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| 1 | +/** |
| 2 | + * @file dom-watcher.js |
| 3 | + * @author clark-t ([email protected]) |
| 4 | + */ |
| 5 | + |
| 6 | +import { isElementNode } from '../../util/dom/dom' |
| 7 | +import { |
| 8 | + traverse |
| 9 | +} from '../../util/fn' |
| 10 | + |
| 11 | +import { |
| 12 | + isBindingAttr |
| 13 | +} from './binding' |
| 14 | + |
| 15 | +class DOMWatcher { |
| 16 | + constructor () { |
| 17 | + this.doms = [] |
| 18 | + this.watchers = [] |
| 19 | + } |
| 20 | + |
| 21 | + watch (watcher) { |
| 22 | + this.watchers.push(watcher) |
| 23 | + } |
| 24 | + |
| 25 | + add (doms) { |
| 26 | + for (let dom of doms) { |
| 27 | + this.doms.push(dom) |
| 28 | + } |
| 29 | + } |
| 30 | + |
| 31 | + remove (doms) { |
| 32 | + let tmps = doms.slice() |
| 33 | + for (let i = this.doms.length - 1; i > -1; i--) { |
| 34 | + for (let j = tmps.length - 1; j > -1; j--) { |
| 35 | + if (this.doms[i].node === tmps[j].node) { |
| 36 | + this.doms.splice(i, 1) |
| 37 | + tmps.splice(j, 1) |
| 38 | + break |
| 39 | + } |
| 40 | + } |
| 41 | + } |
| 42 | + } |
| 43 | + |
| 44 | + update ({add: domList}) { |
| 45 | + let bindings = [] |
| 46 | + |
| 47 | + for (let dom of domList) { |
| 48 | + uniqueMerge(bindings, queryBindings(dom)) |
| 49 | + } |
| 50 | + |
| 51 | + let changed = diffBindingDOMs(this.doms, bindings) |
| 52 | + |
| 53 | + this.remove(changed.removed) |
| 54 | + this.add(changed.add) |
| 55 | + |
| 56 | + for (let watcher of this.watchers) { |
| 57 | + watcher(changed, this.doms) |
| 58 | + } |
| 59 | + } |
| 60 | +} |
| 61 | + |
| 62 | +function uniqueMerge (oldList, newList) { |
| 63 | + for (let i = 0; i < newList.length; i++) { |
| 64 | + let len = oldList.length |
| 65 | + let j = 0 |
| 66 | + for (j = 0; j < len; j++) { |
| 67 | + if (oldList[j].node === newList[i].node) { |
| 68 | + break |
| 69 | + } |
| 70 | + } |
| 71 | + if (j === len) { |
| 72 | + oldList.push(newList[i]) |
| 73 | + } |
| 74 | + } |
| 75 | + return oldList |
| 76 | +} |
| 77 | + |
| 78 | +function createBindingNodeWrapper (node, attrs) { |
| 79 | + let wrapper = { node, attrs } |
| 80 | + if (attrs) { |
| 81 | + wrapper.keys = Object.keys(attrs) |
| 82 | + } |
| 83 | + return wrapper |
| 84 | +} |
| 85 | + |
| 86 | +function queryBindings (root) { |
| 87 | + let results = [] |
| 88 | + traverse(root, node => { |
| 89 | + /* istanbul ignore if */ |
| 90 | + if (!isElementNode(node)) { |
| 91 | + return |
| 92 | + } |
| 93 | + let attrs = queryBindingAttrs(node) |
| 94 | + attrs && results.push(createBindingNodeWrapper(node, attrs)) |
| 95 | + if (node.children) { |
| 96 | + return Array.from(node.children) |
| 97 | + } |
| 98 | + }) |
| 99 | + return results |
| 100 | +} |
| 101 | + |
| 102 | +function queryBindingAttrs (node) { |
| 103 | + let attrs |
| 104 | + for (let i = 0; i < node.attributes.length; i++) { |
| 105 | + let attr = node.attributes[i] |
| 106 | + if (!isBindingAttr(attr.name)) { |
| 107 | + continue |
| 108 | + } |
| 109 | + attrs = attrs || {} |
| 110 | + attrs[attr.name] = {expr: attr.value} |
| 111 | + } |
| 112 | + return attrs |
| 113 | +} |
| 114 | + |
| 115 | +function diffBindingDOMs (storeList, newList) { |
| 116 | + let output = { |
| 117 | + removed: [], |
| 118 | + add: newList.slice() |
| 119 | + } |
| 120 | + |
| 121 | + for (let i = storeList.length - 1; i > -1; i--) { |
| 122 | + let stored = storeList[i] |
| 123 | + if (!document.contains(stored.node)) { |
| 124 | + output.removed.push(stored) |
| 125 | + continue |
| 126 | + } |
| 127 | + |
| 128 | + for (let j = output.add.length - 1; j > -1; j--) { |
| 129 | + if (stored.node === newList[j].node) { |
| 130 | + output.add.splice(j, 1) |
| 131 | + break |
| 132 | + } |
| 133 | + } |
| 134 | + } |
| 135 | + |
| 136 | + return output |
| 137 | +} |
| 138 | + |
| 139 | +export const instance = new DOMWatcher() |
| 140 | + |
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