@angular/core/src/zone/ng_zone.d.ts

Angular - the core framework

import { EventEmitter } from '../event_emitter';
/**
 * An injectable service for executing work inside or outside of the Angular zone.
 *
 * The most common use of this service is to optimize performance when starting a work consisting of
 * one or more asynchronous tasks that don't require UI updates or error handling to be handled by
 * Angular. Such tasks can be kicked off via {@link #runOutsideAngular} and if needed, these tasks
 * can reenter the Angular zone via {@link #run}.
 *
 * <!-- TODO: add/fix links to:
 *   - docs explaining zones and the use of zones in Angular and change-detection
 *   - link to runOutsideAngular/run (throughout this file!)
 *   -->
 *
 * ### Example
 *
 * ```
 * import {Component, NgZone} from '@angular/core';
 * import {NgIf} from '@angular/common';
 *
 * @Component({
 *   selector: 'ng-zone-demo'.
 *   template: `
 *     <h2>Demo: NgZone</h2>
 *
 *     <p>Progress: {{progress}}%</p>
 *     <p *ngIf="progress >= 100">Done processing {{label}} of Angular zone!</p>
 *
 *     <button (click)="processWithinAngularZone()">Process within Angular zone</button>
 *     <button (click)="processOutsideOfAngularZone()">Process outside of Angular zone</button>
 *   `,
 * })
 * export class NgZoneDemo {
 *   progress: number = 0;
 *   label: string;
 *
 *   constructor(private _ngZone: NgZone) {}
 *
 *   // Loop inside the Angular zone
 *   // so the UI DOES refresh after each setTimeout cycle
 *   processWithinAngularZone() {
 *     this.label = 'inside';
 *     this.progress = 0;
 *     this._increaseProgress(() => console.log('Inside Done!'));
 *   }
 *
 *   // Loop outside of the Angular zone
 *   // so the UI DOES NOT refresh after each setTimeout cycle
 *   processOutsideOfAngularZone() {
 *     this.label = 'outside';
 *     this.progress = 0;
 *     this._ngZone.runOutsideAngular(() => {
 *       this._increaseProgress(() => {
 *       // reenter the Angular zone and display done
 *       this._ngZone.run(() => {console.log('Outside Done!') });
 *     }}));
 *   }
 *
 *   _increaseProgress(doneCallback: () => void) {
 *     this.progress += 1;
 *     console.log(`Current progress: ${this.progress}%`);
 *
 *     if (this.progress < 100) {
 *       window.setTimeout(() => this._increaseProgress(doneCallback)), 10)
 *     } else {
 *       doneCallback();
 *     }
 *   }
 * }
 * ```
 *
 * @experimental
 */
export declare class NgZone {
    readonly hasPendingMicrotasks: boolean;
    readonly hasPendingMacrotasks: boolean;
    /**
     * Whether there are no outstanding microtasks or macrotasks.
     */
    readonly isStable: boolean;
    /**
     * Notifies when code enters Angular Zone. This gets fired first on VM Turn.
     */
    readonly onUnstable: EventEmitter<any>;
    /**
     * Notifies when there is no more microtasks enqueue in the current VM Turn.
     * This is a hint for Angular to do change detection, which may enqueue more microtasks.
     * For this reason this event can fire multiple times per VM Turn.
     */
    readonly onMicrotaskEmpty: EventEmitter<any>;
    /**
     * Notifies when the last `onMicrotaskEmpty` has run and there are no more microtasks, which
     * implies we are about to relinquish VM turn.
     * This event gets called just once.
     */
    readonly onStable: EventEmitter<any>;
    /**
     * Notifies that an error has been delivered.
     */
    readonly onError: EventEmitter<any>;
    constructor({enableLongStackTrace}: {
        enableLongStackTrace?: boolean;
    });
    static isInAngularZone(): boolean;
    static assertInAngularZone(): void;
    static assertNotInAngularZone(): void;
    /**
     * Executes the `fn` function synchronously within the Angular zone and returns value returned by
     * the function.
     *
     * Running functions via `run` allows you to reenter Angular zone from a task that was executed
     * outside of the Angular zone (typically started via {@link #runOutsideAngular}).
     *
     * Any future tasks or microtasks scheduled from within this function will continue executing from
     * within the Angular zone.
     *
     * If a synchronous error happens it will be rethrown and not reported via `onError`.
     */
    run(fn: () => any): any;
    /**
     * Same as `run`, except that synchronous errors are caught and forwarded via `onError` and not
     * rethrown.
     */
    runGuarded(fn: () => any): any;
    /**
     * Executes the `fn` function synchronously in Angular's parent zone and returns value returned by
     * the function.
     *
     * Running functions via {@link #runOutsideAngular} allows you to escape Angular's zone and do
     * work that
     * doesn't trigger Angular change-detection or is subject to Angular's error handling.
     *
     * Any future tasks or microtasks scheduled from within this function will continue executing from
     * outside of the Angular zone.
     *
     * Use {@link #run} to reenter the Angular zone and do work that updates the application model.
     */
    runOutsideAngular(fn: () => any): any;
}