Repository navigation
Expand file tree
/
Copy pathdirectives.ts
More file actions
1107 lines (1053 loc) · 34.3 KB
/
Copy pathdirectives.ts
File metadata and controls
1107 lines (1053 loc) · 34.3 KB
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
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
/**
* @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.dev/license
*/
import {ChangeDetectionStrategy} from '../change_detection/constants';
import {Provider} from '../di/interface/provider';
import {ForeignComponent} from '../interface/foreign_component';
import {Type} from '../interface/type';
import {compileComponent, compileDirective} from '../render3/jit/directive';
import {compilePipe} from '../render3/jit/pipe';
import {makeDecorator, makePropDecorator, TypeDecorator} from '../util/decorators';
import {SchemaMetadata} from './schema';
import {ViewEncapsulation} from './view';
/**
* Type of the Directive decorator / constructor function.
* @publicApi
*/
export interface DirectiveDecorator {
/**
* Decorator that marks a class as an Angular directive.
* You can define your own directives to attach custom behavior to elements in the DOM.
*
* The options provide configuration metadata that determines
* how the directive should be processed, instantiated and used at
* runtime.
*
* Directive classes, like component classes, can implement
* [life-cycle hooks](guide/components/lifecycle) to influence their configuration and behavior.
*
*
* @usageNotes
* To define a directive, mark the class with the decorator and provide metadata.
*
* ```ts
* import {Directive} from '@angular/core';
*
* @Directive({
* selector: 'my-directive',
* })
* export class MyDirective {
* ...
* }
* ```
*
* ### Declaring directives
*
* By default, directives are marked as standalone, which makes
* them available to other components in your application.
*
* ```ts
* @Directive({
* selector: 'my-directive',
* })
* ```
*
* Please make sure that directives marked as standalone are not already declared in an NgModule.
*
* ** Declaring a directive in an NgModule **
* If you want to declare a directive in an ngModule, add the `standalone: false` flag to the
* Directive decorator metadata and add the directive to the `declarations` and `exports`
* fields of your ngModule.
*
* ```ts
* @Directive({
* standalone: false,
* selector: 'my-directive',
* })
* class MyDirective {}
*
* @NgModule({
* declarations: [MyDirective, SomeComponent],
* exports: [MyDirective], // making it available outside of this module
* })
* class SomeNgModule {}
* ```
*
* When declaring a directive in an NgModule, please make sure that:
* - the directive is declared in exactly one NgModule.
* - the directive is not standalone.
* - you do not re-declare a directive imported from another module.
* - the directive is included into the `exports` field as well if you want this directive to be
* accessible for components outside of the NgModule.
*
*
* @Annotation
*/
(obj?: Directive): TypeDecorator;
/**
* See the `Directive` decorator.
*/
new (obj?: Directive): Directive;
}
/**
* Directive decorator and metadata.
*
* @see [Built-in directives](guide/directives)
* @see [Including inputs and outputs](guide/directives/directive-composition-api#including-inputs-and-outputs)
* @see [Assigning a reference to an Angular directive](guide/templates/variables#assigning-a-reference-to-an-angular-directive)
* @see [Referencing component children with queries](guide/components/queries)
* @see [Binding to the host element](guide/components/host-elements#binding-to-the-host-element)
* @see [Host directive semantics](guide/directives/directive-composition-api#host-directive-semantics)
* @Annotation
* @publicApi
*/
export interface Directive {
/**
* The CSS selector that identifies this directive in a template
* and triggers instantiation of the directive.
*
* Declare as one of the following:
*
* - `element-name`: Select by element name.
* - `.class`: Select by class name.
* - `[attribute]`: Select by attribute name.
* - `[attribute=value]`: Select by attribute name and value.
* - `:not(sub_selector)`: Select only if the element does not match the `sub_selector`.
* - `selector1, selector2`: Select if either `selector1` or `selector2` matches.
*
* Angular only allows directives to apply on CSS selectors that do not cross
* element boundaries.
