-
-
Notifications
You must be signed in to change notification settings - Fork 4.2k
/
events.js
286 lines (242 loc) · 7.57 KB
/
events.js
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
/**
@module @ember/object
*/
import { applyStr } from 'ember-utils';
import { deprecate, assert } from 'ember-debug';
import { meta as metaFor, peekMeta } from './meta';
import { ONCE, SUSPENDED } from './meta_listeners';
/*
The event system uses a series of nested hashes to store listeners on an
object. When a listener is registered, or when an event arrives, these
hashes are consulted to determine which target and action pair to invoke.
The hashes are stored in the object's meta hash, and look like this:
// Object's meta hash
{
listeners: { // variable name: `listenerSet`
"foo:changed": [ // variable name: `actions`
target, method, flags
]
}
}
*/
/**
Add an event listener
@method addListener
@static
@for @ember/object/events
@param obj
@param {String} eventName
@param {Object|Function} target A target object or a function
@param {Function|String} method A function or the name of a function to be called on `target`
@param {Boolean} once A flag whether a function should only be called once
@public
*/
export function addListener(obj, eventName, target, method, once) {
assert('You must pass at least an object and event name to addListener', !!obj && !!eventName);
deprecate(
`didInitAttrs called in ${obj && obj.toString && obj.toString()}.`,
eventName !== 'didInitAttrs',
{
id: 'ember-views.did-init-attrs',
until: '3.0.0',
url: 'https://emberjs.com/deprecations/v2.x#toc_ember-component-didinitattrs'
}
);
if (!method && 'function' === typeof target) {
method = target;
target = null;
}
let flags = 0;
if (once) {
flags |= ONCE;
}
metaFor(obj).addToListeners(eventName, target, method, flags);
if ('function' === typeof obj.didAddListener) {
obj.didAddListener(eventName, target, method);
}
}
/**
Remove an event listener
Arguments should match those passed to `addListener`.
@method removeListener
@static
@for @ember/object/events
@param obj
@param {String} eventName
@param {Object|Function} target A target object or a function
@param {Function|String} method A function or the name of a function to be called on `target`
@public
*/
export function removeListener(obj, eventName, target, method) {
assert('You must pass at least an object and event name to removeListener', !!obj && !!eventName);
if (!method && 'function' === typeof target) {
method = target;
target = null;
}
let func = ('function' === typeof obj.didRemoveListener) ?
obj.didRemoveListener.bind(obj) : ()=> {};
metaFor(obj).removeFromListeners(eventName, target, method, func);
}
/**
Suspend listener during callback.
This should only be used by the target of the event listener
when it is taking an action that would cause the event, e.g.
an object might suspend its property change listener while it is
setting that property.
@method suspendListener
@static
@for @ember/object/events
@private
@param obj
@param {String} eventName
@param {Object|Function} target A target object or a function
@param {Function|String} method A function or the name of a function to be called on `target`
@param {Function} callback
*/
export function suspendListener(obj, eventName, target, method, callback) {
return suspendListeners(obj, [eventName], target, method, callback);
}
/**
Suspends multiple listeners during a callback.
@method suspendListeners
@static
@for @ember/object/events
@private
@param obj
@param {Array} eventNames Array of event names
@param {Object|Function} target A target object or a function
@param {Function|String} method A function or the name of a function to be called on `target`
@param {Function} callback
*/
export function suspendListeners(obj, eventNames, target, method, callback) {
if (!method && 'function' === typeof target) {
method = target;
target = null;
}
return metaFor(obj).suspendListeners(eventNames, target, method, callback);
}
/**
Return a list of currently watched events
@private
@method watchedEvents
@static
@for @ember/object/events
@param obj
*/
export function watchedEvents(obj) {
let meta = peekMeta(obj);
return meta !== undefined ? meta.watchedEvents() : [];
}
/**
Send an event. The execution of suspended listeners
is skipped, and once listeners are removed. A listener without
a target is executed on the passed object. If an array of actions
is not passed, the actions stored on the passed object are invoked.
@method sendEvent
@static
@for @ember/object/events
@param obj
@param {String} eventName
@param {Array} params Optional parameters for each listener.
@param {Array} actions Optional array of actions (listeners).
@param {Meta} meta Optional meta to lookup listeners
@return true
@public
*/
export function sendEvent(obj, eventName, params, actions, _meta) {
if (actions === undefined) {
let meta = _meta === undefined ? peekMeta(obj) : _meta;
actions = typeof meta === 'object' &&
meta !== null &&
meta.matchingListeners(eventName);
}
if (actions === undefined || actions.length === 0) { return false; }
for (let i = actions.length - 3; i >= 0; i -= 3) { // looping in reverse for once listeners
let target = actions[i];
let method = actions[i + 1];
let flags = actions[i + 2];
if (!method) { continue; }
if (flags & SUSPENDED) { continue; }
if (flags & ONCE) { removeListener(obj, eventName, target, method); }
if (!target) { target = obj; }
if ('string' === typeof method) {
if (params) {
applyStr(target, method, params);
} else {
target[method]();
}
} else {
if (params) {
method.apply(target, params);
} else {
method.call(target);
}
}
}
return true;
}
/**
@private
@method hasListeners
@static
@for @ember/object/events
@param obj
@param {String} eventName
*/
export function hasListeners(obj, eventName) {
let meta = peekMeta(obj);
if (meta === undefined) { return false; }
let matched = meta.matchingListeners(eventName);
return matched !== undefined && matched.length > 0;
}
/**
@private
@method listenersFor
@static
@for @ember/object/events
@param obj
@param {String} eventName
*/
export function listenersFor(obj, eventName) {
let ret = [];
let meta = peekMeta(obj);
let actions = meta !== undefined ? meta.matchingListeners(eventName) : undefined;
if (actions === undefined) { return ret; }
for (let i = 0; i < actions.length; i += 3) {
let target = actions[i];
let method = actions[i + 1];
ret.push([target, method]);
}
return ret;
}
/**
Define a property as a function that should be executed when
a specified event or events are triggered.
``` javascript
import EmberObject from '@ember/object';
import { on } from '@ember/object/evented';
import { sendEvent } from '@ember/object/events';
let Job = EmberObject.extend({
logCompleted: on('completed', function() {
console.log('Job completed!');
})
});
let job = Job.create();
sendEvent(job, 'completed'); // Logs 'Job completed!'
```
@method on
@static
@for @ember/object/evented
@param {String} eventNames*
@param {Function} func
@return func
@public
*/
export function on(...args) {
let func = args.pop();
let events = args;
assert('on expects function as last argument', typeof func === 'function');
assert('on called without valid event names', events.length > 0 && events.every((p)=> typeof p === 'string' && p.length));
func.__ember_listens__ = events;
return func;
}