https://github.com/pujansrt/angular-cheatsheet
Commands, Patterns, Common Packages, Tricks and Tips on latest Angular Framework
https://github.com/pujansrt/angular-cheatsheet
Last synced: 22 days ago
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Commands, Patterns, Common Packages, Tricks and Tips on latest Angular Framework
- Host: GitHub
- URL: https://github.com/pujansrt/angular-cheatsheet
- Owner: pujansrt
- License: mit
- Created: 2020-11-15T07:56:33.000Z (over 4 years ago)
- Default Branch: main
- Last Pushed: 2022-03-24T02:24:37.000Z (about 3 years ago)
- Last Synced: 2025-02-13T04:31:27.887Z (3 months ago)
- Homepage:
- Size: 50.8 KB
- Stars: 5
- Watchers: 1
- Forks: 0
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
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README
## Angular Cheatsheet
BASED ON https://angular.io/guide/cheatsheet
```python
npm install --save @angular/cli # install command line interface (CLI) for Angular apps
ng new Todo # Create new Todo project. Generates new Todo folder in current directory
ng serve # serve the app
ng g component my-new-component # Component MyNewComponent will be created and added to app.module.ts
ng g directive my-new-directive # new directive
ng g pipe my-new-pipe
ng g service my-new-service
ng g class my-new-class
ng g interface my-new-interface
ng g enum my-new-enum
ng g module my-module
ng build # build the release
ng build --prod --base-href /aws/
ng build --prod --output-hashing none
ng build --prod --base-href /aws/ --output-path ~/Sites/aws
```
### BOOSTRAPPING
https://angular.io/guide/bootstrapping
https://angular.io/guide/ngmodules
```js
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
// Bootstraps the app, using the root component from the specified NgModule.
platformBrowserDynamic().bootstrapModule(AppModule);
import { NgModule } from '@angular/core';
@NgModule({
declarations: ...,
imports: ...,
exports: ...,
providers: ...,
bootstrap: ...
})
// Defines a module that contains components, directives, pipes, and providers.
class MyModule {}
// List of components, directives, and pipes that belong to this module.
declarations: [MyRedComponent, MyBlueComponent, MyDatePipe]
// List of modules to import into this module. Everything from the imported modules is available to declarations of this module.
imports: [BrowserModule, SomeOtherModule]
// List of components, directives, and pipes visible to modules that import this module.
exports: [MyRedComponent, MyDatePipe]
// List of dependency injection providers visible both to the contents of this module and to importers of this module.
providers: [MyService, { provide: ... }]
// List of components to bootstrap when this module is bootstrapped.
bootstrap: [MyAppComponent]
```
### TEMPLATE SYNTAX
https://angular.io/guide/template-syntax
#### Style
```js
...
// Allows you to assign styles to an HTML element using CSS.
```
#### Main
```js
Hello {{ponyName}}
Employer: {{employer?.companyName}}
...
Card No.: {{cardNumber | myCardNumberFormatter}}
```
#### Loop
##### Table
```js
Name
Index
{{hero.name}}
```
##### Other Loop
```js
{{i + 1}} - {{hero.fullName}}
{{t}}
```
##### Print Items
```js
I am the first item and I am gonna be showed
I am not the first item and I will not show up :(
But I'm gonna be showed as I am the last item :)
```
### BUILT-IN DIRECTIVES
https://angular.io/guide/attribute-directives
```js
import { CommonModule } from '@angular/common';
// Conditionally swaps the contents of the div by selecting one of the embedded templates based on
// the current value of conditionExpression.
...
...
...
```
### FORMS
https://angular.io/guide/forms
```js
// app.module.ts
import { FormsModule } from '@angular/forms';
@NgModule({
declarations: [...],
imports: [
...,
FormsModule,
],
providers: [...],
bootstrap: [AppComponent]
})
// Provides two-way data-binding, parsing, and validation for form controls.