*
* For the following template HTML, a directive with an `input[type=text]` selector,
* would be instantiated only on the `<input type="text">` element.
*
* ```html
* <form>
* <input type="text">
* <input type="radio">
* <form>
* ```
*
*/
selector?: string;
/**
* Enumerates the set of data-bound input properties for a directive
*
* Angular automatically updates input properties during change detection.
* The `inputs` property accepts either strings or object literals that configure the directive
* properties that should be exposed as inputs.
*
* When an object literal is passed in, the `name` property indicates which property on the
* class the input should write to, while the `alias` determines the name under
* which the input will be available in template bindings. The `required` property indicates that
* the input is required which will trigger a compile-time error if it isn't passed in when the
* directive is used.
*
* When a string is passed into the `inputs` array, it can have a format of `'name'` or
* `'name: alias'` where `name` is the property on the class that the directive should write
* to, while the `alias` determines the name under which the input will be available in
* template bindings. String-based input definitions are assumed to be optional.
*
* @usageNotes
*
* The following example creates a component with two data-bound properties.
*
* ```ts
* @Component({
* selector: 'bank-account',
* inputs: ['bankName', {name: 'id', alias: 'account-id'}],
* template: `
* Bank Name: {{bankName}}
* Account Id: {{id}}
* `
* })
* class BankAccount {
* bankName: string;
* id: string;
* }
* ```
*
*/
inputs?: (
| {
name: string;
alias?: string;
required?: boolean;
transform?: (value: any) => any;
}
| string
)[];
/**
* Enumerates the set of event-bound output properties.
*
* When an output property emits an event, an event handler attached to that event
* in the template is invoked.
*
* The `outputs` property defines a set of `directiveProperty` to `alias`
* configuration:
*
* - `directiveProperty` specifies the component property that emits events.
* - `alias` specifies the DOM property the event handler is attached to.
*
* @usageNotes
*
* ```ts
* @Component({
* selector: 'child-dir',
* outputs: [ 'bankNameChange' ],
* template: `<input (input)="bankNameChange.emit($event.target.value)" />`
* })
* class ChildDir {
* bankNameChange: EventEmitter<string> = new EventEmitter<string>();
* }
*
* @Component({
* selector: 'main',
* template: `
* {{ bankName }} <child-dir (bankNameChange)="onBankNameChange($event)"></child-dir>
* `
* })
* class MainComponent {
* bankName: string;
*
* onBankNameChange(bankName: string) {
* this.bankName = bankName;
* }
* }
* ```
*
*/
outputs?: string[];
/**
* Configures the injector of this
* directive or component with a token
* that maps to a provider of a dependency.
*/
providers?: Provider[];
/**
* Defines the name that can be used in the template to assign this directive to a variable.
*
* @usageNotes
*
* ```ts
* @Directive({
* selector: 'child-dir',
* exportAs: 'child'
* })
* class ChildDir {
* }
*
* @Component({
* selector: 'main',
* template: `<child-dir #c="child"></child-dir>`
* })
* class MainComponent {
* }
* ```
*
*/
exportAs?: string;
/**
* Configures the queries that will be injected into the directive.
*
* Content queries are set before the `ngAfterContentInit` callback is called.
* View queries are set before the `ngAfterViewInit` callback is called.
*
* @usageNotes
*
* The following example shows how queries are defined
* and when their results are available in lifecycle hooks:
*
* ```ts
* @Component({
* selector: 'someDir',
* queries: {
* contentChildren: new ContentChildren(ChildDirective),
* viewChildren: new ViewChildren(ChildDirective)
* },
* template: '<child-directive></child-directive>'
* })
* class SomeDir {
* contentChildren: QueryList<ChildDirective>,
* viewChildren: QueryList<ChildDirective>
*
* ngAfterContentInit() {
* // contentChildren is set
* }
*
* ngAfterViewInit() {
* // viewChildren is set
* }
* }
* ```
*
* @Annotation
*/
queries?: {[key: string]: any};
/**
* Maps class properties to host element bindings for properties,
* attributes, and events, using a set of key-value pairs.
