@angular/core

What is @angular/core?

The @angular/core package is a fundamental part of Angular, a popular front-end web application platform. It provides the critical runtime parts of the Angular framework, including the component decorator, directives, dependency injection, and the core Angular APIs necessary for building dynamic single-page web applications.

What are @angular/core's main functionalities?

Components

Components are the building blocks of Angular applications. They control a patch of screen called a view. The @Component decorator indicates that the class immediately below it is a component and provides metadata about the component.

"@Component({ selector: 'app-root', templateUrl: './app.component.html', styleUrls: ['./app.component.css'] }) export class AppComponent { title = 'My Angular App'; }"

Dependency Injection

Dependency Injection (DI) is a design pattern used in Angular to make components or classes dependent on interfaces rather than concrete implementations. This improves modularity and testability.

"constructor(private myService: MyService) {}"

Directives

Directives are classes that add additional behavior to elements in your Angular applications. With Angular's built-in directives, you can manage forms, lists, styles, and what users see.

"@Directive({ selector: '[appHighlight]' }) export class HighlightDirective { constructor(el: ElementRef) { el.nativeElement.style.backgroundColor = 'yellow'; } }"

Other packages similar to @angular/core

react

React is a popular JavaScript library for building user interfaces. It focuses on a component-based architecture similar to Angular but uses a different syntax and design philosophy. React emphasizes a one-way data flow and virtual DOM for efficient rendering.

vue

Vue.js is a progressive JavaScript framework used for building UIs and single-page applications. It is designed from the ground up to be incrementally adoptable. Vue also focuses on the ViewModel part of the MVVM pattern and employs a reactive and composable data model.

README

Angular

The sources for this package are in the main Angular repo. Please file issues and pull requests against that repo.

License: MIT

Changelog

14.1.0 (2022-07-20)

Deprecations

core

• The createNgModuleRef is deprecated in favor of newly added createNgModule one.
• The bit field signature of inject() has been deprecated, in favor of the new options object. Correspondingly, InjectFlags is deprecated as well.

animations

| Commit | Type | Description | | -- | -- | -- | | 55308f2df5 | feat | add provideAnimations() and provideNoopAnimations() functions (#46793) |

common

| Commit | Type | Description | | -- | -- | -- | | 4a2e7335b1 | feat | make the CommonModule pipes standalone (#46401) | | a7597dd080 | feat | make the CommonModule directives standalone (#46469) |

compiler

| Commit | Type | Description | | -- | -- | -- | | 33ce3883a5 | feat | Add extended diagnostic to warn when missing let on ngForOf (#46683) | | 6f11a58040 | feat | Add extended diagnostic to warn when text attributes are intended to be bindings (#46161) | | 9e836c232f | feat | warn when style suffixes are used with attribute bindings (#46651) |

compiler-cli

| Commit | Type | Description | | -- | -- | -- | | 93c65e7b14 | feat | add extended diagnostic for non-nullable optional chains (#46686) | | 131d029da1 | feat | detect missing control flow directive imports in standalone components (#46146) | | 6b8e60c06a | fix | improve the missingControlFlowDirective message (#46846) |

core

| Commit | Type | Description | | -- | -- | -- | | e8e8e5f171 | feat | add createComponent function | | b5153814af | feat | add reflectComponentType function | | 96c6139c9a | feat | add ability to set inputs on ComponentRef (#46641) | | a6d5fe202c | feat | alias createNgModuleRef as createNgModule (#46789) | | 71e606d3c3 | feat | expose EnvironmentInjector on ApplicationRef (#46665) | | 19e6d9ccd3 | feat | import AsyncStackTaggingZone if available (#46693) | | a7a14df5f8 | feat | introduce EnvironmentInjector.runInContext API (#46653) | | fa52b6e906 | feat | options object to supersede bit flags for inject() (#46649) | | af20112222 | feat | support the descendants option for ContentChild queries (#46638) | | 945a3ad359 | fix | Fix runInContext for NgModuleRef injector (#46877) | | bb7c80477b | fix | make parent injector argument required in createEnvironmentInjector (#46397) |

http

| Commit | Type | Description | | -- | -- | -- | | 82acbf919b | feat | improve error message for nullish header (#46059) |

router

| Commit | Type | Description | | -- | -- | -- | | 53ca936366 | feat | Add ability to create UrlTree from any ActivatedRouteSnapshot (#45877) | | de058bba99 | feat | Add CanMatch guard to control whether a Route should match (#46021) | | 6c1357dd7d | feat | Add stable cancelation code to NavigationCancel event (#46675) | | a4ce273e50 | feat | Add the target RouterStateSnapshot to NavigationError (#46731) | | abe3759e24 | fix | allow to return UrlTree from CanMatchFn (#46455) | | e8c7dd10e9 | fix | Ensure APP_INITIALIZER of enabledBlocking option completes (#46026) | | ce20ed067f | fix | Ensure Route injector is created before running CanMatch guards (#46394) | | 6a7b818d94 | fix | Ensure target RouterStateSnapshot is defined in NavigationError (#46842) | | f94c6f433d | fix | Expose CanMatchFn as public API (#46394) | | e8ae0fe3e9 | fix | Fix cancelation code for canLoad rejections (#46752) |

upgrade

| Commit | Type | Description | | -- | -- | -- | | e9cb0454dc | feat | more closely align UpgradeModule#bootstrap() with angular.bootstrap() (#46214) |

Special Thanks

AleksanderBodurri, Alex Rickabaugh, Andrew Kushnir, Andrew Scott, Cédric Exbrayat, Dmitrij Kuba, Dylan Hunn, George Kalpakas, Jessica Janiuk, JiaLiPassion, Joey Perrott, John Vandenberg, JoostK, Keith Li, Or'el Ben-Ya'ir, Paul Gschwendtner, Pawel Kozlowski, SyedAhm3r, arturovt, mariu, markostanimirovic and mgechev

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