Files: 5be33c01238870a66c608fed4ece3fbc43069a51 / html-element.js
6156 bytesRaw
1 | var applyProperties = require('./lib/apply-properties') |
2 | var isObservable = require('./is-observable') |
3 | var parseTag = require('./lib/parse-tag') |
4 | var walk = require('./lib/walk') |
5 | var watch = require('./watch') |
6 | var caches = new global.WeakMap() |
7 | var watcher = null |
8 | var invalidateNextTick = require('./lib/invalidate-next-tick') |
9 | |
10 | module.exports = function (tag, attributes, children) { |
11 | return Element(global.document, null, tag, attributes, children) |
12 | } |
13 | |
14 | module.exports.forDocument = function (document, namespace) { |
15 | return Element.bind(this, document, namespace) |
16 | } |
17 | |
18 | function Element (document, namespace, tagName, properties, children) { |
19 | if (!children && (Array.isArray(properties) || isText(properties))) { |
20 | children = properties |
21 | properties = null |
22 | } |
23 | |
24 | checkWatcher(document) |
25 | properties = properties || {} |
26 | |
27 | var tag = parseTag(tagName, properties, namespace) |
28 | var node = namespace |
29 | ? document.createElementNS(namespace, tag.tagName) |
30 | : document.createElement(tag.tagName) |
31 | |
32 | if (tag.id) { |
33 | node.id = tag.id |
34 | } |
35 | |
36 | if (tag.classes && tag.classes.length) { |
37 | node.className = tag.classes.join(' ') |
38 | } |
39 | |
40 | var data = { |
41 | targets: new Map(), |
42 | bindings: [] |
43 | } |
44 | |
45 | caches.set(node, data) |
46 | applyProperties(node, properties, data) |
47 | if (children != null) { |
48 | appendChild(document, node, data, children) |
49 | } |
50 | |
51 | return node |
52 | } |
53 | |
54 | function appendChild (document, target, data, node) { |
55 | if (Array.isArray(node)) { |
56 | node.forEach(function (child) { |
57 | appendChild(document, target, data, child) |
58 | }) |
59 | } else if (isObservable(node)) { |
60 | var nodes = getNodes(document, resolve(node)) |
61 | nodes.forEach(append, target) |
62 | data.targets.set(node, nodes) |
63 | data.bindings.push(new Binding(document, node, data)) |
64 | } else { |
65 | node = getNode(document, node) |
66 | target.appendChild(node) |
67 | walk(node, rebind) |
68 | } |
69 | } |
70 | |
71 | function append (child) { |
72 | this.appendChild(child) |
73 | walk(child, rebind) |
74 | } |
75 | |
76 | function checkWatcher (document) { |
77 | if (!watcher && global.MutationObserver) { |
78 | watcher = new global.MutationObserver(onMutate) |
79 | watcher.observe(document, {subtree: true, childList: true}) |
80 | } |
81 | } |
82 | |
83 | function onMutate (changes) { |
84 | changes.forEach(handleChange) |
85 | } |
86 | |
87 | function handleChange (change) { |
88 | for (var i = 0; i < change.addedNodes.length; i++) { |
89 | // if parent is a mutant element, then safe to assume it has already been bound |
90 | var node = change.addedNodes[i] |
91 | if (!caches.has(node.parentNode)) { |
92 | walk(node, rebind) |
93 | } |
94 | } |
95 | for (var i = 0; i < change.removedNodes.length; i++) { |
96 | // if has already been unbound, safe to assume children have also |
97 | var node = change.removedNodes[i] |
98 | var data = caches.get(node) |
99 | if (data && data.bound) { |
100 | walk(node, unbind) |
101 | } |
102 | } |
103 | } |
104 | |
105 | function indexOf (target, item) { |
106 | return Array.prototype.indexOf.call(target, item) |
107 | } |
108 | |
109 | function replace (oldNodes, newNodes) { |
110 | var parent = oldNodes[oldNodes.length - 1].parentNode |
111 | var nodes = parent.childNodes |
112 | var startIndex = indexOf(nodes, oldNodes[0]) |
113 | |
114 | // avoid reinserting nodes that are already in correct position! |
115 | for (var i = 0; i < newNodes.length; i++) { |
