return _this.$methods[attrVal].bind(_this.$data); //bind是使data的作用域与method函数的作用域保持一致
})();
}
if (node.hasAttribute('v-model') && (node.tagName == 'INPUT' || node.tagName == 'TEXTAREA')) { // 如果有v-model属性，并且元素是INPUT或者TEXTAREA，我们监听它的input事件
node.addEventListener('input', (function(key) {
var attrVal = node.getAttribute('v-model');
//_this._binding['number']._directives = [一个Watcher实例] // 其中Watcher.prototype.update = function () {
// node['vaule'] = _this.$data['number']; 这就将node的值保持与number一致
// }
_this._binding[attrVal]._directives.push(new Watcher(
'input',
node,
_this,
attrVal,
'value'
))
return function() {
_this.$data[attrVal] = nodes[key].value; // 使number 的值与 node的value保持一致，已经实现了双向绑定
}
})(i));
}
if (node.hasAttribute('v-bind')) { // 如果有v-bind属性，我们只要使node的值及时更新为data中number的值即可
var attrVal = node.getAttribute('v-bind');
_this._binding[attrVal]._directives.push(new Watcher(
'text',
node,
_this,
attrVal,
'innerHTML'
))
}
}
}
至此，我们已经实现了一个简单vue的双向绑定功能，包括v-bind, v-model, v-click三个指令。效果如下图
附上全部代码，不到150行
<!DOCTYPE html>
<head>
<title>myVue</title>
</head>
<style>
#app {
text-align: center;
}
</style>
<body>
<div id="app">
<form>
<input type="text" v-model="number">
<button type="button" v-click="increment">增加</button>
</form>
<h3 v-bind="number"></h3>
</div>
</body>
<script>
function myVue(options) {
this._init(options);
}
myVue.prototype._init = function (options) {
this.$options = options;
this.$el = document.querySelector(options.el);
this.$data = options.data;
this.$methods = options.methods;
this._binding = {};
this._obverse(this.$data);
this._complie(this.$el);
}
myVue.prototype._obverse = function (obj) {
var value;
for (key in obj) {
if (obj.hasOwnProperty(key)) {
this._binding[key] = {
_directives: [] };
value = obj[key];
if (typeof value === 'object') {
this._obverse(value);
}
var binding = this._binding[key];
Object.defineProperty(this.$data, key, {
enumerable: true,
configurable: true,
get: function () {
console.log(`获取${value}`);
return value;
