git ssb

1
var Value = require('./value')
2
var LazyWatcher = require('./lib/lazy-watcher')
3
var isSame = require('./lib/is-same')
4
var isObservable = require('./is-observable')
5
var resolve = require('./resolve')
6
var addCollectionMethods = require('./lib/add-collection-methods')
7
var forEach = require('./for-each')
8
9
module.exports = Array
10
11
function Array (defaultValues, opts) {
12
  var object = []
13
  var sources = []
14
  var releases = []
15
  var fixedIndexing = opts && opts.fixedIndexing || false
16
17
  var comparer = opts && opts.comparer || null
18
19
  var binder = LazyWatcher(update, listen, unlisten)
20
  binder.value = object
21
22
  if (opts && opts.nextTick) {
23
    binder.nextTick = true
24
  }
25
26
  if (defaultValues && defaultValues.length) {
27
    forEach(defaultValues, add)
28
  }
29
30
  var observable = function MutantArray (listener) {
31
    if (!listener) {
32
      return binder.getValue()
33
    }
34
    return binder.addListener(listener)
35
  }
36
37
  // getLength, get, indexOf, etc
38
  addCollectionMethods(observable, sources)
39
40
  observable.push = function (item) {
41
    var result = null
42
    if (arguments.length === 1) {
43
      result = add(item)
44
    } else {
45
      result = []
46
      for (var i = 0; i < arguments.length; i++) {
47
        result.push(add(arguments[i]))
48
      }
49
    }
50
    binder.broadcast()
51
    return result
52
  }
53
54
  observable.put = function (index, valueOrObs) {
55
    valueOrObs = getObsValue(valueOrObs)
56
    sources[index] = valueOrObs
57
    object[index] = resolve(valueOrObs)
58
    if (binder.live) {
59
      tryInvoke(releases[index])
60
      releases[index] = bind(valueOrObs)
61
    }
62
    binder.broadcast()
63
    return valueOrObs
64
  }
65
66
  observable.insert = function (valueOrObs, at) {
67
    valueOrObs = getObsValue(valueOrObs)
68
    sources.splice(at, 0, valueOrObs)
69
    if (binder.live) releases.splice(at, 0, bind(valueOrObs))
70
    object.splice(at, 0, resolve(valueOrObs))
71
    binder.broadcast()
72
    return valueOrObs
73
  }
74
75
  observable.pop = function () {
76
    var result = sources.pop()
77
    if (binder.live) tryInvoke(releases.pop())
78
    object.pop()
79
    binder.broadcast()
80
    return result
81
  }
82
83
  observable.shift = function () {
84
    var result = sources.shift()
85
    if (binder.live) tryInvoke(releases.shift())
86
    object.shift()
87
    binder.broadcast()
88
    return result
89
  }
90
91
  observable.clear = function () {
92
    releases.forEach(tryInvoke)
93
    sources.length = 0
94
    releases.length = 0
95
    object.length = 0
96
    binder.broadcast()
97
  }
98
99
  observable.delete = function (valueOrObs) {
100
    observable.deleteAt(sources.indexOf(valueOrObs))
101
  }
102
103
  observable.deleteAt = function (index) {
104
    if (index >= 0 && index < sources.length) {
105
      sources.splice(index, 1)
106
      if (binder.live) releases.splice(index, 1).forEach(tryInvoke)
107
      object.splice(index, 1)
108
      binder.broadcast()
109
    }
110
  }
111
112
  observable.transaction = function (cb) {
113
    binder.transaction(observable, cb)
114
  }
115
116
  observable.set = function (values) {
117
    var changed = false
118
    if (fixedIndexing) {
119
      var length = values && values.length || 0
120
      for (var i = 0; i < length; i++) {
121
        if (isObservable(values[i])) {
122
          if (values[i] !== sources[i]) {
123
            tryInvoke(releases[index])
124
            sources[i] = values[i]
125
            changed = true
126
            if (binder.live) {
127
              releases[i] = bind(sources[i])
128
            }
129
          }
130
        } else if (sources[i] && sources[i]._type === 'MutantArrayValue') {
131
          if (!isSame(sources[i](), values[i], comparer)) {
132
            sources[i].set(values[i])
133
            changed = true
134
          }
135
        } else {
136
          tryInvoke(releases[index])
137
          sources[i] = getObsValue(values[i])
138
          changed = true
139
          if (binder.live) {
140
            releases[i] = bind(sources[i])
141
          }
142
        }
143
      }
144
      for (var index = length; index < sources.length; index++) {
145
        tryInvoke(releases[index])
146
        changed = true
147
      }
148
149
      if (changed) {
150
        releases.length = length
151
        sources.length = length
152
        object.length = length
153
        binder.broadcast()
154
      }
155
    } else {
156
      unlisten()
157
      sources.length = 0
158
      releases.length = 0
159
      object.length = 0
160
      forEach(values, add)
161
      if (binder.live) {
162
        listen()
163
        binder.broadcast()
164
      }
165
    }
166
  }
167
168
  return observable
169
170
  // scoped
171
172
  function getObsValue (valueOrObs) {
173
    if (fixedIndexing && !isObservable(valueOrObs)) {
174
      valueOrObs = Value(valueOrObs)
175
      valueOrObs._type = 'MutantArrayValue'
176
    }
177
    return valueOrObs
178
  }
179
180
  function add (valueOrObs) {
181
    valueOrObs = getObsValue(valueOrObs)
182
    sources.push(valueOrObs)
183
    object.push(resolve(valueOrObs))
184
    if (binder.live) {
185
      releases.push(bind(valueOrObs))
186
    }
187
    return valueOrObs
188
  }
189
190
  function bind (valueOrObs) {
191
    return typeof valueOrObs === 'function' ? valueOrObs(binder.onUpdate) : null
192
  }
193
194
  function listen () {
195
    sources.forEach(function (obs, i) {
196
      releases[i] = bind(obs)
197
    })
198
199
    if (opts && opts.onListen) {
200
      var release = opts.onListen()
201
      if (typeof release === 'function') {
202
        releases.push(release)
203
      }
204
    }
205
  }
206
207
  function unlisten () {
208
    releases.forEach(tryInvoke)
209
    releases.length = 0
210
211
    if (opts && opts.onUnlisten) {
212
      opts.onUnlisten()
213
    }
214
  }
215
216
  function update () {
217
    var changed = false
218
    sources.forEach(function (source, i) {
219
      var newValue = resolve(source)
220
      if (!isSame(newValue, object[i], comparer)) {
221
        object[i] = newValue
222
        changed = true
223
      }
224
    })
225
    return changed
226
  }
227
}
228
229
function tryInvoke (func) {
230
  if (typeof func === 'function') {
231
    func()
232
  }
233
}
234