Hope this helps.ĭo share your bag of tips and tricks in the comments section. For things that don’t work well in the Angular context like heavy DOM manipulation, consider using Javascript using a directives link function. Go outside AngularNot everything needs to be Angular. Unbind function.var unregisterFn = $scope.$watch(‘name’, function()
Remove or disable watchers as soon as possible using the.Decrease the number of watchers by avoiding long lists with pagination or infinite scroll.So here are a few things you can do to improve performance: When a $watch is called on a scope value, or value is bound from the DOM with interpolation, ng-repeat, ng-switch, and ng-if, or any other DOM attribute/element, a function gets added to the $$watchers array of the innermost scope. Newcomers to Angular are surprised by the number of watchers as they don’t realize the implicit watcher Angular adds. The rule of thumb is, at around 2000 expressions a page begins to lag in performance. Angular performance is greatly impacted by the number of watcher expressions and the complexity of expressions. The number of watchers, time taken by the watch expression, and the scope in which the loop runs are important. So, the time taken by the digest loop has a direct impact on the performance. This is a multi-pass evaluation to account for values changed in the loop itself. Anytime a value changes, all watchers tied to the scope are evaluated.
If they are not already familiar with this, a quick primer here.Let us recall a couple of facts. Before we begin a good understanding of how Angular implements 2-way binding via its dirty checking mechanism in the digest loop is imperative to understanding many of the performance strategies. Implement all the YSlow principles.Now that you have taken care of all that, let’s look at Angular-specific items. Take care of non-Angular performance items before tackling Angular.įor instance, fix your APIs. Is it Angular, really? Before we blame Angular, let’s make sure the problem is not elsewhere. But for most users, this will be the parts of the page they consider most important. By definition it is highly subjective – some users may think that the page is loaded just because the initial furniture appears. The perceived page performance is how long the user thinks the major elements of the page took to load. In UI, perceived performance is more important than actual performance. When setting goals, instead of focussing just on raw times, do consider perceived performance. Once you measure and understand your current Angular performance, plan your goals. But beware its a bit slow and doesn’t handle large applications well. Pay attention to the Models and Performance tab. This is from the Angular team that helps in profiling and debugging. Here you can see digest cycle timings, ng-repeat bottlenecks etc. For Angular related timing, use the “Flame chart”. The chrome profiler output is very noisy. Tracks resource loading, javascript parsing, style calculation, and repainting. See exactly what your application does in a given timeframe. Premature optimization is the root of all evil – Donald Knuth. So here is the latest on how to get the best Angular performance and tips to learning Angular faster!Īs with any performance exercise, don’t start anything without profiling. Also, some of the advice out there on tuning Angular is out-dated after the 1.3/4 release. Having built many complex front-ends with Angular, I wanted to share a few things we learned in the trenches. While some of them are justified, a lot can be done to make Angular UI peppy. With the advent of Angular 2 and React, there is a lot of backlash against Angular on performance.
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