-
Notifications
You must be signed in to change notification settings - Fork 24.8k
/
action_resolver.ts
281 lines (259 loc) Β· 10.8 KB
/
action_resolver.ts
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
/**
* @license
* Copyright Google LLC All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import {Attribute} from './attribute';
import {Char} from './char';
import {EventType} from './event_type';
import {OWNER} from './property';
import * as a11yClick from './a11y_click';
import * as cache from './cache';
import * as eventInfoLib from './event_info';
import * as eventLib from './event';
/**
* Since maps from event to action are immutable we can use a single map
* to represent the empty map.
*/
const EMPTY_ACTION_MAP: {[key: string]: string} = {};
/**
* This regular expression matches a semicolon.
*/
const REGEXP_SEMICOLON = /\s*;\s*/;
/** If no event type is defined, defaults to `click`. */
const DEFAULT_EVENT_TYPE: string = EventType.CLICK;
/** Resolves actions for Events. */
export class ActionResolver {
private a11yClickSupport: boolean = false;
private readonly customEventSupport: boolean;
private readonly syntheticMouseEventSupport: boolean;
private updateEventInfoForA11yClick?: (eventInfo: eventInfoLib.EventInfo) => void = undefined;
private preventDefaultForA11yClick?: (eventInfo: eventInfoLib.EventInfo) => void = undefined;
private populateClickOnlyAction?: (
actionElement: Element,
eventInfo: eventInfoLib.EventInfo,
actionMap: {[key: string]: string},
) => void = undefined;
constructor({
customEventSupport = false,
syntheticMouseEventSupport = false,
}: {
customEventSupport?: boolean;
syntheticMouseEventSupport?: boolean;
} = {}) {
this.customEventSupport = customEventSupport;
this.syntheticMouseEventSupport = syntheticMouseEventSupport;
}
resolve(eventInfo: eventInfoLib.EventInfo) {
if (this.customEventSupport) {
if (eventInfoLib.getEventType(eventInfo) === EventType.CUSTOM) {
const detail = (eventInfoLib.getEvent(eventInfo) as CustomEvent).detail;
// For custom events, use a secondary dispatch based on the internal
// custom type of the event.
if (!detail || !detail['_type']) {
// This should never happen.
return;
}
eventInfoLib.setEventType(eventInfo, detail['_type']);
}
}
this.populateAction(eventInfo);
}
/**
* Searches for a jsaction that the DOM event maps to and creates an
* object containing event information used for dispatching by
* jsaction.Dispatcher. This method populates the `action` and `actionElement`
* fields of the EventInfo object passed in by finding the first
* jsaction attribute above the target Node of the event, and below
* the container Node, that specifies a jsaction for the event
* type. If no such jsaction is found, then action is undefined.
*
* @param eventInfo `EventInfo` to set `action` and `actionElement` if an
* action is found on any `Element` in the path of the `Event`.
*/
private populateAction(eventInfo: eventInfoLib.EventInfo) {
// We distinguish modified and plain clicks in order to support the
// default browser behavior of modified clicks on links; usually to
// open the URL of the link in new tab or new window on ctrl/cmd
// click. A DOM 'click' event is mapped to the jsaction 'click'
// event iff there is no modifier present on the event. If there is
// a modifier, it's mapped to 'clickmod' instead.
//
// It's allowed to omit the event in the jsaction attribute. In that
// case, 'click' is assumed. Thus the following two are equivalent:
//
// <a href="someurl" jsaction="gna.fu">
// <a href="someurl" jsaction="click:gna.fu">
//
// For unmodified clicks, EventContract invokes the jsaction
// 'gna.fu'. For modified clicks, EventContract won't find a
// suitable action and leave the event to be handled by the
// browser.
//
// In order to also invoke a jsaction handler for a modifier click,
// 'clickmod' needs to be used:
//
// <a href="someurl" jsaction="clickmod:gna.fu">
//
// EventContract invokes the jsaction 'gna.fu' for modified
// clicks. Unmodified clicks are left to the browser.
//
// In order to set up the event contract to handle both clickonly and
// clickmod, only addEvent(EventType.CLICK) is necessary.
//
// In order to set up the event contract to handle click,
// addEvent() is necessary for CLICK, KEYDOWN, and KEYPRESS event types. If
// a11y click support is enabled, addEvent() will set up the appropriate key
// event handler automatically.
if (
eventInfoLib.getEventType(eventInfo) === EventType.CLICK &&
eventLib.isModifiedClickEvent(eventInfoLib.getEvent(eventInfo))
) {
eventInfoLib.setEventType(eventInfo, EventType.CLICKMOD);
} else if (this.a11yClickSupport) {
this.updateEventInfoForA11yClick!(eventInfo);
}
// Walk to the parent node, unless the node has a different owner in
// which case we walk to the owner. Attempt to walk to host of a
// shadow root if needed.
let actionElement: Element | null = eventInfoLib.getTargetElement(eventInfo);
while (actionElement && actionElement !== eventInfoLib.getContainer(eventInfo)) {
if (actionElement.nodeType === Node.ELEMENT_NODE) {
this.populateActionOnElement(actionElement, eventInfo);
}
if (eventInfoLib.getAction(eventInfo)) {
// An event is handled by at most one jsaction. Thus we stop at the
// first matching jsaction specified in a jsaction attribute up the
// ancestor chain of the event target node.
