Angular2 watch object/array changes (Angular2 final >= 2.1.1)

Question

I\'d like to watch an object/array, which ca be edited by a service or by a controllers routine. I thought that an Observable could watch an object/array.

My implem

Answer 1

In the import section:

import { DoCheck, KeyValueDiffers, KeyValueChangeRecord } from '@angular/core';

Adding the 'KeyValueDiffers' injector:

private _differ: any;    

constructor(private _differs: KeyValueDiffers) {
    this._differ = _differs.find({}).create();
}

Finally track changes:

ngDoCheck() {
    const change = this._differ.diff(this.Your_Object_To_Track);
    if (change) {
        change.forEachChangedItem(
            (record: KeyValueChangeRecord) => {
                console.log(record.key + ': ' +  record.previousValue + '=>' + record.currentValue) });

        change.forEachRemovedItem(                
                (record: KeyValueChangeRecord) => {
                    console.log(record.key + ': ' +  record.previousValue + '=>' + record.currentValue) });

        change.forEachAddedItem((record: KeyValueChangeRecord) => {
                console.log(record.key + ': ' +  record.previousValue + '=>' + record.currentValue) });
    }
}