| {"version":3,"file":"observers.js","sources":["../../../src/cdk/observers/observe-content.ts"],"sourcesContent":["/**\n * @license\n * Copyright Google LLC All Rights Reserved.\n *\n * Use of this source code is governed by an MIT-style license that can be\n * found in the LICENSE file at https://angular.io/license\n */\n\nimport {coerceBooleanProperty, coerceNumberProperty, coerceElement} from '@angular/cdk/coercion';\nimport {\n AfterContentInit,\n Directive,\n ElementRef,\n EventEmitter,\n Injectable,\n Input,\n NgModule,\n NgZone,\n OnDestroy,\n Output,\n} from '@angular/core';\nimport {Observable, Subject, Subscription, Observer} from 'rxjs';\nimport {debounceTime} from 'rxjs/operators';\n\n/**\n * Factory that creates a new MutationObserver and allows us to stub it out in unit tests.\n * @docs-private\n */\n@Injectable({providedIn: 'root'})\nexport class MutationObserverFactory {\n create(callback: MutationCallback): MutationObserver | null {\n return typeof MutationObserver === 'undefined' ? null : new MutationObserver(callback);\n }\n}\n\n\n/** An injectable service that allows watching elements for changes to their content. */\n@Injectable({providedIn: 'root'})\nexport class ContentObserver implements OnDestroy {\n /** Keeps track of the existing MutationObservers so they can be reused. */\n private _observedElements = new Map<Element, {\n observer: MutationObserver | null,\n stream: Subject<MutationRecord[]>,\n count: number\n }>();\n\n constructor(private _mutationObserverFactory: MutationObserverFactory) {}\n\n ngOnDestroy() {\n this._observedElements.forEach((_, element) => this._cleanupObserver(element));\n }\n\n /**\n * Observe content changes on an element.\n * @param element The element to observe for content changes.\n */\n observe(element: Element): Observable<MutationRecord[]>;\n\n /**\n * Observe content changes on an element.\n * @param element The element to observe for content changes.\n */\n observe(element: ElementRef<Element>): Observable<MutationRecord[]>;\n\n observe(elementOrRef: Element | ElementRef<Element>): Observable<MutationRecord[]> {\n const element = coerceElement(elementOrRef);\n\n return new Observable((observer: Observer<MutationRecord[]>) => {\n const stream = this._observeElement(element);\n const subscription = stream.subscribe(observer);\n\n return () => {\n subscription.unsubscribe();\n this._unobserveElement(element);\n };\n });\n }\n\n /**\n * Observes the given element by using the existing MutationObserver if available, or creating a\n * new one if not.