtools"to thescriptssection in yourpackage.json, and then runnpm run react-devtoolsfrom your project folder to open the DevTools.
Open the in-app developer menu and choose "Show Inspector". It will bring up an overlay that lets you tap on any UI element and see information about it:
However, when react-devtools is running, Inspector will enter a special collapsed mode, and instead use the DevTools as primary UI. In this mode, clicking on something in the simulator will bring up the relevant components in the DevTools:
You can choose "Hide Inspector" in the same menu to exit this mode.
When debugging JavaScript in Chrome, you can inspect the props and state of the React components in the browser console.
First, follow the instructions for debugging in Chrome to open the Chrome console.
Make sure that the dropdown in the top left corner of the Chrome console says debuggerWorker.js. This step is essential.
Then select a React component in React DevTools. There is a search box at the top that helps you find one by name. As soon as you select it, it will be available as $r in the Chrome console, letting you inspect its props, state, and instance properties.
You can enable a performance overlay to help you debug performance problems by selecting "Perf Monitor" in the Developer Menu.
React Native supports a few keyboard shortcuts in the iOS Simulator. They are described below. To enable them, open the Hardware menu, select Keyboard, and make sure that "Connect Hardware Keyboard" is checked.
You can access the developer menu by shaking your device or by selecting "Shake Gesture" inside the Hardware menu in the iOS Simulator. You can also use the ⌘D keyboard shortcut when your app is running in the iOS Simulator, or ⌘M when running in an Android emulator. Alternatively for Android, you can run the command adb shell input keyevent 82 to open the dev menu (82 being the Menu key code).
The Developer Menu is disabled in release (production) builds.
Instead of recompiling your app every time you make a change, you can reload your app's JavaScript code instantly. To do so, select "Reload" from the Developer Menu. You can also press ⌘R in the iOS Simulator, or tap R twice on Android emulators.
You can speed up your development times by having your app reload automatically any time your code changes. Automatic reloading can be enabled by selecting "Enable Live Reload" from the Developer Menu.
You may even go a step further and keep your app running as new versions of your files are injected into the JavaScript bundle automatically by enabling Hot Reloading from the Developer Menu. This will allow you to persist the app's state through reloads.
There are some instances where hot reloading cannot be implemented perfectly. If you run into any issues, use a full reload to reset your app.
You will need to rebuild your app for changes to take effect in certain situations:
Images.xcassets on iOS or the res/drawable folder on Android.Errors and warnings are displayed inside your app in development builds.
In-app errors are displayed in a full screen alert with a red background inside your app. This screen is known as a RedBox. You can use console.error() to manually trigger one.
Warnings will be displayed on screen with a yellow background. These alerts are known as YellowBoxes. Click on the alerts to show more information or to dismiss them.
As with a RedBox, you can use console.warn() to trigger a YellowBox.
YellowBoxes can be disabled during development by using console.disableYellowBox = true;. Specific warnings can be ignored programmatically by setting an array of prefixes that should be ignored: console.ignoredYellowBox = ['Warning: ...'];.
In CI/Xcode, YellowBoxes can also be disabled by setting the IS_TESTING environment variable.
RedBoxes and YellowBoxes are automatically disabled in release (production) builds.
To debug the JavaScript code in Chrome, select "Debug JS Remotely" from the Developer Menu. This will open a new tab at http://localhost:8081/debugger-ui.
Select Tools → Developer Tools from the Chrome Menu to open the Developer Tools. You may also access the DevTools using keyboard shortcuts (⌘⌥I on macOS, Ctrl Shift I on Windows). You may also want to enable Pause On Caught Exceptions for a better debugging experience.
Note: the React Developer Tools Chrome extension does not work with React Native, but you can use its standalone version instead. Read this section to learn how.
To use a custom JavaScript debugger in place of Chrome Developer Tools, set the REACT_DEBUGGER environment variable to a command that will start your custom debugger. You can then select "Debug JS Remotely" from the Developer Menu to start debugging.
The debugger will receive a list of all project roots, separated by a space. For example, if you set REACT_DEBUGGER="node /path/to/launchDebugger.js --port 2345 --type ReactNative", then the command node /path/to/launchDebugger.js --port 2345 --type ReactNative /path/to/reactNative/app will be used to start your debugger.
Custom debugger commands executed this way should be short-lived processes, and they shouldn't produce more than 200 kilobytes of output.
