How to Keep your Angular Data-Flow Tidy and Efficient

Developing large-scale Angular applications can feel like trying to ride a bicycle with your eyes closed and both hands tied behind your back.

The data flow in an Angular application can be extremely complex, especially when dealing with bidirectional data binding, asynchronous updates, forms, and routing.

The key to managing this complexity is to write clear and concise code that’s easy to read and understand. Whether you’re building an enterprise application or a simple web app, this is crucial.

In this tutorial, we’ll go over some best practices to help you make sure your application follows the Angular way and doesn’t leak state between components or do unnecessary work when handling view changes.

This will help you create complex Angular applications that are easily digestible and maintainable by other developers on your team. Let’s get started!

What You'll Learn

In this post, we'll explore some best practices for keeping your data flow tidy and efficient in Angular applications. We'll cover topics like component communication, data binding, and more.

By the end of this post, you'll have a better understanding of how to keep your data flowing smoothly in Angular apps.

Use Built-in Components Whenever Possible

Angular offers a wide array of built-in components that you can use in your apps. These components are designed to be efficient and easy to use, so take advantage of them when you can.

Built-in components can help reduce the amount of code you have to write, making your app more efficient overall. In addition, using built-in components can help keep your data flow tidy by reducing the potential for errors.

One common error developers make is forgetting to add an event listener on an input control after they’ve updated its value with a model update.

For example, built-in form validation components automatically implement this check for you, greatly reducing this type of error.  

Finally, with built-in components, it’s easier to share updates across different parts of your app since they all use the same APIs.

Use Pipes to Filter, Not Just Transform

Pipes are a great way to filter data in Angular. By using pipes, you can declaratively specify how you want your data to be transformed without having to write code in the component class.

You can learn how to use pipes to filter by playing with the following GitHub code . In the code below we are creating a custom filter pipe:

import { Pipe, PipeTransform } from '@angular/core';
import { User } from './model';

@Pipe({
  name: 'filter',
  pure: false,
})
export class FilterPipe implements PipeTransform {
  transform(value: User[], filterString: string, property: string): User[] {
    console.log('pipe run');
    if (value.length === 0 || !filterString) {
      return value;
    }
    let filteredUsers: User[] = [];
    for (let user of value) {
      if (user[property].toLowerCase().includes(filterString.toLowerCase())) {
        filteredUsers.push(user);
      }
    }
    return filteredUsers;
  }
}

This makes your code more readable and easier to maintain. Plus, it's easy to unit test pipes, so you can be confident that they're doing what you expect.

Consider Using Redux

Redux is a great way to manage data in Angular applications. It helps keep your code organized and tidy and can make debugging and testing much easier.

Redux is also easy to use with other libraries and frameworks, so you can get started quickly.

If you want to learn the basics of Redux, here's a helpful beginner-friendly guide.

Take Advantage of Dependency Injection

Angular's dependency injection system is one of its greatest features, making it easy to modularization and reuse code.

When using Angular services, it's best to keep them lean and focused on a single task. This will help maintain a tidy data flow and avoid code duplication.

To create an injectable service, use the following command:

ng generate service workers/worker

import { Injectable } from '@angular/core';

@Injectable({
  providedIn: 'root'
})
export class WorkerService {

  constructor() { }
}

The @Injectable() decorator tells Angular that this class can be used in the DI system.

Two-Way Bindings Hurt Readability and Maintainability

While two-way bindings are very convenient, they can quickly make your code base a mess. When you have too many two-way bindings, it becomes difficult to track the flow of data through your app. This can lead to unexpected bugs and hard-to-find errors.

Example of two-way binding

<input [(ngModel)]="data"  type="text">
  
<hr>
  
<h3> Learn coding from {{data}}</h3>

import { Component } from "@angular/core";
  
@Component({
  selector: "my-app",
  templateUrl: "./app.component.html",
})
export class AppComponent {
  data = "FreeCodeCamp";
}

You will get the following result from the code above

Two-way binding is a combination of square brackets and parentheses. This syntax combines the property binding brackets, [], with the event binding parentheses ().

Use one-way binding instead

To keep your data flow tidy and efficient, use one-way bindings whenever possible. One-way bindings make it explicit where data is coming from and going to, which makes it much easier to reason about your code.

Example of one-way binding

<button (click)="myFunction()">Alert</button>

import { Component } from '@angular/core';

@Component({
  selector: 'my-app',

  template: `<button (click)='myFunction()' >alert me</button>`,
})
export class AppComponent {
  myFunction(): void {
    alert('Show alert!');
  }
}

When you run the above code, you will see an alert button. When you click that button, it will invoke the component's myFunction() method. This will then execute the alert() method, displaying an alert box with the text Show alert as shown in the following example from the code above.

Write Testable Code

When you're writing code, always keep in mind how easy or difficult it will be to test.  

In general, try to make your code as modular as possible so that you can easily isolate and test individual pieces.

Write unit tests for as much of your code as possible. This will help ensure that your code is working as intended and will catch any errors early on.

Conclusion

There are many ways to keep your data flow organized in an Angular application. The key is to find what works best for you and your team and to be consistent with it.

By following these best practices, you can ensure that your application runs smoothly and efficiently.