The document provides an introduction to Angular Schematics, covering their purpose, creation, and implementation. It explains how to create a schematic, manipulate template files, and utilize a template expression language. Additionally, it addresses the integration of schematics with the Angular CLI and offers guidance on publishing and securing Angular applications.

1. A Gentle Introduction to Angular Schematics
June 13, 2019
Matt Raible | @mraible
Photo by Joseph Barrientos unsplash.com/photos/Ji_G7Bu1MoM

2. Blogger on raibledesigns.com and
developer.okta.com/blog
Web Developer and Java Champion
Father, Husband, Skier, Mountain
Biker, Whitewater Rafter
Open Source Connoisseur
Hi, I’m Matt Raible!
Bus Lover
Okta Developer Advocate

5. developer.okta.com

6. Agenda
1. What are Angular Schematics?
2. Create and Test a Schematic
3. Schematic Templates
4. Template Expression Language
5. OpenID Connect Authentication
6. Schematics for React, Vue, and Ionic

7. What are Angular Schematics?

8. Create a Schematic
$ npm i -g @angular-devkit/schematics-cli
$ schematics blank —-name=my-component
CREATE /my-component/README.md (639 bytes)
CREATE /my-component/.gitignore (191 bytes)
CREATE /my-component/.npmignore (64 bytes)
CREATE /my-component/package.json (539 bytes)
CREATE /my-component/tsconfig.json (656 bytes)
CREATE /my-component/src/collection.json (231 bytes)
CREATE /my-component/src/my-component/index.ts (318 bytes)
CREATE /my-component/src/my-component/index_spec.ts (474 bytes)

9. Project metadata: collection.json
{
"$schema": "../node_modules/@angular-devkit/schematics/collection-schema.json",
"schematics": {
"my-component": {
"description": "A blank schematic.",
"factory": "./my-component/index#myComponent"
}
}

10. Factory function: index.ts
import { Rule, SchematicContext, Tree } from '@angular-devkit/schematics';
export function myComponent(_options: any): Rule {
return (tree: Tree, _context: SchematicContext) => {
return tree;
};
}

11. Unit test: index_spec.ts
import { Tree } from '@angular-devkit/schematics';
import { SchematicTestRunner } from '@angular-devkit/schematics/testing';
import * as path from 'path';
const collectionPath = path.join(__dirname, '../collection.json');
describe('my-component', () => {
it('works', () => {
const runner = new SchematicTestRunner('schematics', collectionPath);
const tree = runner.runSchematic('my-component', {}, Tree.empty());
expect(tree.files).toEqual([]);
});
});

12. Schematic Templates

13. Copy and Manipulate Templates: directory structure
$ tree .
src/my-component/
├── files
│ └── src
│ └── app
│ ├── app.component.html
│ └── app.component.ts
├── index.ts
└── index_spec.ts

14. Copy and Manipulate Templates: app.component.ts
import { Component } from '@angular/core';
@Component({
selector: 'app-root',
templateUrl: './app.component.html',
styleUrls: ['./app.component.css']
})
export class AppComponent {
name = '<%= name %>';
}
src/my-component/files/src/app/app.component.ts

15. Copy and Manipulate Templates: app.component.html
src/my-component/files/src/app/app.component.html
<div style="text-align:center">
<h1>
Hello, {{ name }}
</h1>
</div>
<router-outlet></router-outlet>

16. Copy and Manipulate Templates: schema.json
{
"$schema": "http://json-schema.org/schema",
"id": "SchematicsMyComponent",
"title": "My Component Schema",
"type": "object",
"properties": {
"name": {
"type": "string",
"description": "Your Name",
"x-prompt": "What is your name?"
}
},
"required": ["name"]
}

17. Copy and Manipulate Templates: collection.json
{
"$schema": "../node_modules/@angular-devkit/schematics/collection-schema.json",
"schematics": {
"my-component": {
"description": "A blank schematic.",
"factory": "./my-component/index#myComponent",
"schema": "./my-component/schema.json"
}
}
}