\n */\n private _observeElement(element: Element): Subject<MutationRecord[]> {\n if (!this._observedElements.has(element)) {\n const stream = new Subject<MutationRecord[]>();\n const observer = this._mutationObserverFactory.create(mutations => stream.next(mutations));\n if (observer) {\n observer.observe(element, {\n characterData: true,\n childList: true,\n subtree: true\n });\n }\n this._observedElements.set(element, {observer, stream, count: 1});\n } else {\n this._observedElements.get(element)!.count++;\n }\n return this._observedElements.get(element)!.stream;\n }\n\n /**\n * Un-observes the given element and cleans up the underlying MutationObserver if nobody else is\n * observing this element.\n */\n private _unobserveElement(element: Element) {\n if (this._observedElements.has(element)) {\n this._observedElements.get(element)!.count--;\n if (!this._observedElements.get(element)!.count) {\n this._cleanupObserver(element);\n }\n }\n }\n\n /** Clean up the underlying MutationObserver for the specified element. */\n private _cleanupObserver(element: Element) {\n if (this._observedElements.has(element)) {\n const {observer, stream} = this._observedElements.get(element)!;\n if (observer) {\n observer.disconnect();\n }\n stream.complete();\n this._observedElements.delete(element);\n }\n }\n}\n\n\n/**\n * Directive that triggers a callback whenever the content of\n * its associated element has changed.\n */\n@Directive({\n selector: '[cdkObserveContent]',\n exportAs: 'cdkObserveContent',\n})\nexport class CdkObserveContent implements AfterContentInit, OnDestroy {\n /** Event emitted for each change in the element's content. */\n @Output('cdkObserveContent') event = new EventEmitter<MutationRecord[]>();\n\n /**\n * Whether observing content is disabled. This option can be used\n * to disconnect the underlying MutationObserver until it is needed.\n */\n @Input('cdkObserveContentDisabled')\n get disabled() { return this._disabled; }\n set disabled(value: any) {\n this._disabled = coerceBooleanProperty(value);\n this._disabled ? this._unsubscribe() : this._subscribe();\n }\n private _disabled = false;\n\n /** Debounce interval for emitting the changes. */\n @Input()\n get debounce(): number { return this._debounce; }\n set debounce(value: number) {\n this._debounce = coerceNumberProperty(value);\n this._subscribe();\n }\n private _debounce: number;\n\n private _currentSubscription: Subscription | null = null;\n\n constructor(private _contentObserver: ContentObserver,\n private _elementRef: ElementRef<HTMLElement>,\n private _ngZone: NgZone) {}\n\n ngAfterContentInit() {\n if (!this._currentSubscription && !this.disabled) {\n this._subscribe();\n }\n }\n\n ngOnDestroy() {\n this._unsubscribe();\n }\n\n private _subscribe() {\n this._unsubscribe();\n const stream = this._contentObserver.observe(this._elementRef);\n\n // TODO(mmalerba): We shouldn't be emitting on this @Output() outside the zone.