Making an Angular application is not enough. Keeping the code simple and well-maintained is equally important. For doing so, you need to stick to some of the Angular best practices. Not does it only helps in making the application cleaner but also boosts the performance of the same.
Angular boasts charting on the list of top 10 web development frameworks in 2018 as the leading front-end framework. Though Angular is one of the leading web application frameworks, it can also be used for building native mobile and desktop applications.
Considering the popularity and importance that Angular has accumulated, now is the best time to learn Angular if you haven’t done it already. Anyways, if you are already developing apps using Angular then must know how to do it better to remain competitive in the rapidly-changing realm of programming.
As such, we are here to share with you some of the best Angular practices suggested by experts. In order to make the most out of this article, you need to have at least a basic understanding of Angular. Considering you have that, let’s advance to the list of 12 best practices for Angular development.
Angular Best Practices
1. Add Caching Mechanisms
Simply, having a caching mechanism in place avoids unwanted API calls. Responses from some of the API calls don’t change at all. In such scenarios, adding a caching mechanism allows for storing the specific value from the API.
Adding caching mechanisms ensures that the same information is not downloaded time and over again. Moreover, making the API calls only when required and avoiding duplication results in a speed boost for the application. This is because there is no need to wait for the network.
2. Benefit from Lazy Loading
Lazy loading is loading something only when it is required. Whenever possible, try to lazy load the modules in the application. The benefit is twofold. First, it reduces the size of the application and second, as only the module that is required is loaded and not the unrequired ones, application boot time improves.
3. Deploy the Right Flattering Operator
Instead of using a multitude of operators when a single operator can suffice reduces the code size. As different types of operators handle observables in different ways, deploying the incorrect operator might lead to unwelcome application behavior.
Therefore, it is important to use the right flattering operator, such as concatMap and mergeMap, while dealing with observables.
4. Don’t Forget to Make Use of Angular CLI
It is highly recommended to make use of the Angular CLI while developing an Angular project. There are several reasons for this, including a boost in productivity. Angular CLI flaunts an enormous set of commands for completing a number of tasks.
Not only the Angular CLI creates components faster but also automatically references the same into their own modules. Moreover, it ensures compliance with the naming convention so that you don’t have to worry about doing it on your own.
5. Don’t Miss Out a Chance to Use Lifecycle Hooks
Whenever possible, use lifecycle hooks. Any component has a lifecycle, which is managed by Angular. Angular creates, renders, creates children, and renders children of components. Further, it checks when a component’s data-bound properties change and penultimately destroys it before finally removing the same from the DOM.
Lifecycle hooks provide the visibility into such key life moments as well as the ability to act when they occur. Some of the lifecycle hooks and their desirable uses include:
- ngOnChanges () – Used for executing logic inside child components prompted by the modification of decorator parameters
- ngOnDestroy () – Used for the need to perform a cleanup of resources when the component is destroyed
- ngOnInit () – Used when some data is required to be fetched from a database as soon as the component is instantiated
6. Ensure Using Lint Rules
In order to avoid doing something that can potentially lead to the rise of some issue later, Angular have lint rules. When a lint rule is in place and you do something wrong, an error will quickly pop-up and save the day for you. You can easily configure various lint rules in the tslint.json file.
Using lint rules in the code enforces consistency in the application as well as enhances readability. Some of the lint rules even come equipped with fixes for resolving the very issues that they correspond to. Moreover, you can write your own lint rules using TSQuery.
7. Isolate API Hacks
Several Angular APIs are plagued by bugs and hence, require fixes. However, it is better to isolate API hacks in one place rather than adding them to the components where they are required. The API hacks can be isolated in a service and used from the component.
But, why should you do it? Because doing so keep the hacks stay closer to the API. In addition to having all the hacks at one place, which makes fixing them easier and convenient, the action reduces the total code that is dealing with the unhacked code.
8. Keep your Application DRY (Do not Repeat Yourself)
Ensure that the same code is not copied in multiple sections of the complete codebase. In some cases, it might be required to change some logic in a particular code section. However, having identical code jotted down in multiple locations means that the change needs to be made at each and every section.
In addition to being a redundant job, this can lead to potential bug occurrences. Having a specific code at only one location not only makes the testing process easier but also improves application speed and performance.
9. Switch to HttpClient from HttpModule
Past Angular 4.3, there is a better way for handling HTTP requests via the HttpClient library. Although the HttpModule library is adequate for handling HTTP requests, it is highly recommended to make a switch to the HttpClient.
This is because aside from all the functionality, using HttpClient brings a number of benefits to the table. For instance, the HttpErrorResponse class in the HttpClient library facilitates error handling. Additionally, HttpClient grants access to interceptors, which allow intercepting HTTP requests, and offers the ability to listen to progress events.
10. Unsubscribe from Observables
While subscribing to observables, ensure that appropriate unsubscribes to the same are also made. As the observable stream is left open, such as after a component is destroyed or the user has navigated to some other page, not unsubscribing from observables might lead to undesired memory leaks.
So, how to unsubscribe from observables? Simple, by using operators such as take and takeUntil. Formulating a lint rule for the detection of observables that aren’t unsubscribed is highly recommended.
11. Use The trackBy Function
Using the trackBy function with the ngFor directive for looping over an array in templates return a unique identifier for each item in the array. When an array is changed, Angular re-renders the complete DOM tree. However, this isn’t the case when using the trackBy function.
The trackBy function allows Angular to know those specific elements that have changed. Hence, it will only make DOM changes for that particular element or set of elements.
12. When Using RxJs Operators, Use Pipeable Operators
This enables benefitting from the tree-shakeable ability of pipeable operators. Simply, it means that rather than the entire code, only the code that is necessary for execution will be included when these operators are imported. Moreover, another advantage is that it makes the identification of unused operators in the files easier.
Let’s Wrap it Up!
Developing applications is a craft and there’s always some room for improvement. Adhering to the aforementioned Angular best practices will make your Angular application development life easier. The less buggy your Angular application is, the better is the chances for performance and productivity to mushroom.
The official Angular style guide is very important for any web developer looking to champion in the craft of Angular development. If you haven’t gone through it yet, now might be a good time to do so. Check it here!