18. Copy and Manipulate Templates: index.ts
export function myComponent(_options: any): Rule {
return (tree: Tree, _context: SchematicContext) => {
setupOptions(tree, _options);
const movePath = normalize(_options.path + '/');
const templateSource = apply(url('./files/src'), [
template({..._options}),
move(movePath),
// fix for https://github.com/angular/angular-cli/issues/11337
forEach((fileEntry: FileEntry) => {
if (tree.exists(fileEntry.path)) {
tree.overwrite(fileEntry.path, fileEntry.content);
}
return fileEntry;
}),
]);
const rule = mergeWith(templateSource, MergeStrategy.Overwrite);
return rule(tree, _context);
};
}

19. Copy and Manipulate Templates: setupOptions()
export function setupOptions(host: Tree, options: any): Tree {
const workspace = getWorkspace(host);
if (!options.project) {
options.project = Object.keys(workspace.projects)[0];
}
const project = workspace.projects[options.project];
options.path = join(normalize(project.root), 'src');
return host;
}

20. Copy and Manipulate Templates: index_spec.ts
beforeEach(() => {
appTree = schematicRunner.runExternalSchematic(
'@schematics/angular', 'workspace', workspaceOptions);
appTree = schematicRunner.runExternalSchematic(
'@schematics/angular', 'application', appOptions, appTree);
});
it('works', () => {
const runner = new SchematicTestRunner('schematics', collectionPath);
runner.runSchematicAsync(
'my-component', schemaOptions, appTree).toPromise().then(tree => {
const appComponent = tree.readContent(
‘/projects/schematest/src/app/app.component.ts');
expect(appComponent).toContain(`name = '${schemaOptions.name}'`);
});
});

21. Run Your Schematic with Angular CLI
$ npm pack
$ ng new my-test-app --routing --style css
$ cd my-test-app
$ npm install ../my-component/my-component-0.0.0.tgz
$ ng g my-component:my-component

22. Publish Your Schematic to npm
!22
By default, .npmignore ignores all TypeScript files
Modify .npmignore so it doesn't exclude your template files!
Run npm publish

23. Add Support for ng add with Angular CLI
!23
{
"$schema": "../node_modules/@angular-devkit/schematics/collection-schema.json",
"schematics": {
"my-component": {
"description": "A blank schematic.",
"factory": "./my-component/index#myComponent",
"schema": "./my-component/schema.json"
},
"ng-add": {
"factory": "./ng-add/index",
"description": "Add schematic",
"schema": "./my-component/schema.json"
}
}
}

24. Add Support for ng add with Angular CLI
!24
import { chain, Rule, schematic, SchematicContext, Tree, }
from '@angular-devkit/schematics';
export default function (options: any): Rule {
return (host: Tree, context: SchematicContext) => {
return chain([
schematic('my-component', options)
])(host, context);
};
}

25. Template Expression Language
Placeholder Description
<%= expression %>
Replaced with the result of the call of the given expression. This only supports
direct expressions, no structural (for/if/...) JavaScript.
<%- expression %>
Same as above, but the value of the result will be escaped for HTML when
inserted (i.e. replacing '<' with '<')
<% inline code %>
Inserts the given code into the template structure, allowing to insert structural
JavaScript.
<%# text %> A comment, which gets entirely dropped.
https://www.npmjs.com/package/@angular-devkit/schematics#content-templating

26. Example Template Code
import { Injectable } from '@angular/core';
<% if (platform === 'cordova') { %>
import { CordovaBrowser } from ‘ionic-appauth/lib/cordova';
<% } else { %>
import { CapacitorBrowser } from ‘ionic-appauth/lib/capacitor';
<% } %>
@Injectable({
providedIn: 'root'
})
export class BrowserService extends
<%= (platform === 'cordova') ? 'CordovaBrowser' : 'CapacitorBrowser' %> {
}

27. Secure Your Angular App in Minutes!
$ ng new my-secure-app --routing
$ cd my-secure-app
// create a SPA app on Okta, copy settings
$ ng add @oktadev/schematics

30. git clone https://github.com/oktadeveloper/okta-spring-webflux-react-
example.git
Blog, Screencast, and Source Code
https://developer.okta.com/blog/2019/02/13/angular-schematics

31. Thanks!
Keep in Touch
raibledesigns.com
@mraible
Presentations
speakerdeck.com/mraible
Code
github.com/oktadeveloper
developer.okta.com

32. developer.okta.com