Files
react/src/core/shouldUpdateReactComponent.js
T
Sebastian Markbage c40e06f728 First phase to true descriptors
This moves all convenience constructors to use frozen ReactDescriptors.
2014-03-28 12:32:53 -07:00

45 lines
1.6 KiB
JavaScript

/**
* Copyright 2013-2014 Facebook, Inc.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*
* @providesModule shouldUpdateReactComponent
* @typechecks static-only
*/
"use strict";
/**
* Given a `prevDescriptor` and `nextDescriptor`, determines if the existing
* instance should be updated as opposed to being destroyed or replaced by a new
* instance. Both arguments are descriptors. This ensures that this logic can
* operate on stateless trees without any backing instance.
*
* @param {?object} prevDescriptor
* @param {?object} nextDescriptor
* @return {boolean} True if the existing instance should be updated.
* @protected
*/
function shouldUpdateReactComponent(prevDescriptor, nextDescriptor) {
if (prevDescriptor && nextDescriptor &&
prevDescriptor.type === nextDescriptor.type && (
(prevDescriptor.props && prevDescriptor.props.key) ===
(nextDescriptor.props && nextDescriptor.props.key)
) && prevDescriptor._owner === nextDescriptor._owner) {
return true;
}
return false;
}
module.exports = shouldUpdateReactComponent;