116 | if (nodes[i + startIndex] === newNodes[i]) { |
117 | continue |
118 | } else if (nodes[i + startIndex + 1] === newNodes[i]) { |
119 | parent.removeChild(nodes[i + startIndex]) |
120 | continue |
121 | } else if (nodes[i + startIndex] === newNodes[i + 1] && newNodes[i + 1]) { |
122 | parent.insertBefore(newNodes[i], nodes[i + startIndex]) |
123 | } else if (nodes[i + startIndex]) { |
124 | parent.insertBefore(newNodes[i], nodes[i + startIndex]) |
125 | } else { |
126 | parent.appendChild(newNodes[i]) |
127 | } |
128 | walk(newNodes[i], rebind) |
129 | } |
130 | |
131 | oldNodes.filter(function (node) { |
132 | return !~newNodes.indexOf(node) |
133 | }).forEach(function (node) { |
134 | if (node.parentNode) { |
135 | parent.removeChild(node) |
136 | } |
137 | walk(node, unbind) |
138 | }) |
139 | } |
140 | |
141 | function isText (value) { |
142 | return typeof value === 'string' || typeof value === 'number' || typeof value === 'boolean' |
143 | } |
144 | |
145 | function getNode (document, nodeOrText) { |
146 | if (nodeOrText == null) { |
147 | return document.createTextNode('') |
148 | } else if (isText(nodeOrText)) { |
149 | return document.createTextNode(nodeOrText.toString()) |
150 | } else { |
151 | return nodeOrText |
152 | } |
153 | } |
154 | |
155 | function getNodes (document, nodeOrNodes) { |
156 | if (Array.isArray(nodeOrNodes)) { |
157 | if (nodeOrNodes.length) { |
158 | var result = [] |
159 | for (var i = 0; i < nodeOrNodes.length; i++) { |
160 | var item = nodeOrNodes[i] |
161 | if (Array.isArray(item)) { |
162 | getNodes(document, item).forEach(push, result) |
163 | } else { |
164 | result.push(getNode(document, item)) |
165 | } |
166 | } |
167 | return result.map(getNode.bind(this, document)) |
168 | } else { |
169 | return [getNode(document, null)] |
170 | } |
171 | } else { |
172 | return [getNode(document, nodeOrNodes)] |
173 | } |
174 | } |
175 | |
176 | function rebind (node) { |
177 | if (node.nodeType === 1) { |
178 | var data = caches.get(node) |
179 | if (data) { |
180 | data.bindings.forEach(invokeBind) |
181 | } |
182 | } |
183 | } |
184 | |
185 | function unbind (node) { |
186 | if (node.nodeType === 1) { |
187 | var data = caches.get(node) |
188 | if (data) { |
189 | data.bindings.forEach(invokeUnbind) |
190 | } |
191 | } |
192 | } |
193 | |
194 | function invokeBind (binding) { |
195 | binding.bind() |
196 | } |
197 | |
198 | function invokeUnbind (binding) { |
199 | binding.unbind() |
200 | } |
201 | |
202 | function push (item) { |
203 | this.push(item) |
204 | } |
205 | |
206 | function resolve (source) { |
207 | return typeof source === 'function' ? source() : source |
208 | } |
209 | |
210 | function Binding (document, obs, data) { |
211 | this.document = document |
212 | this.obs = obs |
213 | this.data = data |
214 | this.bound = false |
215 | this.invalid = false |
216 | this.update = function (value) { |
217 | var oldNodes = data.targets.get(obs) |
218 | var newNodes = getNodes(document, value) |
219 | if (oldNodes) { |
220 | replace(oldNodes, newNodes) |
221 | data.targets.set(obs, newNodes) |
222 | } |
223 | } |
224 | invalidateNextTick(this) |
225 | } |
226 | |
227 | Binding.prototype = { |
228 | bind: function () { |
229 | if (!this.bound) { |
230 | this._release = this.invalid |
231 | ? watch(this.obs, this.update) |
232 | : this.obs(this.update) |
233 | this.invalid = false |
234 | this.bound = true |
235 | } |
236 | }, |
237 | unbind: function () { |
238 | if (this.bound && typeof this._release === 'function') { |
239 | this._release() |
240 | this._release = null |
241 | this.bound = false |
242 | invalidateNextTick(this) |
243 | } |
244 | } |
245 | } |
246 |
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