*
* Angular automatically checks host property bindings during change detection.
* If a binding changes, Angular updates the directive's host element.
*
* When the key is a property of the host element, the property value is
* propagated to the specified DOM property.
*
* When the key is a static attribute in the DOM, the attribute value
* is propagated to the specified property in the host element.
*
* For event handling:
* - The key is the DOM event that the directive listens to.
* The global target names that can be used to prefix an event name are
* `document:`, `window:` and `body:`.
*
* - The value is the statement to execute when the event occurs. If the
* statement evaluates to `false`, then `preventDefault` is applied on the DOM
* event. A handler method can refer to the `$event` local variable.
*
*/
host?: {[key: string]: string};
/**
* When present, this directive/component is ignored by the AOT compiler.
* It remains in distributed code, and the JIT compiler attempts to compile it
* at run time, in the browser.
* To ensure the correct behavior, the app must import `@angular/compiler`.
*/
jit?: true;
/**
* Set `standalone` to `false` if you want to import the directive into an NgModule.
*/
standalone?: boolean;
/**
* // TODO(signals): Remove internal and add public documentation
*
* @internal
*/
signals?: boolean;
/**
* Standalone directives that should be applied to the host whenever the directive is matched.
* By default, none of the inputs or outputs of the host directives will be available on the host,
* unless they are specified in the `inputs` or `outputs` properties.
*
* You can additionally alias inputs and outputs by putting a colon and the alias after the
* original input or output name. For example, if a directive applied via `hostDirectives`
* defines an input named `menuDisabled`, you can alias this to `disabled` by adding
* `'menuDisabled: disabled'` as an entry to `inputs`.
*/
hostDirectives?: (
| Type<unknown>
| {
directive: Type<unknown>;
inputs?: string[];
outputs?: string[];
}
)[];
}
/**
* Type of the Directive metadata.
*
* @publicApi
*/
export const Directive: DirectiveDecorator = makeDecorator(
'Directive',
(dir: Directive = {}) => dir,
undefined,
undefined,
(type: Type<any>, meta: Directive) => compileDirective(type, meta),
);
/**
* Component decorator interface
*
* @publicApi
*/
export interface ComponentDecorator {
/**
* Decorator that marks a class as an Angular component and provides configuration
* metadata that determines how the component should be processed,
* instantiated, and used at runtime.
*
* Components are the most basic UI building block of an Angular app.
* An Angular app contains a tree of Angular components.
*
* Angular components are a subset of directives, always associated with a template.
* Unlike other directives, only one component can be instantiated for a given element in a
* template.
*
* Standalone components can be directly imported in any other standalone component or NgModule.
* NgModule based apps on the other hand require components to belong to an NgModule in
* order for them to be available to another component or application. To make a component a
* member of an NgModule, list it in the `declarations` field of the `NgModule` metadata.
*
* Note that, in addition to these options for configuring a directive,
* you can control a component's runtime behavior by implementing
* life-cycle hooks. For more information, see the
* [Lifecycle Hooks](guide/components/lifecycle) guide.
*
* HELPFUL: You may not use this interface to describe a class that is a component. Decorators do not affect the typing of the decorated classes.
* Use `Type<unknown>` instead of `Type<Component>`.
*
* @usageNotes
*
* ### Setting component inputs
*
* The following example creates a component with two data-bound properties,
* specified by the `inputs` value.
*
* {@example core/ts/metadata/directives.ts region='component-input'}
*
*
* ### Setting component outputs
*
* The following example shows two output function that emit on an interval. One
* emits an output every second, while the other emits every five seconds.
