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