@angular/cdk
Version:
Angular Material Component Development Kit
211 lines (208 loc) • 9.55 kB
JavaScript
import * as i0 from '@angular/core';
import { Injectable, inject, NgZone, ElementRef, EventEmitter, booleanAttribute, Directive, Output, Input, NgModule } from '@angular/core';
import { Observable, Subject } from 'rxjs';
import { map, filter, debounceTime } from 'rxjs/operators';
import { c as coerceNumberProperty, a as coerceElement } from './element-x4z00URv.mjs';
// Angular may add, remove, or edit comment nodes during change detection. We don't care about
// these changes because they don't affect the user-preceived content, and worse it can cause
// infinite change detection cycles where the change detection updates a comment, triggering the
// MutationObserver, triggering another change detection and kicking the cycle off again.
function shouldIgnoreRecord(record) {
// Ignore changes to comment text.
if (record.type === 'characterData' && record.target instanceof Comment) {
return true;
}
// Ignore addition / removal of comments.
if (record.type === 'childList') {
for (let i = 0; i < record.addedNodes.length; i++) {
if (!(record.addedNodes[i] instanceof Comment)) {
return false;
}
}
for (let i = 0; i < record.removedNodes.length; i++) {
if (!(record.removedNodes[i] instanceof Comment)) {
return false;
}
}
return true;
}
// Observe everything else.
return false;
}
/**
* Factory that creates a new MutationObserver and allows us to stub it out in unit tests.
* @docs-private
*/
class MutationObserverFactory {
create(callback) {
return typeof MutationObserver === 'undefined' ? null : new MutationObserver(callback);
}
static ɵfac = i0.ɵɵngDeclareFactory({ minVersion: "12.0.0", version: "19.2.6", ngImport: i0, type: MutationObserverFactory, deps: [], target: i0.ɵɵFactoryTarget.Injectable });
static ɵprov = i0.ɵɵngDeclareInjectable({ minVersion: "12.0.0", version: "19.2.6", ngImport: i0, type: MutationObserverFactory, providedIn: 'root' });
}
i0.ɵɵngDeclareClassMetadata({ minVersion: "12.0.0", version: "19.2.6", ngImport: i0, type: MutationObserverFactory, decorators: [{
type: Injectable,
args: [{ providedIn: 'root' }]
}] });
/** An injectable service that allows watching elements for changes to their content. */
class ContentObserver {
_mutationObserverFactory = inject(MutationObserverFactory);
/** Keeps track of the existing MutationObservers so they can be reused. */
_observedElements = new Map();
_ngZone = inject(NgZone);
constructor() { }
ngOnDestroy() {
this._observedElements.forEach((_, element) => this._cleanupObserver(element));
}
observe(elementOrRef) {
const element = coerceElement(elementOrRef);
return new Observable((observer) => {
const stream = this._observeElement(element);
const subscription = stream
.pipe(map(records => records.filter(record => !shouldIgnoreRecord(record))), filter(records => !!records.length))
.subscribe(records => {
this._ngZone.run(() => {
observer.next(records);
});
});
return () => {
subscription.unsubscribe();
this._unobserveElement(element);
};
});
}
/**
* Observes the given element by using the existing MutationObserver if available, or creating a
* new one if not.
*/
_observeElement(element) {
return this._ngZone.runOutsideAngular(() => {
if (!this._observedElements.has(element)) {
const stream = new Subject();
const observer = this._mutationObserverFactory.create(mutations => stream.next(mutations));
if (observer) {
observer.observe(element, {
characterData: true,
childList: true,
subtree: true,
});
}
this._observedElements.set(element, { observer, stream, count: 1 });
}
else {
this._observedElements.get(element).count++;
}
return this._observedElements.get(element).stream;
});
}
/**
* Un-observes the given element and cleans up the underlying MutationObserver if nobody else is
* observing this element.