```
### CLASS DECORATORS
```js
import { Directive, ... } from '@angular/core';
@Component({...}) // Declares that a class is a component and provides metadata about the component.
class MyComponent() {}
@Directive({...}) // Declares that a class is a directive and provides metadata about the directive.
class MyDirective() {}
@Pipe({...}) // Declares that a class is a pipe and provides metadata about the pipe.
class MyPipe() {}
@Injectable() // Declares that a class can be injected into the constructor of another class
class MyService() {}
```
### COMPONENT CHANGE DETECTION AND LIFECYCLE HOOKS
```js
// Called before any other lifecycle hook. Avoid any serious work here.
constructor(myService: MyService, ...) { ... }
// Called after every change to input properties and before processing content or child views.
ngOnChanges(changeRecord) { ... }
// Called after the constructor, initializing input properties, and the first call to ngOnChanges.
ngOnInit() { ... }
// Called every time that the input properties of a component or a directive are checked. Use it
// to extend change detection by performing a custom check.
ngDoCheck() { ... }
// Called after ngOnInit when the component's or directive's content has been initialized.
ngAfterContentInit() { ... }
// Called after every check of the component's or directive's content.
ngAfterContentChecked() { ... }
// Called after ngAfterContentInit when the component's views+child views/that a directive has been initialized.
ngAfterViewInit() { ... }
// Called after every check of the component's views and child views / the view that a directive is in.
ngAfterViewChecked() { ... }
// Called once, before the instance is destroyed.
ngOnDestroy() { ... }
```
### DEPENDENCY INJECTION CONFIGURATION
https://angular.io/guide/dependency-injection
```js
// Sets or overrides the provider for MyService to the MyMockService class.
{ provide: MyService, useClass: MyMockService }
// Sets or overrides the provider for MyService to the myFactory factory function.
{ provide: MyService, useFactory: myFactory }
// Sets or overrides the provider for MyValue to the value 41.
{ provide: MyValue, useValue: 41 }
```
### ROUTING AND NAVIGATION
https://angular.io/guide/router
```js
import { Routes, RouterModule, ... } from '@angular/router';
const routes: Routes = [
{ path: '', component: HomeComponent },
{ path: 'path/:routeParam', component: MyComponent },
{ path: 'staticPath', component: ... },
{ path: '**', component: ... },
{ path: 'oldPath', redirectTo: '/staticPath' },
{ path: ..., component: ..., data: { message: 'Custom' } }
]);
// Configures routes for the application. Supports static, parameterized, redirect, and wildcard
// routes. Also supports custom route data and resolve.
const routing = RouterModule.forRoot(routes);
// Marks the location to load the component of the active route.
// Creates a link to a different view based on a route instruction consisting of a route path,
// required and optional parameters, query parameters, and a fragment. To navigate to a root
// route, use the / prefix; for a child route, use the ./prefix; for a sibling or parent, use the
// ../ prefix.
// The provided classes are added to the element when the routerLink becomes the current active
// route.
class CanActivateGuard implements CanActivate {
canActivate(
route: ActivatedRouteSnapshot,
state: RouterStateSnapshot
): Observable|Promise|boolean { ... }
}
// An interface for defining a class that the router should call first to determine if it should
// activate this component. Should return a boolean or an Observable/Promise that resolves to a boolean.
{
path: ...,
canActivate: [CanActivateGuard]
}
class CanDeactivateGuard implements CanDeactivate {
canDeactivate(
component: T,
route: ActivatedRouteSnapshot,
state: RouterStateSnapshot
): Observable|Promise|boolean { ... }
}
// An interface for defining a class that the router should call first to determine if it should
// deactivate this component after a navigation. Should return a boolean or an Observable/Promise
// that resolves to a boolean.