*
* {@example core/ts/metadata/directives.ts region='component-output-interval'}
*
* ### Injecting a class with a view provider
*
* The following simple example injects a class into a component
* using the view provider specified in component metadata:
*
* ```ts
* class Greeter {
* greet(name:string) {
* return 'Hello ' + name + '!';
* }
* }
*
* @Directive({
* selector: 'needs-greeter'
* })
* class NeedsGreeter {
* greeter:Greeter;
*
* constructor(greeter:Greeter) {
* this.greeter = greeter;
* }
* }
*
* @Component({
* selector: 'greet',
* viewProviders: [
* Greeter
* ],
* template: `<needs-greeter></needs-greeter>`
* })
* class HelloWorld {
* }
*
* ```
*
* ### Preserving whitespace
*
* Removing whitespace can greatly reduce AOT-generated code size and speed up view creation.
* As of Angular 6, the default for `preserveWhitespaces` is false (whitespace is removed).
* To change the default setting for all components in your application, set
* the `preserveWhitespaces` option of the AOT compiler.
*
* By default, the AOT compiler removes whitespace characters as follows:
* * Trims all whitespaces at the beginning and the end of a template.
* * Removes whitespace-only text nodes. For example,
*
* ```html
* <button>Action 1</button> <button>Action 2</button>
* ```
*
* becomes:
*
* ```html
* <button>Action 1</button><button>Action 2</button>
* ```
*
* * Replaces a series of whitespace characters in text nodes with a single space.
* For example, `<span>\n some text\n</span>` becomes `<span> some text </span>`.
* * Does NOT alter text nodes inside HTML tags such as `<pre>` or `<textarea>`,
* where whitespace characters are significant.
*
* Note that these transformations can influence DOM nodes layout, although impact
* should be minimal.
*
* You can override the default behavior to preserve whitespace characters
* in certain fragments of a template. For example, you can exclude an entire
* DOM sub-tree by using the `ngPreserveWhitespaces` attribute:
*
* ```html
* <div ngPreserveWhitespaces>
* whitespaces are preserved here
* <span> and here </span>
* </div>
* ```
*
* You can force a single space to be preserved in a text node by using `&ngsp;`,
* which is replaced with a space character by Angular's template
* compiler:
*
* ```html
* <a>Spaces</a>&ngsp;<a>between</a>&ngsp;<a>links.</a>
* <!-- compiled to be equivalent to:
* <a>Spaces</a> <a>between</a> <a>links.</a> -->
* ```
*
* Note that sequences of `&ngsp;` are still collapsed to just one space character when
* the `preserveWhitespaces` option is set to `false`.
*
* ```html
* <a>before</a>&ngsp;&ngsp;&ngsp;<a>after</a>
* <!-- compiled to be equivalent to:
* <a>before</a> <a>after</a> -->
* ```
*
* To preserve sequences of whitespace characters, use the
* `ngPreserveWhitespaces` attribute.
*
* @Annotation
*/
(obj: Component): TypeDecorator;
/**
* See the `Component` decorator.
*/
new (obj: Component): Component;
}
/**
* Supplies configuration metadata for an Angular component.
*
* @see [Anatomy of a component](guide/components)
* @see [ChangeDetectionStrategy](guide/components/advanced-configuration#changedetectionstrategy)
* @see [Using the viewProviders array](guide/di/hierarchical-dependency-injection#using-the-viewproviders-array)
* @see [Style scoping](guide/components/styling#style-scoping)
*
* @publicApi
*/
export interface Component extends Directive {
/**
* The change-detection strategy to use for this component.
*
* When a component is instantiated, Angular creates a change detector,
* which is responsible for propagating the component's bindings.
* The strategy is one of:
* - `ChangeDetectionStrategy#OnPush` sets the strategy to `CheckOnce` (on demand).
* - `ChangeDetectionStrategy#Eager` sets the strategy to `CheckAlways`.
*
* NOTE: OnPush is enabled by default.
*/
changeDetection?: ChangeDetectionStrategy;
/**
* Defines the set of injectable objects that are visible to its view DOM children.
* See [example](#injecting-a-class-with-a-view-provider).