*/
_unobserveElement(element) {
if (this._observedElements.has(element)) {
this._observedElements.get(element).count--;
if (!this._observedElements.get(element).count) {
this._cleanupObserver(element);
}
}
}
/** Clean up the underlying MutationObserver for the specified element. */
_cleanupObserver(element) {
if (this._observedElements.has(element)) {
const { observer, stream } = this._observedElements.get(element);
if (observer) {
observer.disconnect();
}
stream.complete();
this._observedElements.delete(element);
}
}
static ɵfac = i0.ɵɵngDeclareFactory({ minVersion: "12.0.0", version: "19.2.6", ngImport: i0, type: ContentObserver, deps: [], target: i0.ɵɵFactoryTarget.Injectable });
static ɵprov = i0.ɵɵngDeclareInjectable({ minVersion: "12.0.0", version: "19.2.6", ngImport: i0, type: ContentObserver, providedIn: 'root' });
}
i0.ɵɵngDeclareClassMetadata({ minVersion: "12.0.0", version: "19.2.6", ngImport: i0, type: ContentObserver, decorators: [{
type: Injectable,
args: [{ providedIn: 'root' }]
}], ctorParameters: () => [] });
/**
* Directive that triggers a callback whenever the content of
* its associated element has changed.
*/
class CdkObserveContent {
_contentObserver = inject(ContentObserver);
_elementRef = inject(ElementRef);
/** Event emitted for each change in the element's content. */
event = new EventEmitter();
/**
* Whether observing content is disabled. This option can be used
* to disconnect the underlying MutationObserver until it is needed.
*/
get disabled() {
return this._disabled;
}
set disabled(value) {
this._disabled = value;
this._disabled ? this._unsubscribe() : this._subscribe();
}
_disabled = false;
/** Debounce interval for emitting the changes. */
get debounce() {
return this._debounce;
}
set debounce(value) {
this._debounce = coerceNumberProperty(value);
this._subscribe();
}
_debounce;
_currentSubscription = null;
constructor() { }
ngAfterContentInit() {
if (!this._currentSubscription && !this.disabled) {
this._subscribe();
}
}
ngOnDestroy() {
this._unsubscribe();
}
_subscribe() {
this._unsubscribe();
const stream = this._contentObserver.observe(this._elementRef);
this._currentSubscription = (this.debounce ? stream.pipe(debounceTime(this.debounce)) : stream).subscribe(this.event);
}
_unsubscribe() {
this._currentSubscription?.unsubscribe();
}
static ɵfac = i0.ɵɵngDeclareFactory({ minVersion: "12.0.0", version: "19.2.6", ngImport: i0, type: CdkObserveContent, deps: [], target: i0.ɵɵFactoryTarget.Directive });
static ɵdir = i0.ɵɵngDeclareDirective({ minVersion: "16.1.0", version: "19.2.6", type: CdkObserveContent, isStandalone: true, selector: "[cdkObserveContent]", inputs: { disabled: ["cdkObserveContentDisabled", "disabled", booleanAttribute], debounce: "debounce" }, outputs: { event: "cdkObserveContent" }, exportAs: ["cdkObserveContent"], ngImport: i0 });
}
i0.ɵɵngDeclareClassMetadata({ minVersion: "12.0.0", version: "19.2.6", ngImport: i0, type: CdkObserveContent, decorators: [{
type: Directive,
args: [{
selector: '[cdkObserveContent]',
exportAs: 'cdkObserveContent',
}]
}], ctorParameters: () => [], propDecorators: { event: [{
type: Output,
args: ['cdkObserveContent']
}], disabled: [{
type: Input,
args: [{ alias: 'cdkObserveContentDisabled', transform: booleanAttribute }]
}], debounce: [{
type: Input
}] } });
class ObserversModule {
static ɵfac = i0.ɵɵngDeclareFactory({ minVersion: "12.0.0", version: "19.2.6", ngImport: i0, type: ObserversModule, deps: [], target: i0.ɵɵFactoryTarget.NgModule });
static ɵmod = i0.ɵɵngDeclareNgModule({ minVersion: "14.0.0", version: "19.2.6", ngImport: i0, type: ObserversModule, imports: [CdkObserveContent], exports: [CdkObserveContent] });
static ɵinj = i0.ɵɵngDeclareInjector({ minVersion: "12.0.0", version: "19.2.6", ngImport: i0, type: ObserversModule, providers: [MutationObserverFactory] });
}
i0.ɵɵngDeclareClassMetadata({ minVersion: "12.0.0", version: "19.2.6", ngImport: i0, type: ObserversModule, decorators: [{
type: NgModule,
args: [{
imports: [CdkObserveContent],
exports: [CdkObserveContent],
providers: [MutationObserverFactory],
}]
}] });
export { CdkObserveContent, ContentObserver, MutationObserverFactory, ObserversModule };
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