break;
}
if (actionElement[OWNER]) {
actionElement = actionElement[OWNER] as Element;
continue;
}
if (actionElement.parentNode?.nodeName !== '#document-fragment') {
actionElement = actionElement.parentNode as Element | null;
} else {
actionElement = (actionElement.parentNode as ShadowRoot | null)?.host ?? null;
}
}
const action = eventInfoLib.getAction(eventInfo);
if (!action) {
// No action found.
return;
}
if (this.a11yClickSupport) {
this.preventDefaultForA11yClick!(eventInfo);
}
// We attempt to handle the mouseenter/mouseleave events here by
// detecting whether the mouseover/mouseout events correspond to
// entering/leaving an element.
if (this.syntheticMouseEventSupport) {
if (
eventInfoLib.getEventType(eventInfo) === EventType.MOUSEENTER ||
eventInfoLib.getEventType(eventInfo) === EventType.MOUSELEAVE ||
eventInfoLib.getEventType(eventInfo) === EventType.POINTERENTER ||
eventInfoLib.getEventType(eventInfo) === EventType.POINTERLEAVE
) {
// We attempt to handle the mouseenter/mouseleave events here by
// detecting whether the mouseover/mouseout events correspond to
// entering/leaving an element.
if (
eventLib.isMouseSpecialEvent(
eventInfoLib.getEvent(eventInfo),
eventInfoLib.getEventType(eventInfo),
eventInfoLib.getActionElement(action),
)
) {
// If both mouseover/mouseout and mouseenter/mouseleave events are
// enabled, two separate handlers for mouseover/mouseout are
// registered. Both handlers will see the same event instance
// so we create a copy to avoid interfering with the dispatching of
// the mouseover/mouseout event.
const copiedEvent = eventLib.createMouseSpecialEvent(
eventInfoLib.getEvent(eventInfo),
eventInfoLib.getActionElement(action),
);
eventInfoLib.setEvent(eventInfo, copiedEvent);
// Since the mouseenter/mouseleave events do not bubble, the target
// of the event is technically the `actionElement` (the node with the
// `jsaction` attribute)
eventInfoLib.setTargetElement(eventInfo, eventInfoLib.getActionElement(action));
} else {
eventInfoLib.unsetAction(eventInfo);
}
}
}
}
/**
* Accesses the jsaction map on a node and retrieves the name of the
* action the given event is mapped to, if any. It parses the
* attribute value and stores it in a property on the node for
* subsequent retrieval without re-parsing and re-accessing the
* attribute.
*
* @param actionElement The DOM node to retrieve the jsaction map from.
* @param eventInfo `EventInfo` to set `action` and `actionElement` if an
* action is found on the `actionElement`.
*/
private populateActionOnElement(actionElement: Element, eventInfo: eventInfoLib.EventInfo) {
const actionMap = this.parseActions(actionElement);
const actionName = actionMap[eventInfoLib.getEventType(eventInfo)];
if (actionName !== undefined) {
eventInfoLib.setAction(eventInfo, actionName, actionElement);
}
if (this.a11yClickSupport) {
this.populateClickOnlyAction!(actionElement, eventInfo, actionMap);
}
}
/**
* Parses and caches an element's jsaction element into a map.
*
* This is primarily for internal use.
*
* @param actionElement The DOM node to retrieve the jsaction map from.
* @return Map from event to qualified name of the jsaction bound to it.
*/
private parseActions(actionElement: Element): {[key: string]: string} {
let actionMap: {[key: string]: string} | undefined = cache.get(actionElement);
if (!actionMap) {
const jsactionAttribute = actionElement.getAttribute(Attribute.JSACTION);
if (!jsactionAttribute) {
actionMap = EMPTY_ACTION_MAP;
cache.set(actionElement, actionMap);
} else {
actionMap = cache.getParsed(jsactionAttribute);
if (!actionMap) {
actionMap = {};
const values = jsactionAttribute.split(REGEXP_SEMICOLON);
for (let idx = 0; idx < values.length; idx++) {
const value = values[idx];
if (!value) {
continue;
}
const colon = value.indexOf(Char.EVENT_ACTION_SEPARATOR);
const hasColon = colon !== -1;
const type = hasColon ? value.substr(0, colon).trim() : DEFAULT_EVENT_TYPE;
const action = hasColon ? value.substr(colon + 1).trim() : value;
actionMap[type] = action;
}
cache.setParsed(jsactionAttribute, actionMap);
}
cache.set(actionElement, actionMap);
}
}
return actionMap;
}
addA11yClickSupport(
updateEventInfoForA11yClick: typeof a11yClick.updateEventInfoForA11yClick,
preventDefaultForA11yClick: typeof a11yClick.preventDefaultForA11yClick,
populateClickOnlyAction: typeof a11yClick.populateClickOnlyAction,
) {
this.a11yClickSupport = true;
this.updateEventInfoForA11yClick = updateEventInfoForA11yClick;
this.preventDefaultForA11yClick = preventDefaultForA11yClick;
this.populateClickOnlyAction = populateClickOnlyAction;
}
}