40 lines
1.1 KiB
JavaScript
40 lines
1.1 KiB
JavaScript
/**
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* 设置监听器
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*/
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/**
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* 设置监听器
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*/
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function setWatcher(data, watch) {
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Object.keys(watch).forEach(v => {
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let key = v.split('.'); // 将watch中的属性以'.'切分成数组
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let nowData = data; // 将data赋值给nowData
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for (let i = 0; i < key.length - 1; i++) { // 遍历key数组的元素，除了最后一个！
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nowData = nowData[key[i]]; // 将nowData指向它的key属性对象
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}
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let lastKey = key[key.length - 1];
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// 假设key==='my.name',此时nowData===data['my']===data.my,lastKey==='name'
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observe(nowData, lastKey, watch[v]); // 监听nowData对象的lastKey
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})
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}
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/**
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* 监听属性 并执行监听函数
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*/
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function observe(obj, key, watchFun) {
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var val = obj[key]; // 给该属性设默认值
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Object.defineProperty(obj, key, {
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configurable: true,
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enumerable: true,
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set: function (value) {
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val = value;
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watchFun(value, val); // 赋值(set)时，调用对应函数
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},
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get: function () {
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return val;
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}
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})
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}
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module.exports = {
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setWatcher: setWatcher
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} |