You can use the standalone version of React Developer Tools to debug the React component hierarchy. To use it, install the react-devtools package globally:
Now run react-devtools from the terminal to launch the standalone DevTools app:
It should connect to your simulator within a few seconds.
Note: if you prefer to avoid global installations, you can add
react-devtoolsas a project dependency. Add thereact-devtoolspackage to your project usingnpm install --save-dev react-devtools, then add"react-devtools": "react-devtools"to thescriptssection in yourpackage.json, and then runnpm run react-devtoolsfrom your project folder to open the DevTools.
Open the in-app developer menu and choose "Show Inspector". It will bring up an overlay that lets you tap on any UI element and see information about it:
However, when react-devtools is running, Inspector will enter a special collapsed mode, and instead use the DevTools as primary UI. In this mode, clicking on something in the simulator will bring up the relevant components in the DevTools:
You can choose "Hide Inspector" in the same menu to exit this mode.
When debugging JavaScript in Chrome, you can inspect the props and state of the React components in the browser console.
First, follow the instructions for debugging in Chrome to open the Chrome console.
Make sure that the dropdown in the top left corner of the Chrome console says debuggerWorker.js. This step is essential.
Then select a React component in React DevTools. There is a search box at the top that helps you find one by name. As soon as you select it, it will be available as $r in the Chrome console, letting you inspect its props, state, and instance properties.
You can enable a performance overlay to help you debug performance problems by selecting "Perf Monitor" in the Developer Menu.
A sinusoidal function.
A circular function.
An exponential function.
A simple elastic interaction, similar to a spring oscillating back and forth.
Default bounciness is 1, which overshoots a little bit once. 0 bounciness doesn't overshoot at all, and bounciness of N > 1 will overshoot about N -times.
http://easings.net/#easeInElastic
Wolfram Plots:
Use with Animated.parallel() to create a simple effect where the object
+times.
Use with Animated.parallel() to create a simple effect where the object
animates back slightly as the animation starts.
Wolfram Plot:
Provides a simple bouncing effect.
Provides a cubic bezier curve, equivalent to CSS Transitions'
transition-timing-function.
A useful tool to visualize cubic bezier curves can be found at http://cubic-bezier.com/
Runs an easing function forwards.
Runs an easing function backwards.
Makes any easing function symmetrical. The easing function will run diff --git a/releases/next/docs/flexbox.html b/releases/next/docs/flexbox.html index b7b8b64272a..282e8056ad3 100644 --- a/releases/next/docs/flexbox.html +++ b/releases/next/docs/flexbox.html @@ -37,7 +37,7 @@ }; // skip this line if using Create React Native App -AppRegistry.registerComponent('AwesomeProject', () => JustifyContentBasics);
Adding alignItems to a component's style determines the alignment of children along the secondary axis (if the primary axis is row, then the secondary is column, and vice versa). Should children be aligned at the start, the center, the end, or stretched to fill? Available options are flex-start, center, flex-end, and stretch.
For
stretchto have an effect, children must not have a fixed dimension along the secondary axis. In the following example, settingalignItems: stretchdoes nothing until thewidth: 50is removed from the children.
Adding alignItems to a component's style determines the alignment of children along the secondary axis (if the primary axis is row, then the secondary is column, and vice versa). Should children be aligned at the start, the center, the end, or stretched to fill? Available options are flex-start, center, flex-end, and stretch.
For
stretchto have an effect, children must not have a fixed dimension along the secondary axis. In the following example, settingalignItems: stretchdoes nothing until theheight: 50is removed from the children.
If you just read through this website, you should be able to build a pretty cool React Native app. But React Native isn't just a product made by one company - it's a community of thousands of developers. So if you're interested in React Native, here's some related stuff you might want to check out.
If you're using React Native, you probably already know about React. So I feel a bit silly mentioning this. But if you haven't, check out React - it's the best way to build a modern website.
One common question is how to handle the "state" of your React Native application. The most popular library for this is Redux. Don't be afraid of how often Redux uses the word "reducer" - it's a pretty simple library, and there's also a nice series of videos explaining it.
If you're looking for a library that does a specific thing, check out Awesome React Native, a curated list of components that also has demos, articles, and other stuff.
Try out apps from the Showcase to see what React Native is capable of! There are also some example apps on GitHub. You can run the apps on a simulator or device, and you can see the source code for these apps, which is neat.
