The library for web and native user interfaces.
Write Default Props section
Paul O’Shannessy committed
Jul 17, 2013 at 09:12 UTC
35f092afef1d587cf3d272998f31a925b3d079e9
1 file changed
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docs/docs/05-reusable-components.md
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@@ -17,6 +17,24 @@ As your app grows it's helpful to ensure that your components are used correctly
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** TODO zpao **
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+## Default Prop Values
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+React let's you define default values for your `props` in a very declarative way:
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+
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+```javascript
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+var ComponentWithDefaultProps = React.createClass({
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+ getDefaultProps: function() {
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+ return {
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+ value: 'default value'
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+ };
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+ }
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+ /* ... */
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+});
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+```
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+
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+The result of `getDefaultProps()` will be cached and used to ensure that `this.props.value` will have a value if it was not specified by the parent component`. This allows you to safely just use your props without having to write repetitive and fragile code to handle that yourself.
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## Transferring Props: A Shortcut
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A common type of React component is one that extends a basic HTML in a simple way. Often you'll want to copy any HTML attributes passed to your component to the underlying HTML element to save typing. React provides `transferPropsTo()` to do just this.