Editing Angular (section)

===Angular Framework Modules===
* BrowserModule
* Core
** @Component
* [[Angular#FormsModule|Template Driven Forms (FormsModule)]]
* [[Angular#HTTPModule|HTTPModule]]
* [[Angular#Reactive_Forms|Reactive Forms (ReactiveFormsModule)]]
* NgModule

* see https://angular-training-guide.rangle.io/forms

=====Template Driven Forms=====
 import {FormsModule} from "@angular/forms";

=====Reactive Forms=====
* see [https://angular.io/guide/reactive-forms official documentation]
* example see <code>menu.component.ts</code> and <code>menu.component.html</code> or <code>configuration.component</code>
 import {ReactiveFormsModule} from "@angular/forms";
** <code>[formGroup]</code> directive
** <code>FormBuilder.group()</code>
** <code>setValue() or patchValue()</code>
** subscribe if needed

====HTTPModule====
* usage
 import { HttpClientModule } from '@angular/common/http';
 import { HttpClient } from '@angular/common/http';
 import { Observable, throwError } from 'rxjs';
 import { catchError, retry } from 'rxjs/operators';
* there are multiple overloads of <code>get()</code>
* observables in general can emit multiple values but an observable returned by the get() method only emits once
* All [[JavaScript/JScript#RxJs|observables]] returned from HttpClient methods are cold by design. Calling <code>subscribe()</code> triggers execution of the observable and causes HttpClient to compose and send the HTTP request to the server.
* '''Completion''' or '''Error''' are mutually exclusive.
* resources
** https://www.techiediaries.com/angular-11-tutorial-example-rest-crud-http-get-httpclient/