react核心api和jsx

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1//ReactElement.js
2export function createElement(type, config, children) {
3  let propName;
4
5  const props = {};
6
7  let key = null;
8  let ref = null;
9  let self = null;
10  let source = null;
11
12  if (config != null) {
13    //处理config，把除了保留属性外的其他config赋值给props
14    //...
15  }
16
17  const childrenLength = arguments.length - 2;
18  //把children处理后赋值给props.children
19  //...
20
21  //处理defaultProps
22  //...
23
24  return ReactElement(
25    type,
26    key,
27    ref,
28    self,
29    source,
30    ReactCurrentOwner.current,
31    props,
32  );
33}
34
35const ReactElement = function(type, key, ref, self, source, owner, props) {
36  const element = {
37    $$typeof: REACT_ELEMENT_TYPE,//表示是ReactElement类型
38
39    type: type,//class或function
40    key: key,//key
41    ref: ref,//ref属性
42    props: props,//props
43    _owner: owner,
44  };
45
46  return element;
47};

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1//ReactElement.js
2export function isValidElement(object) {
3  return (
4    typeof object === 'object' &&
5    object !== null &&
6    object.$$typeof === REACT_ELEMENT_TYPE
7  );
8}

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1//ReactDOMLegacy.js
2export function render(
3  element: React$Element<any>,//jsx对象
4  container: Container,//挂载dom
5  callback: ?Function,//回调
6) {
7  
8  return legacyRenderSubtreeIntoContainer(
9    null,
10    element,
11    container,
12    false,
13    callback,
14  );
15}

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1//ReactBaseClasses.js
2function Component(props, context, updater) {
3  this.props = props;//props属性
4  this.context = context;//当前的context
5  this.refs = emptyObject;//ref挂载的对象
6  this.updater = updater || ReactNoopUpdateQueue;//更新的对像
7}
8
9Component.prototype.isReactComponent = {};//表示是classComponent

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1function PureComponent(props, context, updater) {
2  this.props = props;
3  this.context = context;
4  this.refs = emptyObject;
5  this.updater = updater || ReactNoopUpdateQueue;
6}
7
8const pureComponentPrototype = (PureComponent.prototype = new ComponentDummy());
9pureComponentPrototype.constructor = PureComponent;
10Object.assign(pureComponentPrototype, Component.prototype);
11pureComponentPrototype.isPureReactComponent = true;
12
13export {Component, PureComponent};