Performance tuning is an important aspect of any web application, and Angular is no exception. In this article, we will explore various techniques and strategies for Angular performance tuning that can help developers to improve the performance of the app. By following the tips and best practices outlined in this article, you can ensure that your Angular application is running smoothly and efficiently, providing a better user experience for your users.
Though Angular is popular for its features like easy to learn, easy to implement, used for building SPAs, etc. But when the matter is of developing complex apps, Angular can sometimes face performance glitches. So, here are some best practices that will help you with the situation of Angular performance tuning. Let’s begin with the article then!
Angular Performance Tuning techniques
Here’s the list of seven different tips and strategies that developers can use for perfect angular app performance optimization:
- OnPush change detection strategy
- Controlling Change Detection
- Split your application into lazy-loaded modules.
- Local Change Detection
- Design for immutability
- Lazy Loading
- Trackby
Let’s discuss these strategies in detail.
OnPush change detection strategy
The OnPush change detection strategy is a way of optimizing the performance of an Angular application by reducing the number of times the change detection cycle is run. This is accomplished by setting the change detection strategy for a component to OnPush, which means that the component’s view will only be updated if an input reference changes or an event is emitted by one of the component’s child components.
By default, the change detection cycle in Angular runs every time there is an event, a setTimeout or setInterval callback, or a user interaction with the application. This can lead to performance issues if the application has a lot of components or if the change detection cycle is running too frequently.
Using the OnPush change detection strategy can help improve the performance of your Angular application by reducing the number of times the change detection cycle is run. This can be especially useful if you have components that do not need to update very often, as it will prevent the change detection cycle from running unnecessarily.
Controlling Change Detection
There are several ways to control change detection in an Angular application:
- Manually triggering change detection: You can manually trigger the change detection cycle by calling the markForCheck() method on the ChangeDetectorRef service. This can be useful if you need to update a component’s view outside of the normal change detection cycle.
- Disabling change detection: You can disable change detection for a component by calling the detach() method on the ChangeDetectorRef service. This can be useful if you want to optimise performance by preventing the change detection cycle from running for a particular component. However, it is important to note that this should be used with caution, as it can lead to issues if the component’s view is not properly updated.
- Using observables: You can use observables to control change detection by subscribing to an observable in the component and using the async pipe in the template. This will cause the component’s view to be updated whenever the observable emits a new value.
Split your application into lazy-loaded modules
Lazy loading is a technique that involves splitting your application into smaller, self-contained modules that can be loaded on demand. This can help improve the performance of your application by reducing the initial load time, as the browser only needs to load the code that is required for the current view.
To split your application into lazy-loaded modules in Angular, you can use the Angular router’s loadChildren property. This property allows you to specify the path to a module that should be lazy loaded when the route is activated.
This strategy can help improve the performance of your Angular application by reducing the initial load time and allowing the browser to load only the code that is needed for the current view. It is especially useful for applications with many modules or large modules that are not needed immediately.
Local Change Detection
Local change detection is a technique that can be used to optimize the performance of an Angular application by limiting the scope of the change detection cycle to specific components or groups of components. This can help improve the performance of your application by reducing the number of components that need to be checked during the change detection cycle, which can be especially useful if you have components that do not need to update very often.
To use local change detection, you can use the ChangeDetectorRef service, which provides methods for triggering the change detection cycle and controlling the change detection process.
It is important to use local change detection carefully, as it can lead to performance issues if it is overused or used incorrectly. For example, if you are using local change detection for a component that does need to update frequently, it can result in the component’s view not being updated as frequently as needed. In these cases, it may be necessary to use a different change detection strategy or to manually trigger the change detection cycle.
Design for immutability
Designing for immutability is a technique that can be used to optimize the performance of an Angular application by minimizing the number of changes that need to be detected during the change detection cycle.
In Angular, the change detection cycle checks for changes in the component’s data and updates the component’s view accordingly. If the data being tracked by the change detection cycle is constantly changing, it can lead to performance issues, as the change detection cycle will need to run more frequently to keep the view up to date.
One way to minimize the number of changes being tracked is to design your data structures and application logic to be immutable. Immutable data structures are data structures that cannot be modified once they are created, which means that any changes to the data must be made by creating a new data structure.
By using immutable data structures and designing your application logic to make use of them, you can help minimize the number of changes being tracked by the change detection cycle and improve the performance of your Angular application.
Lazy Loading
Lazy loading is a technique that involves splitting your application into smaller, self-contained modules that can be loaded on demand. This can help improve the performance of your application by reducing the initial load time, as the browser only needs to load the code that is required for the current view.
To implement lazy loading in Angular, you can use the Angular router’s loadChildren property. This property allows you to specify the path to a module that should be lazy loaded when the route is activated.
Trackby
The trackBy function is a way of optimizing the performance of an Angular application when rendering lists of items. It is used in conjunction with the ngFor directive to improve the performance of list rendering by telling Angular how to track changes to items in the list.
This function allows you to specify a unique identifier for each item in the list, which Angular can use to track changes to the items more efficiently. This can help improve the performance of your application by reducing the number of DOM elements that need to be created and destroyed when the list is rendered.
Final Words
In conclusion, optimizing the performance of an Angular application is an important aspect of web development. By following best practices and using the various techniques and strategies discussed in this article, you can ensure that your Angular application is running smoothly and efficiently.