Angular Schematics

Angular Schematics is a tool for generating, modifying, and extending projects that use the Angular framework. It is built on top of the Angular CLI and uses the same syntax and concepts, but adds additional capabilities for generating and modifying files within an Angular project.

Here are some examples of things you can do with Angular Schematics:

  • Generate new components, modules, and services
  • Modify existing files, such as adding new imports or modifying template code
  • Create custom templates for generating files
  • Extend the Angular CLI with your own commands and options

To use Angular Schematics, you will need to install the Angular CLI and create an Angular project. Then, you can use the ng generate command to invoke the Schematics tool and perform various actions on your project.

For example, to generate a new component named "my-component" in your project, you can use the following command:

ng generate component my-component

This will create a new folder for the component, with the following files:

  • my-component.component.ts: The component class file
  • my-component.component.html: The component template file
  • my-component.component.css: The component styles file
  • my-component.component.spec.ts: The component test file

You can also use Schematics to modify existing files. For example, you can use the ng add command to install and configure additional libraries or frameworks, such as Angular Material or NgRx.

ng add @angular/material

This will install the Angular Material library and add the necessary imports and dependencies to your project.

These are just a few examples of what you can do with Angular Schematics. It is a powerful tool for automating and streamlining the development process for Angular projects.

You can use it to perform a wide range of tasks, such as generating new files and modifying existing ones, creating custom templates, and extending the Angular CLI with your own commands and options.

One way to use Angular Schematics is to create custom templates for generating files. This allows you to define your own templates for generating specific types of files, such as components or services, with pre-defined code and configurations.

To create a custom template, you will need to create a Schematics collection and define a schematic for generating the template. A Schematics collection is a package that contains one or more schematics, which are functions that perform specific tasks, such as generating or modifying files.

Here is an example of a simple schematic for generating a component template:

import { Rule, SchematicContext, Tree } from '@angular-devkit/schematics'; 
	
// The function that will be called when the schematic is executed 
export function myTemplate(options: any): 
	Rule { 
		return (tree: Tree, context: SchematicContext) => 
	{ 
	
	// Modify the tree or perform other tasks here 
	tree.create('my-template.component.ts', `import { Component } from '@angular/core'; 
	@Component({ 
		selector: 'my-template', 
		templateUrl: './my-template.component.html', 
		styleUrls: ['./my-template.component.css'] }) 
		
export class MyTemplateComponent { // Add component code here }`); return tree; }; }

This schematic defines a function that generates a new component file with the given options. To use this schematic, you will need to install it in your Angular project and invoke it with the ng generate command.

ng generate my-template

This will create a new component file with the name and code specified in the schematic.

Certainly! Here is an example of a schematic for generating a new component in an Angular project:

import { Rule, SchematicContext, Tree } from '@angular-devkit/schematics'; 

// The function that will be called when the schematic is executed 

export function myComponent(options: any): Rule { 
	return (tree: Tree, context: SchematicContext) => { 
	
	// Define the path for the new component files 
	const path = `/src/app/components/${options.name}`; 
	
	// Create the component class file 
	tree.create(
		`${path}/${options.name}.component.ts`, 
		`import { Component } from '@angular/core'; 
		
		@Component({ 
			selector: '${options.selector}', 
			templateUrl: './${options.name}.component.html', 
			styleUrls: ['./${options.name}.component.css'] 
		}) 
		
		export class ${options.className} { // Add component code here }
	`); 
		
	// Create the component template file 
	tree.create(
		`${path}/${options.name}.component.html`, 
		`<!-- Add component template here -->`
	); 
		
	// Create the component styles file 
	tree.create(
		`${path}/${options.name}.component.css`, 
		`/* Add component styles here */
	`); 
	
	// Create the component test file 
	tree.create(
		`${path}/${options.name}.component.spec.ts`, 
		`import { async, ComponentFixture, TestBed } from '@angular/core/testing'; 
		
		import { ${options.className} } from './${options.name}.component'; 
		describe('${options.className}', () => { let component: ${options.className}; 
		let fixture: ComponentFixture<${options.className}>; 
		beforeEach(async(() => { TestBed.configureTestingModule({ 
			declarations: [ ${options.className} ] }) .compileComponents(); 
		})); 
		
		beforeEach(() => { fixture = TestBed.createComponent(${options.className}); 
			component = fixture.componentInstance; 
			fixture.detectChanges(); 
		}); 
		
		it('should create', () => 
			{ expect(component).toBeTruthy(); }); });`); return tree; }; }

This schematic defines a function that generates a new component with the given options. The options object contains the following properties:

  • name: The name of the component (used to generate the file names and paths)
  • selector: The HTML selector for the component
  • className: The class name for the component

To use this schematic, you will need to install it in your Angular project and invoke it with the ng generate command.

ng generate my-component --name my-component --selector app-my-component --className MyComponent

This will create a new component with the specified name, selector, and class name, and generate the following files:

  • src/app/components/my-component/my-component.component.ts: The component class file
  • src/app/components/my-component/my-component.component.html: The component
  • src/app/components/my-component/my-component.component.css: The component styles file
  • src/app/components/my-component/my-component.component.spec.ts: The component test file

  • Here is the full code for the schematic:

    import { Rule, SchematicContext, Tree } from '@angular-devkit/schematics'; 
	
// The function that will be called when the schematic is executed 
export function myComponent(options: any): Rule { return (tree: Tree, context: SchematicContext) => { 

// Define the path for the new component files 
const path = `/src/app/components/${options.name}`; 

// Create the component class file 
tree.create(
	`${path}/${options.name}.component.ts`, 
	`import { Component } from '@angular/core'; 
	
	@Component({ 
		selector: '${options.selector}', 
		templateUrl: './${options.name}.component.html', 
		styleUrls: ['./${options.name}.component.css'] 
	}) 
	
	export class ${options.className} { // Add component code here }`); 
	
	// Create the component template file 
	tree.create(
		`${path}/${options.name}.component.html`, 
		`<!-- Add component template here -->`
	); 
	
	// Create the component styles file 
	tree.create(
		`${path}/${options.name}.component.css`,
		 `/* Add component styles here */`
	); 
	
	// Create the component test file 
	tree.create(
		`${path}/${options.name}.component.spec.ts`, 
		`import { async, ComponentFixture, TestBed } from '@angular/core/testing'; 
		import { ${options.className} } from './${options.name}.component'; 
		
		describe('${options.className}', () => { 
			let component: ${options.className}; 
			let fixture: ComponentFixture<${options.className}>; beforeEach(async(() => { TestBed.configureTestingModule({ 
			declarations: [ ${options.className} ] }) .compileComponents(); })); 
			
			beforeEach(() => { 
			fixture = TestBed.createComponent(${options.className}); 
			component = fixture.componentInstance; fixture.detectChanges(); 
		}); 
		
		it('should create', () => { 
			expect(component).toBeTruthy(); 
		}); 
	});`
	); 
	return tree; 
}; 
}

    This schematic creates a new component with the specified name, selector, and class name, and generates the necessary files for the component. You can use this schematic to automate the process of creating new components in your Angular project.