Implement a delay on $scope.$watch

Question

I was wondering whether or not it is possible to implement a slight delay on $scope.$watch. I have the following which queries the server, so I\'d like to implement a slight del

Answer 1

I like to use Lo-Dash which provides two really useful capabilities: debounce and throttle which does exactly what you want. Let's say you want to make sure it only calls the function once per 150 ms:

function update() {
 $scope.loading = true;
    returnFactory.query($scope.query).then(function (returns) {
        $scope.returns = returns;
        $scope.loading = false;
    });
}

$scope.$watch("query", function () {
   _.throttle(update, 150);
});

The throttle function lets you control when the update function is called (trailing or leading edge).

I use Lo-Dash all the time in my app. It is a must-have library for me... more useful than jQuery. But, you can create a custom build of Lo-Dash which only includes the throttle and debounce functions if you don't want to include the entire library.