git ssb

1
var resolve = require('./resolve')
2
var isObservable = require('./is-observable')
3
4
module.exports = watchAll
5
6
function watchAll (observables, listener, opts) {
7
  if (!Array.isArray(observables)) {
8
    observables = [ observables ]
9
  }
10
11
  var broadcasting = false
12
  var releases = observables.map(bind, broadcast)
13
14
  broadcast()
15
16
  return function () {
17
    releases.forEach(tryInvoke)
18
    releases.length = 0
19
  }
20
21
  function broadcast () {
22
    if (opts && opts.nextTick) {
23
      if (!broadcasting) {
24
        broadcasting = true
25
        setImmediate(broadcastNow)
26
      }
27
    } else {
28
      broadcastNow()
29
    }
30
  }
31
32
  function broadcastNow () {
33
    broadcasting = false
34
    listener.apply(this, observables.map(resolve))
35
  }
36
}
37
38
function bind (value) {
39
  if (isObservable(value)) {
40
    return value(this)
41
  }
42
}
43
44
function tryInvoke (value) {
45
  if (typeof value === 'function') {
46
    return value()
47
  }
48
}
49