\n // Consider brining it back inside the zone next time we're making breaking changes.\n // Bringing it back inside can cause things like infinite change detection loops and changed\n // after checked errors if people's code isn't handling it properly.\n this._ngZone.runOutsideAngular(() => {\n this._currentSubscription =\n (this.debounce ? stream.pipe(debounceTime(this.debounce)) : stream).subscribe(this.event);\n });\n }\n\n private _unsubscribe() {\n if (this._currentSubscription) {\n this._currentSubscription.unsubscribe();\n }\n }\n}\n\n\n@NgModule({\n exports: [CdkObserveContent],\n declarations: [CdkObserveContent],\n providers: [MutationObserverFactory]\n})\nexport class ObserversModule {}\n"],"names":[],"mappings":";;;;;;;;;;;;;;;;;;;;AA6BA,AAAA,MAAa,uBAAuB,CAApC;;;;;IACE,MAAM,CAAC,QAA0B,EAAnC;QACI,OAAO,OAAO,gBAAgB,KAAK,WAAW,GAAG,IAAI,GAAG,IAAI,gBAAgB,CAAC,QAAQ,CAAC,CAAC;KACxF;;;IAJH,EAAA,IAAA,EAAC,UAAU,EAAX,IAAA,EAAA,CAAY,EAAC,UAAU,EAAE,MAAM,EAAC,EAAhC,EAAA;;;;;;AAUA,AAAA,MAAa,eAAe,CAA5B;;;;IAQE,WAAF,CAAsB,wBAAiD,EAAvE;QAAsB,IAAtB,CAAA,wBAA8C,GAAxB,wBAAwB,CAAyB;;;;QAN7D,IAAV,CAAA,iBAA2B,GAAG,IAAI,GAAG,EAI/B,CAAC;KAEoE;;;;IAEzE,WAAW,GAAb;QACI,IAAI,CAAC,iBAAiB,CAAC,OAAO;;;;;QAAC,CAAC,CAAC,EAAE,OAAO,KAAK,IAAI,CAAC,gBAAgB,CAAC,OAAO,CAAC,EAAC,CAAC;KAChF;;;;;IAcD,OAAO,CAAC,YAA2C,EAArD;;QACA,MAAU,OAAO,GAAG,aAAa,CAAC,YAAY,CAAC,CAA/C;QAEI,OAAO,IAAI,UAAU;;;;QAAC,CAAC,QAAoC,KAA/D;;YACA,MAAY,MAAM,GAAG,IAAI,CAAC,eAAe,CAAC,OAAO,CAAC,CAAlD;;YACA,MAAY,YAAY,GAAG,MAAM,CAAC,SAAS,CAAC,QAAQ,CAAC,CAArD;YAEM;;;YAAO,MAAb;gBACQ,YAAY,CAAC,WAAW,EAAE,CAAC;gBAC3B,IAAI,CAAC,iBAAiB,CAAC,OAAO,CAAC,CAAC;aACjC,EAAC;SACH,EAAC,CAAC;KACJ;;;;;;;;IAMO,eAAe,CAAC,OAAgB,EAA1C;QACI,IAAI,CAAC,IAAI,CAAC,iBAAiB,CAAC,GAAG,CAAC,OAAO,CAAC,EAAE;;YAC9C,MAAY,MAAM,GAAG,IAAI,OAAO,EAAoB,CAApD;;YACA,MAAY,QAAQ,GAAG,IAAI,CAAC,wBAAwB,CAAC,MAAM;;;;YAAC,SAAS,IAAI,MAAM,CAAC,IAAI,CAAC,SAAS,CAAC,EAAC,CAAhG;YACM,IAAI,QAAQ,EAAE;gBACZ,QAAQ,CAAC,OAAO,CAAC,OAAO,EAAE;oBACxB,aAAa,EAAE,IAAI;oBACnB,SAAS,EAAE,IAAI;oBACf,OAAO,EAAE,IAAI;iBACd,CAAC,CAAC;aACJ;YACD,IAAI,CAAC,iBAAiB,CAAC,GAAG,CAAC,OAAO,EAAE,EAAC,QAAQ,EAAE,MAAM,EAAE,KAAK,EAAE,CAAC,EAAC,CAAC,CAAC;SACnE;aAAM;YACL,mBAAA,IAAI,CAAC,iBAAiB,CAAC,GAAG,CAAC,OAAO,CAAC,GAAE,KAAK,EAAE,CAAC;SAC9C;QACD,OAAO,mBAAA,IAAI,CAAC,iBAAiB,CAAC,GAAG,CAAC,OAAO,CAAC,GAAE,MAAM,CAAC;KACpD;;;;;;;;IAMO,iBAAiB,CAAC,OAAgB,EAA5C;QACI,IAAI,IAAI,CAAC,iBAAiB,CAAC,GAAG,CAAC,OAAO,CAAC,EAAE;YACvC,mBAAA,IAAI,CAAC,iBAAiB,CAAC,GAAG,CAAC,OAAO,CAAC,GAAE,KAAK,