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35 lines
1.2 KiB
35 lines
1.2 KiB
/** |
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* Copyright (c) 2013-present, Facebook, Inc. |
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* |
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* This source code is licensed under the MIT license found in the |
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* LICENSE file in the root directory of this source tree. |
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* |
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*/ |
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'use strict'; |
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var _prodInvariant = require('./reactProdInvariant'); |
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var ReactElement = require('./ReactElement'); |
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var invariant = require('fbjs/lib/invariant'); |
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/** |
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* Returns the first child in a collection of children and verifies that there |
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* is only one child in the collection. |
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* |
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* See https://facebook.github.io/react/docs/top-level-api.html#react.children.only |
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* |
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* The current implementation of this function assumes that a single child gets |
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* passed without a wrapper, but the purpose of this helper function is to |
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* abstract away the particular structure of children. |
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* |
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* @param {?object} children Child collection structure. |
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* @return {ReactElement} The first and only `ReactElement` contained in the |
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* structure. |
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*/ |
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function onlyChild(children) { |
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!ReactElement.isValidElement(children) ? process.env.NODE_ENV !== 'production' ? invariant(false, 'React.Children.only expected to receive a single React element child.') : _prodInvariant('143') : void 0; |
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return children; |
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} |
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module.exports = onlyChild; |