/
helper.ts
255 lines (194 loc) · 6.45 KB
/
helper.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
/**
@module @ember/component
*/
import { Factory, Owner, setOwner } from '@ember/-internals/owner';
import { FrameworkObject } from '@ember/-internals/runtime';
import { getDebugName, symbol } from '@ember/-internals/utils';
import { join } from '@ember/runloop';
import { Arguments, Dict, HelperManager } from '@glimmer/interfaces';
import { getInternalHelperManager, helperCapabilities, setHelperManager } from '@glimmer/manager';
import { consumeTag, createTag, dirtyTag } from '@glimmer/validator';
export const RECOMPUTE_TAG = symbol('RECOMPUTE_TAG');
export type HelperFunction<T = unknown> = (positional: unknown[], named: Dict<unknown>) => T;
export type SimpleHelperFactory = Factory<SimpleHelper, HelperFactory<SimpleHelper>>;
export type ClassHelperFactory = Factory<HelperInstance, HelperFactory<HelperInstance>>;
export interface HelperFactory<T> {
isHelperFactory: true;
create(): T;
}
export interface HelperInstance<T = unknown> {
compute(positional: unknown[], named: Dict<unknown>): T;
destroy(): void;
}
export interface SimpleHelper<T = unknown> {
compute: HelperFunction<T>;
}
/**
Ember Helpers are functions that can compute values, and are used in templates.
For example, this code calls a helper named `format-currency`:
```app/templates/application.hbs
<Cost @cents={{230}} />
```
```app/components/cost.hbs
<div>{{format-currency @cents currency="$"}}</div>
```
Additionally a helper can be called as a nested helper.
In this example, we show the formatted currency value if the `showMoney`
named argument is truthy.
```handlebars
{{if @showMoney (format-currency @cents currency="$")}}
```
Helpers defined using a class must provide a `compute` function. For example:
```app/helpers/format-currency.js
import Helper from '@ember/component/helper';
export default class extends Helper {
compute([cents], { currency }) {
return `${currency}${cents * 0.01}`;
}
}
```
Each time the input to a helper changes, the `compute` function will be
called again.
As instances, these helpers also have access to the container and will accept
injected dependencies.
Additionally, class helpers can call `recompute` to force a new computation.
@class Helper
@extends CoreObject
@public
@since 1.13.0
*/
let Helper = FrameworkObject.extend({
init() {
this._super(...arguments);
this[RECOMPUTE_TAG] = createTag();
},
/**
On a class-based helper, it may be useful to force a recomputation of that
helpers value. This is akin to `rerender` on a component.
For example, this component will rerender when the `currentUser` on a
session service changes:
```app/helpers/current-user-email.js
import Helper from '@ember/component/helper'
import { service } from '@ember/service'
import { observer } from '@ember/object'
export default Helper.extend({
session: service(),
onNewUser: observer('session.currentUser', function() {
this.recompute();
}),
compute() {
return this.get('session.currentUser.email');
}
});
```
@method recompute
@public
@since 1.13.0
*/
recompute() {
join(() => dirtyTag(this[RECOMPUTE_TAG]));
},
/**
Override this function when writing a class-based helper.
@method compute
@param {Array} params The positional arguments to the helper
@param {Object} hash The named arguments to the helper
@public
@since 1.13.0
*/
});
const IS_CLASSIC_HELPER = symbol('IS_CLASSIC_HELPER');
Helper.isHelperFactory = true;
Helper[IS_CLASSIC_HELPER] = true;
export function isClassicHelper(obj: object): boolean {
return obj[IS_CLASSIC_HELPER] === true;
}
interface ClassicHelperStateBucket {
instance: HelperInstance;
args: Arguments;
}
class ClassicHelperManager implements HelperManager<ClassicHelperStateBucket> {
capabilities = helperCapabilities('3.23', {
hasValue: true,
hasDestroyable: true,
});
private ownerInjection: object;
constructor(owner: Owner | undefined) {
let ownerInjection = {};
setOwner(ownerInjection, owner!);
this.ownerInjection = ownerInjection;
}
createHelper(definition: typeof Helper, args: Arguments) {
let instance =
definition.class === undefined ? definition.create(this.ownerInjection) : definition.create();
return {
instance,
args,
};
}
getDestroyable({ instance }: ClassicHelperStateBucket) {
return instance;
}
getValue({ instance, args }: ClassicHelperStateBucket) {
let { positional, named } = args;
let ret = instance.compute(positional as unknown[], named);
consumeTag(instance[RECOMPUTE_TAG]);
return ret;
}
getDebugName(definition: ClassHelperFactory) {
return getDebugName!(definition.class!['prototype']);
}
}
setHelperManager((owner: Owner | undefined): ClassicHelperManager => {
return new ClassicHelperManager(owner);
}, Helper);
export const CLASSIC_HELPER_MANAGER = getInternalHelperManager(Helper);
///////////
class Wrapper implements HelperFactory<SimpleHelper> {
isHelperFactory: true = true;
constructor(public compute: HelperFunction) {}
create() {
// needs new instance or will leak containers
return {
compute: this.compute,
};
}
}
class SimpleClassicHelperManager implements HelperManager<() => unknown> {
capabilities = helperCapabilities('3.23', {
hasValue: true,
});
createHelper(definition: Wrapper, args: Arguments) {
let { compute } = definition;
return () => compute.call(null, args.positional as unknown[], args.named);
}
getValue(fn: () => unknown) {
return fn();
}
getDebugName(definition: Wrapper) {
return getDebugName!(definition.compute);
}
}
export const SIMPLE_CLASSIC_HELPER_MANAGER = new SimpleClassicHelperManager();
setHelperManager(() => SIMPLE_CLASSIC_HELPER_MANAGER, Wrapper.prototype);
/**
In many cases it is not necessary to use the full `Helper` class.
The `helper` method create pure-function helpers without instances.
For example:
```app/helpers/format-currency.js
import { helper } from '@ember/component/helper';
export default helper(function([cents], {currency}) {
return `${currency}${cents * 0.01}`;
});
```
@static
@param {Function} helper The helper function
@method helper
@for @ember/component/helper
@public
@since 1.13.0
*/
export function helper(helperFn: HelperFunction): HelperFactory<SimpleHelper> {
return new Wrapper(helperFn);
}
export default Helper as HelperFactory<HelperInstance>;