*
*/
viewProviders?: Provider[];
/**
* The relative path or absolute URL of a template file for an Angular component.
* If provided, do not supply an inline template using `template`.
*
*/
templateUrl?: string;
/**
* An inline template for an Angular component. If provided,
* do not supply a template file using `templateUrl`.
*
*/
template?: string;
/**
* One relative path or an absolute URL for file containing a CSS stylesheet to use
* in this component.
*/
styleUrl?: string;
/**
* Relative paths or absolute URLs for files containing CSS stylesheets to use in this component.
*/
styleUrls?: string[];
/**
* One or more inline CSS stylesheets to use
* in this component.
*/
styles?: string | string[];
/**
* One or more animation `trigger()` calls, containing
* [`state()`](api/animations/state) and `transition()` definitions.
* See the [Animations guide](guide/animations) and animations API documentation.
*
* @deprecated 20.2 Use `animate.enter` or `animate.leave` instead. Intent to remove in v23
*/
animations?: any[];
/**
* An encapsulation policy for the component's styling.
* Possible values:
* - `ViewEncapsulation.Emulated`: Apply modified component styles in order to emulate
* a native Shadow DOM CSS encapsulation behavior.
* - `ViewEncapsulation.None`: Apply component styles globally without any sort of encapsulation.
* - `ViewEncapsulation.ShadowDom`: Use the browser's native Shadow DOM API to encapsulate styles.
*
* If not supplied, the value is taken from the `CompilerOptions`
* which defaults to `ViewEncapsulation.Emulated`.
*
* If the policy is `ViewEncapsulation.Emulated` and the component has no
* {@link Component#styles styles} nor {@link Component#styleUrls styleUrls},
* the policy is automatically switched to `ViewEncapsulation.None`.
*/
encapsulation?: ViewEncapsulation;
/**
* True to preserve or false to remove potentially superfluous whitespace characters
* from the compiled template. Whitespace characters are those matching the `\s`
* character class in JavaScript regular expressions. Default is false, unless
* overridden in compiler options.
*/
preserveWhitespaces?: boolean;
/**
* Set `standalone` to `false` if you want to import the directive into an NgModule.
*/
standalone?: boolean;
/**
* The imports property specifies the standalone component's template dependencies — those
* directives, components, and pipes that can be used within its template. Standalone components
* can import other standalone components, directives, and pipes as well as existing NgModules.
*
* This property is only available for standalone components - specifying it for components
* declared in an NgModule generates a compilation error.
*/
imports?: (Type<any> | ReadonlyArray<any>)[];
/**
* The foreignImports property specifies components from other frameworks that can be used
* within this component's template.
*
* @internal // 3p-only
*/
foreignImports?: ForeignComponent<any, any>[];
/**
* The `deferredImports` property specifies a standalone component's template dependencies,
* which should be defer-loaded as a part of the `@defer` block. Angular *always* generates
* dynamic imports for such symbols and removes the regular/eager import. Make sure that imports
* which bring symbols used in the `deferredImports` don't contain other symbols.
*
* Note: this is an internal-only field, use regular `@Component.imports` field instead.
* @internal // 3p-only
*/
deferredImports?: {[blockName: string]: (Type<any> | ReadonlyArray<any>)[]};
/**
* The set of schemas that declare elements to be allowed in a standalone component. Elements and
* properties that are neither Angular components nor directives must be declared in a schema.
*
* This property is only available for standalone components - specifying it for components
* declared in an NgModule generates a compilation error.
*/
schemas?: SchemaMetadata[];
}
/**
* Component decorator and metadata.
*
* @Annotation
* @publicApi
*/
export const Component: ComponentDecorator = makeDecorator(
'Component',
(c: Component = {}) => ({changeDetection: ChangeDetectionStrategy.Eager, ...c}),
Directive,
undefined,
(type: Type<any>, meta: Component) => compileComponent(type, meta),
);
/**
* Type of the Pipe decorator / constructor function.
