Created
September 25, 2018 08:10
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React.createElement
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| const React = { | |
| createElement: function (tag, attrs, children) { | |
| var element = document.createElement(tag); | |
| for (let name in attrs) { | |
| if (name && attrs.hasOwnProperty(name)) { | |
| let value = attrs[name]; | |
| if (value === true) { | |
| element.setAttribute(name, name); | |
| } else if (value !== false && value != null) { | |
| element.setAttribute(name, value.toString()); | |
| } | |
| } | |
| } | |
| for (let i = 2; i < arguments.length; i++) { | |
| let child = arguments[i]; | |
| element.appendChild( | |
| child.nodeType == null ? | |
| document.createTextNode(child.toString()) : child); | |
| } | |
| return element; | |
| } | |
| }; |
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| <!doctype html> | |
| <html lang="zh-CN"> | |
| <head> | |
| <meta charset="UTF-8"> | |
| <title>react简单实现-方式2</title> | |
| </head> | |
| <body> | |
| <div id="app"></div> | |
| <script src="createElement.js"></script> | |
| <script> | |
| //args | |
| var title = "Hello World"; | |
| //event | |
| var handleClick = function(){ | |
| console.log(123) | |
| } | |
| document.querySelector('#app').appendChild(React.createElement("div", null, | |
| React.createElement("h1", {class:'qwe',onclick:"handleClick()"}, title), | |
| React.createElement("h2", null, "This is a template written in TSX, then compiled to JSX by tsc (the Typescript compiler), and finally" + " " + "injected into a web page"))); | |
| </script> | |
| </body> | |
| </html> |
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This is a simplified version of how
React.createElement()might conceptually work under the hood. The actual implementation is much more complicated with a ton of other stuff. I don't understand it myself.https://github.com/facebook/react/blob/a4195750779dbd9a13e1615fbbd493bf2c5768ca/packages/react/src/ReactElement.js#L362