Custom Builders in Angular

Introduction

Angular's custom builders allow developers to extend the build process, enabling the creation of tailored solutions for specific project needs. Builders are part of Angular's CLI and can be used to customize the build and serve processes.

What is a Builder?

A builder is a class that implements the Builder interface. It is responsible for defining how a specific command works in the Angular CLI. Builders can be used to run tasks such as building, serving, and testing Angular applications.

Creating a Custom Builder

To create a custom builder, follow these steps:

1. Generate a new builder project
2. Implement the Builder interface
3. Define the builder's schema
4. Export the builder class

Step 1: Generate a New Builder Project

ng generate builder custom-builder --project=my-project

Step 2: Implement the Builder Interface

Create a class that implements the Builder interface:

import { BuilderContext, BuilderOutput, createBuilder } from '@angular-devkit/architect';

            export class MyCustomBuilder {
                async run(builderConfig: any, context: BuilderContext): Promise {
                    // Custom build logic here
                    return { success: true };
                }
            }

            export default createBuilder(MyCustomBuilder);

Step 3: Define the Builder's Schema

Define the schema for your builder to specify the options it accepts:

{
                "$schema": "http://json-schema.org/draft-07/schema#",
                "type": "object",
                "properties": {
                    "option1": {
                        "type": "string"
                    },
                    "option2": {
                        "type": "boolean"
                    }
                }
            }

Using the Custom Builder

To use the custom builder, reference it in your angular.json file:

{
                "projects": {
                    "my-project": {
                        "architect": {
                            "build": {
                                "builder": "my-project:custom-builder",
                                "options": {
                                    "option1": "value",
                                    "option2": true
                                }
                            }
                        }
                    }
                }
            }

Best Practices

• Keep your custom builders focused on a single responsibility.
• Document your builder's options and usage clearly.
• Test your builders thoroughly to ensure reliability.
• Consider performance implications when implementing custom logic.

FAQ