写在读ng之前的基础知识----笔记
如果要看angular的代码, 先把这个给看了, 司徒的干货。
/********************************************************************* * 依赖调度系统 * **********************************************************************/ var ronduplex = /^(duplex|on)$/ function registerSubscriber(data) { Registry[expose] = data //暴光此函数,方便collectSubscribers收集 avalon.openComputedCollect = true var fn = data.evaluator if (fn) { //如果是求值函数 try { var c = ronduplex.test(data.type) ? data : fn.apply(0, data.args) data.handler(c, data.element, data) } catch (e) { log("warning:exception throwed in [registerSubscriber] " + e) delete data.evaluator var node = data.element if (node.nodeType === 3) { var parent = node.parentNode if (kernel.commentInterpolate) { parent.replaceChild(DOC.createComment(data.value), node) } else { node.data = openTag + data.value + closeTag } } } } avalon.openComputedCollect = false delete Registry[expose] } function collectSubscribers(list) { //收集依赖于这个访问器的订阅者 var data = Registry[expose] if (list && data && avalon.Array.ensure(list, data) && data.element) { //只有数组不存在此元素才push进去 addSubscribers(data, list) } } function addSubscribers(data, list) { data.$uuid = data.$uuid || generateID() list.$uuid = list.$uuid || generateID() var obj = { data: data, list: list, toString: function() { return data.$uuid + " " + list.$uuid } } if (!$$subscribers[obj]) { $$subscribers[obj] = 1 $$subscribers.push(obj) } } var $$subscribers = [], $startIndex = 0, $maxIndex = 200, beginTime = new Date(), removeID function removeSubscribers() { for (var i = $startIndex, n = $startIndex + $maxIndex; i < n; i++) { var obj = $$subscribers[i] if (!obj) { break } var data = obj.data var el = data.element var remove = el === null ? 1 : (el.nodeType === 1 ? typeof el.sourceIndex === "number" ? el.sourceIndex === 0 : !root.contains(el) : !avalon.contains(root, el)) if (remove) { //如果它没有在DOM树 $$subscribers.splice(i, 1) delete $$subscribers[obj] avalon.Array.remove(obj.list, data) //log("debug: remove " + data.type) disposeData(data) obj.data = obj.list = null i-- n-- } } obj = $$subscribers[i] if (obj) { $startIndex = n } else { $startIndex = 0 } beginTime = new Date() } function disposeData(data) { data.element = null data.rollback && data.rollback() for (var key in data) { data[key] = null } } function notifySubscribers(list) { //通知依赖于这个访问器的订阅者更新自身 clearTimeout(removeID) if (new Date() - beginTime > 444) { removeSubscribers() } else { removeID = setTimeout(removeSubscribers, 444) } if (list && list.length) { var args = aslice.call(arguments, 1) for (var i = list.length, fn; fn = list[--i]; ) { var el = fn.element if (el && el.parentNode) { if (fn.$repeat) { fn.handler.apply(fn, args) //处理监控数组的方法 } else if (fn.type !== "on") { //事件绑定只能由用户触发,不能由程序触发 var fun = fn.evaluator || noop fn.handler(fun.apply(0, fn.args || []), el, fn) } } } } }
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