41 lines
1.4 KiB
JavaScript
41 lines
1.4 KiB
JavaScript
|
/**
|
||
|
|
* Copyright 2013-present, Facebook, Inc.
|
||
|
|
* All rights reserved.
|
||
|
|
*
|
||
|
|
* This source code is licensed under the BSD-style license found in the
|
||
|
|
* LICENSE file in the root directory of this source tree. An additional grant
|
||
|
|
* of patent rights can be found in the PATENTS file in the same directory.
|
||
|
|
*
|
||
|
|
*/
|
||
|
|
|
||
|
|
'use strict';
|
||
|
|
|
||
|
|
/**
|
||
|
|
* Given a `prevElement` and `nextElement`, determines if the existing
|
||
|
|
* instance should be updated as opposed to being destroyed or replaced by a new
|
||
|
|
* instance. Both arguments are elements. This ensures that this logic can
|
||
|
|
* operate on stateless trees without any backing instance.
|
||
|
|
*
|
||
|
|
* @param {?object} prevElement
|
||
|
|
* @param {?object} nextElement
|
||
|
|
* @return {boolean} True if the existing instance should be updated.
|
||
|
|
* @protected
|
||
|
|
*/
|
||
|
|
|
||
|
|
function shouldUpdateReactComponent(prevElement, nextElement) {
|
||
|
|
var prevEmpty = prevElement === null || prevElement === false;
|
||
|
|
var nextEmpty = nextElement === null || nextElement === false;
|
||
|
|
if (prevEmpty || nextEmpty) {
|
||
|
|
return prevEmpty === nextEmpty;
|
||
|
|
}
|
||
|
|
|
||
|
|
var prevType = typeof prevElement;
|
||
|
|
var nextType = typeof nextElement;
|
||
|
|
if (prevType === 'string' || prevType === 'number') {
|
||
|
|
return nextType === 'string' || nextType === 'number';
|
||
|
|
} else {
|
||
|
|
return nextType === 'object' && prevElement.type === nextElement.type && prevElement.key === nextElement.key;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
module.exports = shouldUpdateReactComponent;
|