👀 Views: 726 💬 Answers: 1 📅 Created: 2025-09-27

angularjs performance profiling JavaScript

I'm trying to implement I tried several approaches but none seem to work. While profiling our AngularJS application (version 1.8.0) in the staging environment, I noticed significant delays during user interactions, particularly when manipulating a large dataset displayed in a table. The application has several nested components, each managing its own scope, and it seems like the $digest cycle is taking longer than expected. I suspect that excessive watchers are the culprit. To identify the issue, I implemented Angular's built-in tools to log the number of watchers on specific components. Here's the code snippet I used: ```javascript $scope.$watchCollection('myData', function(newData) { console.log('Number of watchers:', $scope.$$watchers.length); }); ``` Initially, I tried to optimize data binding by switching from `ng-repeat` to `track by`, thinking it would help reduce the watchers. ```html <tr ng-repeat="item in myData track by item.id"> <td>{{item.name}}</td> <td>{{item.value}}</td> </tr> ``` Despite this, the performance didn't improve significantly. Additionally, using `ng-if` instead of `ng-show` for conditionally displaying elements also failed to yield the expected results. After some analysis, I began to explore the idea of using one-time bindings where applicable, especially for static data. I refactored part of my template: ```html <td>{{::item.name}}</td> ``` However, even after these measures, the UI still feels sluggish. I've also considered implementing `$timeout` to defer some operations, but I'm not sure if that's the right approach. Can anyone share insights or best practices for managing watchers effectively in AngularJS, especially in scenarios like this? Any recommendations for profiling tools to track down these performance issues would also be greatly appreciated. My development environment is Linux. Any examples would be super helpful.