*
* @publicApi
*/
export interface PipeDecorator {
/**
*
* Decorator that marks a class as pipe and supplies configuration metadata.
*
* A pipe class must implement the `PipeTransform` interface.
* For example, if the name is "myPipe", use a template binding expression
* such as the following:
*
* ```html
* {{ exp | myPipe }}
* ```
*
* The result of the expression is passed to the pipe's `transform()` method.
*
* A pipe must belong to an NgModule in order for it to be available
* to a template. To make it a member of an NgModule,
* list it in the `declarations` field of the `NgModule` metadata.
*
* @see [Pipes](/guide/templates/pipes)
*
*/
(obj: Pipe): TypeDecorator;
/**
* See the `Pipe` decorator.
*/
new (obj: Pipe): Pipe;
}
/**
* Type of the Pipe metadata.
*
* @publicApi
*/
export interface Pipe {
/**
* The pipe name to use in template bindings.
* Typically uses lowerCamelCase
* because the name cannot contain hyphens.
*/
name: string;
/**
* When true, the pipe is pure, meaning that the
* `transform()` method is invoked only when its input arguments
* change. Pipes are pure by default.
*
* If the pipe has internal state (that is, the result
* depends on state other than its arguments), set `pure` to false.
* In this case, the pipe is invoked on each change-detection cycle,
* even if the arguments have not changed.
*/
pure?: boolean;
/**
* Angular pipes marked as `standalone` do not need to be declared in an NgModule. Such
* pipes don't depend on any "intermediate context" of an NgModule (ex. configured providers).
*/
standalone?: boolean;
}
/**
* @Annotation
* @publicApi
*/
export const Pipe: PipeDecorator = makeDecorator(
'Pipe',
(p: Pipe) => ({pure: true, ...p}),
undefined,
undefined,
(type: Type<any>, meta: Pipe) => compilePipe(type, meta),
);
/**
* @publicApi
*/
export interface InputDecorator {
/**
* Decorator that marks a class field as an input property and supplies configuration metadata.
* The input property is bound to a DOM property in the template. During change detection,
* Angular automatically updates the data property with the DOM property's value.
*
* @usageNotes
*
* You can supply an optional name to use in templates when the
* component is instantiated, that maps to the
* name of the bound property. By default, the original
* name of the bound property is used for input binding.
*
* The following example creates a component with two input properties,
* one of which is given a special binding name.
*
* ```ts
* import { Component, Input, numberAttribute, booleanAttribute } from '@angular/core';
* @Component({
* selector: 'bank-account',
* template: `
* Bank Name: {{bankName}}
* Account Id: {{id}}
* Account Status: {{status ? 'Active' : 'InActive'}}
* `
* })
* class BankAccount {
* // This property is bound using its original name.
* // Defining argument required as true inside the Input Decorator
* // makes this property declaration as mandatory
* @Input({ required: true }) bankName!: string;
* // Argument alias makes this property value is bound to a different property name
* // when this component is instantiated in a template.
* // Argument transform convert the input value from string to number
* @Input({ alias:'account-id', transform: numberAttribute }) id: number;
* // Argument transform the input value from string to boolean
* @Input({ transform: booleanAttribute }) status: boolean;
* // this property is not bound, and is not automatically updated by Angular
* normalizedBankName: string;
* }
*
* @Component({
* selector: 'app',
* template: `
* <bank-account bankName="RBC" account-id="4747" status="true"></bank-account>
* `
* })
* class App {}
* ```
*
* @see [Input properties](guide/components/inputs)
* @see [Output properties](guide/components/outputs)
*/
(arg?: string | Input): any;
new (arg?: string | Input): any;
}
/**
* Type of metadata for an `Input` property.
*
* @publicApi
*/
export interface Input {
/**
* The name of the DOM property to which the input property is bound.
*/
alias?: string;
/**
* Whether the input is required for the directive to function.
*/
required?: boolean;
/**
* Function with which to transform the input value before assigning it to the directive instance.
