How can I generate an event when contents of a Javascript array is modified i.e. an event should be generated when push or pop operations are performed over that particular Javascript array. Basically, I want to track the push, pop operations performed over a particular Javascript array.
Edit :- The solutions which are stated in comments, requires to override the push or pop method. I want to perform it without doing overriding it.
The idea is that Arrays are Objects so you can define properties.
var someArray = []; // a normal array
someArray.push = function() { // this will override the original push method
// custom code here
console.log('pushing something..');
return Array.prototype.push.apply(this, arguments); // original push
};
// now everytime you push something a message will be logged. Change this functionality as you like.
Note: someArray.push() will now be enumerable. If you want to prevent this you can define a 'push' property using Object.property method.
Object.defineProperty(someArray, 'push', {
enumerable: false, // it's false by default anyway
value: function() {
console.log('pushing something..');
return Array.prototype.push.apply(this, arguments);
}
});
I think there is no native way of doing that. This topic was also discussed here and the suggested solution was to implement a wrapper class for your arrays.
Another way would be to only implement a wrapper push function and trigger the event on function call.
