OLD | NEW |
(Empty) | |
| 1 |
| 2 (function(){ |
| 3 /** |
| 4 `iron-signals` provides basic publish-subscribe functionality. |
| 5 |
| 6 Note: avoid using `iron-signals` whenever you can use |
| 7 a controller (parent element) to mediate communication |
| 8 instead. |
| 9 |
| 10 To send a signal, fire a custom event of type `iron-signal`, with |
| 11 a detail object containing `name` and `data` fields. |
| 12 |
| 13 this.fire('iron-signal', {name: 'hello', data: null}); |
| 14 |
| 15 To receive a signal, listen for `iron-signal-<name>` event on a |
| 16 `iron-signals` element. |
| 17 |
| 18 <iron-signals on-iron-signal-hello="{{helloSignal}}"> |
| 19 |
| 20 You can fire a signal event from anywhere, and all |
| 21 `iron-signals` elements will receive the event, regardless |
| 22 of where they are in DOM. |
| 23 |
| 24 @demo demo/index.html |
| 25 */ |
| 26 Polymer({ |
| 27 is: 'iron-signals', |
| 28 |
| 29 attached: function() { |
| 30 signals.push(this); |
| 31 }, |
| 32 detached: function() { |
| 33 var i = signals.indexOf(this); |
| 34 if (i >= 0) { |
| 35 signals.splice(i, 1); |
| 36 } |
| 37 } |
| 38 }); |
| 39 |
| 40 // private shared database |
| 41 var signals = []; |
| 42 |
| 43 // signal dispatcher |
| 44 function notify(name, data) { |
| 45 // convert generic-signal event to named-signal event |
| 46 var signal = new CustomEvent('iron-signal-' + name, { |
| 47 // if signals bubble, it's easy to get confusing duplicates |
| 48 // (1) listen on a container on behalf of local child |
| 49 // (2) some deep child ignores the event and it bubbles |
| 50 // up to said container |
| 51 // (3) local child event bubbles up to container |
| 52 // also, for performance, we avoid signals flying up the |
| 53 // tree from all over the place |
| 54 bubbles: false, |
| 55 detail: data |
| 56 }); |
| 57 // dispatch named-signal to all 'signals' instances, |
| 58 // only interested listeners will react |
| 59 signals.forEach(function(s) { |
| 60 s.dispatchEvent(signal); |
| 61 }); |
| 62 } |
| 63 |
| 64 // signal listener at document |
| 65 document.addEventListener('iron-signal', function(e) { |
| 66 notify(e.detail.name, e.detail.data); |
| 67 }); |
| 68 |
| 69 })(); |
OLD | NEW |