EAAE,CAAC;YAC7C,IAAI,CAAC,mBAAA,IAAI,CAAC,iBAAiB,CAAC,GAAG,CAAC,OAAO,CAAC,GAAE,KAAK,EAAE;gBAC/C,IAAI,CAAC,gBAAgB,CAAC,OAAO,CAAC,CAAC;aAChC;SACF;KACF;;;;;;;IAGO,gBAAgB,CAAC,OAAgB,EAA3C;QACI,IAAI,IAAI,CAAC,iBAAiB,CAAC,GAAG,CAAC,OAAO,CAAC,EAAE;YAC7C,MAAY,EAAC,QAAQ,EAAE,MAAM,EAAC,sBAAG,IAAI,CAAC,iBAAiB,CAAC,GAAG,CAAC,OAAO,CAAC,EAAC,CAArE;YACM,IAAI,QAAQ,EAAE;gBACZ,QAAQ,CAAC,UAAU,EAAE,CAAC;aACvB;YACD,MAAM,CAAC,QAAQ,EAAE,CAAC;YAClB,IAAI,CAAC,iBAAiB,CAAC,MAAM,CAAC,OAAO,CAAC,CAAC;SACxC;KACF;;;IAtFH,EAAA,IAAA,EAAC,UAAU,EAAX,IAAA,EAAA,CAAY,EAAC,UAAU,EAAE,MAAM,EAAC,EAAhC,EAAA;;;;IASA,EAAA,IAAA,EAAgD,uBAAuB,EAAvE;;;;;;;AAyFA,AAAA,MAAa,iBAAiB,CAA9B;;;;;;IA2BE,WAAF,CAAsB,gBAAiC,EACjC,WAAoC,EACpC,OAAe,EAFrC;QAAsB,IAAtB,CAAA,gBAAsC,GAAhB,gBAAgB,CAAiB;QACjC,IAAtB,CAAA,WAAiC,GAAX,WAAW,CAAyB;QACpC,IAAtB,CAAA,OAA6B,GAAP,OAAO,CAAQ;;;;QA3BN,IAA/B,CAAA,KAAoC,GAAG,IAAI,YAAY,EAAoB,CAAC;QAYlE,IAAV,CAAA,SAAmB,GAAG,KAAK,CAAC;QAWlB,IAAV,CAAA,oBAA8B,GAAwB,IAAI,CAAC;KAIlB;;;;;;IArBvC,IACI,QAAQ,GADd,EACmB,OAAO,IAAI,CAAC,SAAS,CAAC,EAAE;;;;;IACzC,IAAI,QAAQ,CAAC,KAAU,EAAzB;QACI,IAAI,CAAC,SAAS,GAAG,qBAAqB,CAAC,KAAK,CAAC,CAAC;QAC9C,IAAI,CAAC,SAAS,GAAG,IAAI,CAAC,YAAY,EAAE,GAAG,IAAI,CAAC,UAAU,EAAE,CAAC;KAC1D;;;;;IAID,IACI,QAAQ,GADd,EAC2B,OAAO,IAAI,CAAC,SAAS,CAAC,EAAE;;;;;IACjD,IAAI,QAAQ,CAAC,KAAa,EAA5B;QACI,IAAI,CAAC,SAAS,GAAG,oBAAoB,CAAC,KAAK,CAAC,CAAC;QAC7C,IAAI,CAAC,UAAU,EAAE,CAAC;KACnB;;;;IASD,kBAAkB,GAApB;QACI,IAAI,CAAC,IAAI,CAAC,oBAAoB,IAAI,CAAC,IAAI,CAAC,QAAQ,EAAE;YAChD,IAAI,CAAC,UAAU,EAAE,CAAC;SACnB;KACF;;;;IAED,WAAW,GAAb;QACI,IAAI,CAAC,YAAY,EAAE,CAAC;KACrB;;;;;IAEO,UAAU,GAApB;QACI,IAAI,CAAC,YAAY,EAAE,CAAC;;QACxB,MAAU,MAAM,GAAG,IAAI,CAAC,gBAAgB,CAAC,OAAO,CAAC,IAAI,CAAC,WAAW,CAAC,CAAlE;;;;;QAMI,IAAI,CAAC,OAAO,CAAC,iBAAiB;;;QAAC,MAAnC;YACM,IAAI,CAAC,oBAAoB;gBACrB,CAAC,IAAI,CAAC,QAAQ,GAAG,MAAM,CAAC,IAAI,CAAC,YAAY,CAAC,IAAI,CAAC,QAAQ,CAAC,CAAC,GAAG,MAAM,EAAE,SAAS,CAAC,IAAI,CAAC,KAAK,CAAC,CAAC;SAC/F,EAAC,CAAC;KACJ;;;;;IAEO,YAAY,GAAtB;QACI,IAAI,IAAI,CAAC,oBAAoB,EAAE;YAC7B,IAAI,CAAC,oBAAoB,CAAC,WAAW,EAAE,CAAC;SACzC;KACF;;;IA/DH,EAAA,IAAA,EAAC,SAAS,EAAV,IAAA,EAAA,CAAW;gBACT,QAAQ,EAAE,qBAAqB;gBAC/B,QAAQ,EAAE,mBAAmB;aAC9B,EAAD,EAAA;;;;IA4BA,EAAA,IAAA,EAAwC,eAAe,EAAvD;IAtJA,EAAA,IAAA,EAAE,UAAU,EAAZ;IAKA,EAAA,IAAA,EAAE,MAAM,EAAR;;;IAwHA,KAAA,EAAA,CAAA,EAAA,IAAA,EAAG,MAAM,EAAT,IAAA,EAAA,CAAU,mBAAmB,EAA7B,EAAA,CAAA;IAMA,QAAA,EAAA,CAAA,EAAA,IAAA,EAAG,KAAK,EAAR,IAAA,EAAA,CAAS,2BAA2B,EAApC,EAAA,CAAA;IASA,QAAA,EAAA,CAAA,EAAA,IAAA,EAAG,KAAK,EAAR,CAAA;;AAmDA,MAAa,eAAe,CAA5B;;;IALA,EAAA,IAAA,EAAC,QAAQ,EAAT,IAAA,EAAA,CAAU;gBACR,OAAO,EAAE,CAAC,iBAAiB,CAAC;gBAC5B,YAAY,EAAE,CAAC,iBAAiB,CAAC;gBACjC,SAAS,EAAE,CAAC,uBAAuB,CAAC;aACrC,EAAD,EAAA;;;;;;;;;;;;;;;"} |