I've struggled for a couple of days with this bug I had in an Angular application, where changing the source of the grid didn't trigger the watch.
Simplified, my code looked like this
var a = [1,2]; var b = a; var c = b; b = [3,4];
Changing b should also change c. But it didn't. The reason why is that, after all the assignments, a, b and c point to the same memory location.
But when I assign a new array to b, ONLY b points to the new memory location. a and c point to the old one.
So, in order for c to point to the same location, I need to change the EXISTING array, not assign a new array to b.
So, after doing:
b.length = 0; //empty the array for(var idx = 0; idx < newArray.length; idx++) b.push(newArray[idx]);
Now ALL 3 variables, a, b and c point to the same location. Angular's watch gets triggered, and everyone is happy :)