*/
transform?: (value: any) => any;
/**
* @internal
*
* Whether the input is a signal input.
*
* This option exists for JIT compatibility. Users are not expected to use this.
* Angular needs a way to capture inputs from classes so that the internal data
* structures can be set up. This needs to happen before the component is instantiated.
* Due to this, for JIT compilation, signal inputs need an additional decorator
* declaring the input. Angular provides a TS transformer to automatically handle this
* for JIT usage (e.g. in tests).
*/
isSignal?: boolean;
}
/**
* @Annotation
* @publicApi
*/
export const Input: InputDecorator = makePropDecorator(
'Input',
(arg?: string | {alias?: string; required?: boolean}) => {
if (!arg) {
return {};
}
return typeof arg === 'string' ? {alias: arg} : arg;
},
);
/**
* Type of the Output decorator / constructor function.
*
* @publicApi
*/
export interface OutputDecorator {
/**
* Decorator that marks a class field as an output property and supplies configuration metadata.
* The DOM property bound to the output property is automatically updated during change detection.
*
* @usageNotes
*
* You can supply an optional name to use in templates when the
* component is instantiated, that maps to the
* name of the bound property. By default, the original
* name of the bound property is used for output binding.
*
* See `Input` decorator for an example of providing a binding name.
*
* @see [Input properties](guide/components/inputs)
* @see [Output properties](guide/components/outputs)
*
*/
(alias?: string): any;
new (alias?: string): any;
}
/**
* Type of the Output metadata.
*
* @publicApi
*/
export interface Output {
/**
* The name of the DOM property to which the output property is bound.
*/
alias?: string;
}
/**
* @Annotation
* @publicApi
*/
export const Output: OutputDecorator = makePropDecorator('Output', (alias?: string) => ({alias}));
/**
* Type of the HostBinding decorator / constructor function.
*
* @publicApi
*/
export interface HostBindingDecorator {
/**
* Decorator that marks a DOM property or an element class, style or attribute as a host-binding
* property and supplies configuration metadata. Angular automatically checks host bindings during
* change detection, and if a binding changes it updates the host element of the directive.
*
* @usageNotes
*
* NOTE: **Always** prefer using the [`host` property](guide/components/host-elements#binding-to-the-host-element) over `@HostBinding`.
* This decorator exist exclusively for backwards compatibility.
*
* The following example creates a directive that sets the `valid` and `invalid`
* class, a style color, and an id on the DOM element that has an `ngModel` directive on it.
*
* ```ts
* @Directive({selector: '[ngModel]'})
* class NgModelStatus {
* constructor(public control: NgModel) {}
* // class bindings
* @HostBinding('class.valid') get valid() { return this.control.valid; }
* @HostBinding('class.invalid') get invalid() { return this.control.invalid; }
*
* // style binding
* @HostBinding('style.color') get color() { return this.control.valid ? 'green': 'red'; }
*
* // style binding also supports a style unit extension
* @HostBinding('style.width.px') @Input() width: number = 500;
*
* // attribute binding
* @HostBinding('attr.aria-required')
* @Input() required: boolean = false;
*
* // property binding
* @HostBinding('id') get id() { return this.control.value?.length ? 'odd': 'even'; }
*
* @Component({
* selector: 'app',
* template: `<input [(ngModel)]="prop">`,
* })
* class App {
* prop;
* }
* ```
*
*/
(hostPropertyName?: string): any;
new (hostPropertyName?: string): any;
}
/**
* Type of the HostBinding metadata.
*
* @publicApi
*/
export interface HostBinding {
/**
* The DOM property that is bound to a data property.
* This field also accepts:
* * classes, prefixed by `class.`
* * styles, prefixed by `style.`
* * attributes, prefixed by `attr.`
*/
hostPropertyName?: string;
}
/**
* @Annotation
* @publicApi
*/
export const HostBinding: HostBindingDecorator = makePropDecorator(
'HostBinding',
(hostPropertyName?: string) => ({hostPropertyName}),
);