d2-ui
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JavaScript
/**
* Copyright 2014-2015, 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.
*
* @providesModule ReactElement
*/
;
var ReactCurrentOwner = require('./ReactCurrentOwner');
var assign = require('./Object.assign');
var canDefineProperty = require('./canDefineProperty');
// The Symbol used to tag the ReactElement type. If there is no native Symbol
// nor polyfill, then a plain number is used for performance.
var REACT_ELEMENT_TYPE = typeof Symbol === 'function' && Symbol['for'] && Symbol['for']('react.element') || 0xeac7;
var RESERVED_PROPS = {
key: true,
ref: true,
__self: true,
__source: true
};
/**
* Base constructor for all React elements. This is only used to make this
* work with a dynamic instanceof check. Nothing should live on this prototype.
*
* @param {*} type
* @param {*} key
* @param {string|object} ref
* @param {*} self A *temporary* helper to detect places where `this` is
* different from the `owner` when React.createElement is called, so that we
* can warn. We want to get rid of owner and replace string `ref`s with arrow
* functions, and as long as `this` and owner are the same, there will be no
* change in behavior.
* @param {*} source An annotation object (added by a transpiler or otherwise)
* indicating filename, line number, and/or other information.
* @param {*} owner
* @param {*} props
* @internal
*/
var ReactElement = function (type, key, ref, self, source, owner, props) {
var element = {
// This tag allow us to uniquely identify this as a React Element
$$typeof: REACT_ELEMENT_TYPE,
// Built-in properties that belong on the element
type: type,
key: key,
ref: ref,
props: props,
// Record the component responsible for creating this element.
_owner: owner
};
if (process.env.NODE_ENV !== 'production') {
// The validation flag is currently mutative. We put it on
// an external backing store so that we can freeze the whole object.
// This can be replaced with a WeakMap once they are implemented in
// commonly used development environments.
element._store = {};
// To make comparing ReactElements easier for testing purposes, we make
// the validation flag non-enumerable (where possible, which should
// include every environment we run tests in), so the test framework
// ignores it.
if (canDefineProperty) {
Object.defineProperty(element._store, 'validated', {
configurable: false,
enumerable: false,
writable: true,
value: false
});
// self and source are DEV only properties.
Object.defineProperty(element, '_self', {
configurable: false,
enumerable: false,
writable: false,
value: self
});
// Two elements created in two different places should be considered
// equal for testing purposes and therefore we hide it from enumeration.
Object.defineProperty(element, '_source', {
configurable: false,
enumerable: false,
writable: false,
value: source
});
} else {
element._store.validated = false;
element._self = self;
element._source = source;
}
Object.freeze(element.props);
Object.freeze(element);
}
return element;
};
ReactElement.createElement = function (type, config, children) {
var propName;
// Reserved names are extracted
var props = {};
var key = null;
var ref = null;
var self = null;
var source = null;
if (config != null) {
ref = config.ref === undefined ? null : config.ref;
key = config.key === undefined ? null : '' + config.key;
self = config.__self === undefined ? null : config.__self;
source = config.__source === undefined ? null : config.__source;
// Remaining properties are added to a new props object
for (propName in config) {
if (config.hasOwnProperty(propName) && !RESERVED_PROPS.hasOwnProperty(propName)) {
props[propName] = config[propName];
}
}
}
// Children can be more than one argument, and those are transferred onto
// the newly allocated props object.
var childrenLength = arguments.length - 2;
if (childrenLength === 1) {
props.children = children;
} else if (childrenLength > 1) {
var childArray = Array(childrenLength);
for (var i = 0; i < childrenLength; i++) {
childArray[i] = arguments[i + 2];
}
props.children = childArray;
}
// Resolve default props
if (type && type.defaultProps) {
var defaultProps = type.defaultProps;
for (propName in defaultProps) {
if (typeof props[propName] === 'undefined') {
props[propName] = defaultProps[propName];
}
}
}
return ReactElement(type, key, ref, self, source, ReactCurrentOwner.current, props);
};
ReactElement.createFactory = function (type) {
var factory = ReactElement.createElement.bind(null, type);
// Expose the type on the factory and the prototype so that it can be
// easily accessed on elements. E.g. `<Foo />.type === Foo`.
// This should not be named `constructor` since this may not be the function
// that created the element, and it may not even be a constructor.
// Legacy hook TODO: Warn if this is accessed
factory.type = type;
return factory;
};
ReactElement.cloneAndReplaceKey = function (oldElement, newKey) {
var newElement = ReactElement(oldElement.type, newKey, oldElement.ref, oldElement._self, oldElement._source, oldElement._owner, oldElement.props);
return newElement;
};
ReactElement.cloneAndReplaceProps = function (oldElement, newProps) {
var newElement = ReactElement(oldElement.type, oldElement.key, oldElement.ref, oldElement._self, oldElement._source, oldElement._owner, newProps);
if (process.env.NODE_ENV !== 'production') {
// If the key on the original is valid, then the clone is valid
newElement._store.validated = oldElement._store.validated;
}
return newElement;
};
ReactElement.cloneElement = function (element, config, children) {
var propName;
// Original props are copied
var props = assign({}, element.props);
// Reserved names are extracted
var key = element.key;
var ref = element.ref;
// Self is preserved since the owner is preserved.
var self = element._self;
// Source is preserved since cloneElement is unlikely to be targeted by a
// transpiler, and the original source is probably a better indicator of the
// true owner.
var source = element._source;
// Owner will be preserved, unless ref is overridden
var owner = element._owner;
if (config != null) {
if (config.ref !== undefined) {
// Silently steal the ref from the parent.
ref = config.ref;
owner = ReactCurrentOwner.current;
}
if (config.key !== undefined) {
key = '' + config.key;
}
// Remaining properties override existing props
for (propName in config) {
if (config.hasOwnProperty(propName) && !RESERVED_PROPS.hasOwnProperty(propName)) {
props[propName] = config[propName];
}
}
}
// Children can be more than one argument, and those are transferred onto
// the newly allocated props object.
var childrenLength = arguments.length - 2;
if (childrenLength === 1) {
props.children = children;
} else if (childrenLength > 1) {
var childArray = Array(childrenLength);
for (var i = 0; i < childrenLength; i++) {
childArray[i] = arguments[i + 2];
}
props.children = childArray;
}
return ReactElement(element.type, key, ref, self, source, owner, props);
};
/**
* @param {?object} object
* @return {boolean} True if `object` is a valid component.
* @final
*/
ReactElement.isValidElement = function (object) {
return typeof object === 'object' && object !== null && object.$$typeof === REACT_ELEMENT_TYPE;
};
module.exports = ReactElement;