Angular: Disable Change Detector for an entire class (service or component)

Question

Is there a way to completely disable Angular\'s change detector if events that normally cause the change detection to run (setTimeout, setInterval, browser events, ajax calls et

Answer 1

One possible solution might be the following @RunOutsideAngular decorator for your service:

declare let Zone: any;

export function RunOutsideAngular(target: any) {
  Object.getOwnPropertyNames(target.prototype)
    .filter(p => typeof target.prototype[p] === 'function')
    .forEach(p => {
      let originalMethod = target.prototype[p];  
      target.prototype[p] = function (...args) {
        let self = this;
        Zone.root.run(() => originalMethod.apply(self, args));
      }
    });

  let ctor: any = function (...args) {
    let self = this;
    return Zone.root.run(() => target.apply(self, args));
  };
  ctor.prototype = target.prototype;
  return ctor;
}

Plunker Example

If you want to disable only setTimeout and setInterval within some class you can patch these functions

function patchTimers(timers: any[]) {
    timers.forEach((timer) => {
        let originalMethod = window[timer];
        window[timer] = function (...args) {
            let self = this;
            if (Zone.current['__runOutsideAngular__'] === true && Zone.current.name === 'angular') {
                Zone.root.run(() => originalMethod.apply(self, args));
            } else {
                originalMethod.apply(this, arguments);
            }
        };
    })
}
patchTimers(['setTimeout', 'setInterval']);

and create decorator like this

export function RunOutsideAngular(target: any) {
    Object.getOwnPropertyNames(target.prototype)
        .filter(p => typeof target.prototype[p] === 'function')
        .forEach(p => {
            let originalMethod = target.prototype[p];
            target.prototype[p] = function (...args) {
                Zone.current['__runOutsideAngular__'] = true;
                originalMethod.apply(this, args);
                delete Zone.current['__runOutsideAngular__'];
            }
        });

    let ctor: any = function (...args) {
        Zone.current['__runOutsideAngular__'] = true;
        let instance = target.apply(this, args);
        delete Zone.current['__runOutsideAngular__'];
        return instance;
    };
    ctor.prototype = target.prototype;
    return ctor;
}

Then you can use it as follows

@RunOutsideAngular
export class Service {
  constructor() {
    setInterval(() => {
      console.log('ctor tick');
    }, 1000);
  }

  run() {
    setTimeout(() => {
      console.log('tick');
    }, 1000);

    setInterval(() => {
      console.log('tick interval');
    }, 1000)
  }
}

Plunker Example