{
path: ...,
canDeactivate: [CanDeactivateGuard]
}
class CanActivateChildGuard implements CanActivateChild {
canActivateChild(
route: ActivatedRouteSnapshot,
state: RouterStateSnapshot
): Observable|Promise|boolean { ... }
}
// An interface for defining a class that the router should call first to determine if it should
// activate the child route. Should return a boolean or an Observable/Promise that resolves to a boolean.
{
path: ...,
canActivateChild: [CanActivateGuard],
children: ...
}
class ResolveGuard implements Resolve {
resolve(
route: ActivatedRouteSnapshot,
state: RouterStateSnapshot
): Observable|Promise|any { ... }
}
// An interface for defining a class that the router should call first to resolve route data before rendering the route. Should return a value or an Observable/Promise that resolves to a value.
{
path: ...,
resolve: [ResolveGuard]
}
class CanLoadGuard implements CanLoad {
canLoad(
route: Route
): Observable|Promise|boolean { ... }
}
// An interface for defining a class that the router should call first to check if the lazy loaded module should be loaded. Should return a boolean or an Observable/Promise that resolves to a boolean.
{
path: ...,
canLoad: [CanLoadGuard],
loadChildren: ...
}
```
## Input and Output
### Input
**Input()** To pass value into child component
```js
// hero-parent.component.ts
import { Component } from '@angular/core';
@Component({
selector: 'app-hero-parent',
template: `
{{master}} controls {{heroes.length}} heroes
`
})
export class HeroParentComponent {
heroes = [
{ name: 'Superman', location: 'Hong Kong' },
{ name: 'Spiderman', location: 'Dallas' },
{ name: 'Ironman', location: 'Delhi' },
];
master = 'Master';
}
```
```js
// hero-child.component.ts
@Component({
selector: 'app-hero-child',
template: `
{{hero.name}} says:
I, {{hero.name}}, am at your service in {{hero.location}}, {{master}}.
`
})
export class HeroChildComponent {
@Input() hero;
@Input() master;
}
```
Output shows when load `` in app.component.html
```html
Master controls 3 heroes
Superman says:
I, Superman, am at your service in Hong Kong, Master
Spiderman says:
I, Spiderman, am at your service in Dallas, Master
Ironman says:
I, Ironman, am at your service in Delhi, Master
```
### Output
**Output()** Emiting event to parent component
```js
import {Component, Input, Output, EventEmitter} from '@angular/core';
@Component({
selector: 'yc',
template: ``
})
export class ChildComponent {
@Output() notifyFromY: EventEmitter = new EventEmitter();
constructor(){}
onNotify(message:string):void {
//console.log(message, new Date());
this.notifyFromY.emit(message + ' Y --->');
}
}
```
### AuthGuard
```js
RouterModule.forRoot([
...,
{ path: 'check-out', component: CheckOutComponent, canActivate: [AuthGuard] },
{ path: 'admin/products/new', component: AdminProductEditComponent, canActivate: [AuthGuard, AdminAuthGuard] },
{ path: 'admin/products/:id', component: AdminProductEditComponent, canActivate: [AuthGuard, AdminAuthGuard] }
]);
```
```js
@Injectable({
providedIn: 'root'
})
export class AuthGuard implements CanActivate {
constructor(public authService: AuthService, public router: Router) {}
canActivate(
next: ActivatedRouteSnapshot,
state: RouterStateSnapshot): Observable | Promise | boolean {
if (this.authService.isLoggedIn !== true) {
this.router.navigate(['login']);
}
return true;
}
}
```
```js
@Injectable({
providedIn: 'root'
})
export class AdminAuthGuard implements CanActivate {
constructor(public authService: AuthService, public router: Router) {
}
canActivate(
next: ActivatedRouteSnapshot,
state: RouterStateSnapshot): Observable | Promise | boolean {
if (this.authService.isLoggedIn !== true) {
this.router.navigate(['login']);
}
if (!this.authService.isAdmin) {
this.router.navigate(['not-found']);
}
return true;
}
}
```