The folks who built the app for Facebook's F8 conference in 2016 also open-sourced the code and wrote up a detailed series of tutorials. This is useful if you want a more in-depth example that's more realistic than most sample apps out there.
Nuclide is the IDE that Facebook uses internally for JavaScript development. The killer feature of Nuclide is its debugging ability. It also has great inline Flow support. VS Code is another IDE that is popular with JavaScript developers.
Ignite is a starter kit that uses Redux and a few different common UI libraries. It has a CLI to generate apps, components, and containers. If you like all of the individual tech choices, Ignite could be perfect for you.
CodePush is a service from Microsoft that makes it easy to deploy live updates to your React Native app. If you don't like going through the app store process to deploy little tweaks, and you also don't like setting up your own backend, give CodePush a try.
Expo is a development environment plus application that focuses on letting you build React Native apps in the Expo development environment, without ever touching Xcode or Android Studio. If you wish React Native was even more JavaScripty and webby, check out Expo.
The React Developer Tools are great for debugging React and React Native apps.
The React Native Community Facebook group has thousands of developers, and it's pretty active. Come there to show off your project, or ask how other people solved similar problems.
Reactiflux is a Discord chat where a lot of React-related discussion happens, including React Native. Discord is just like Slack except it works better for open source projects with a zillion contributors. Check out the #react-native channel.
The React Twitter account covers both React and React Native. Follow the React Native Twitter account and blog to find out what's happening in the world of React Native.
There are a lot of React Native Meetups that happen around the world. Often there is React Native content in React meetups as well.
Sometimes we have React conferences. We posted the videos from React.js Conf 2017 and React.js Conf 2016, and we'll probably have more conferences in the future, too. Stay tuned. You can also find a list of dedicated React Native conferences here.
Improve this page by sending a pull request!
If you just read through this website, you should be able to build a pretty cool React Native app. But React Native isn't just a product made by one company - it's a community of thousands of developers. So if you're interested in React Native, here's some related stuff you might want to check out.
If you're using React Native, you probably already know about React. So I feel a bit silly mentioning this. But if you haven't, check out React - it's the best way to build a modern website.
One common question is how to handle the "state" of your React Native application. The most popular library for this is Redux. Don't be afraid of how often Redux uses the word "reducer" - it's a pretty simple library, and there's also a nice series of videos explaining it.
If you're looking for a library that does a specific thing, check out Awesome React Native, a curated list of components that also has demos, articles, and other stuff.
Try out apps from the Showcase to see what React Native is capable of! There are also some example apps on GitHub. You can run the apps on a simulator or device, and you can see the source code for these apps, which is neat.
The folks who built the app for Facebook's F8 conference in 2016 also open-sourced the code and wrote up a detailed series of tutorials. This is useful if you want a more in-depth example that's more realistic than most sample apps out there.
Nuclide is the IDE that Facebook uses internally for JavaScript development. The killer feature of Nuclide is its debugging ability. It also has great inline Flow support. VS Code is another IDE that is popular with JavaScript developers.
Ignite is a starter kit that uses Redux and a few different common UI libraries. It has a CLI to generate apps, components, and containers. If you like all of the individual tech choices, Ignite could be perfect for you.
CodePush is a service from Microsoft that makes it easy to deploy live updates to your React Native app. If you don't like going through the app store process to deploy little tweaks, and you also don't like setting up your own backend, give CodePush a try.
Expo is a development environment plus application that focuses on letting you build React Native apps in the Expo development environment, without ever touching Xcode or Android Studio. If you wish React Native was even more JavaScripty and webby, check out Expo.
The React Developer Tools are great for debugging React and React Native apps.
The React Native Community Facebook group has thousands of developers, and it's pretty active. Come there to show off your project, or ask how other people solved similar problems.
Reactiflux is a Discord chat where a lot of React-related discussion happens, including React Native. Discord is just like Slack except it works better for open source projects with a zillion contributors. Check out the #react-native channel.
The React Twitter account covers both React and React Native. Follow the React Native Twitter account and blog to find out what's happening in the world of React Native.
There are a lot of React Native Meetups that happen around the world. Often there is React Native content in React meetups as well.
Sometimes we have React conferences. We posted the videos from React.js Conf 2017 and React.js Conf 2016, and we'll probably have more conferences in the future, too. Stay tuned. You can also find a list of dedicated React Native conferences here.
Improve this page by sending a pull request!