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/Angular

@angular/core

package

Implements Angular's core functionality, low-level services, and utilities.

  • Defines the class infrastructure for components, view hierarchies, change detection, rendering, and event handling.

  • Defines the decorators that supply metadata and context for Angular constructs.

  • Defines infrastructure for dependency injection (DI), internationalization (i18n), and various testing and debugging facilities.

Entry points

Primary

@angular/core

Implements Angular's core functionality, low-level services, and utilities.

Secondary

@angular/core/global

Exposes a set of functions in the global namespace which are useful for debugging the current state of your application. These functions are exposed via the global ng "namespace" variable automatically when you import from @angular/core and run your application in development mode. These functions are not exposed when the application runs in a production mode.

@angular/core/testing

Provides infrastructure for testing Angular core functionality.

Primary entry point exports

NgModules

ApplicationModule

Configures the root injector for an app with providers of @angular/core dependencies that ApplicationRef needs to bootstrap components.

Classes

ApplicationInitStatus

A class that reflects the state of running APP_INITIALIZER functions.

ChangeDetectorRef

Base class that provides change detection functionality. A change-detection tree collects all views that are to be checked for changes. Use the methods to add and remove views from the tree, initiate change-detection, and explicitly mark views as dirty, meaning that they have changed and need to be re-rendered.

Compiler

Low-level service for running the angular compiler during runtime to create ComponentFactorys, which can later be used to create and render a Component instance.

CompilerFactory

A factory for creating a Compiler

ComponentFactory

Base class for a factory that can create a component dynamically. Instantiate a factory for a given type of component with resolveComponentFactory(). Use the resulting ComponentFactory.create() method to create a component of that type.

ComponentFactoryResolver

A simple registry that maps Components to generated ComponentFactory classes that can be used to create instances of components. Use to obtain the factory for a given component type, then use the factory's create() method to create a component of that type.

ComponentRef

Represents a component created by a ComponentFactory. Provides access to the component instance and related objects, and provides the means of destroying the instance.

DebugElement
DebugEventListener
DebugNode
DefaultIterableDiffer

Deprecated: v4.0.0 - Should not be part of public API.

ElementRef

A wrapper around a native element inside of a View.

EmbeddedViewRef

Represents an Angular view in a view container. An embedded view can be referenced from a component other than the hosting component whose template defines it, or it can be defined independently by a TemplateRef.

ErrorHandler

Provides a hook for centralized exception handling.

EventEmitter

Use in components with the @Output directive to emit custom events synchronously or asynchronously, and register handlers for those events by subscribing to an instance.

InjectionToken

Creates a token that can be used in a DI Provider.

Injector

Concrete injectors implement this interface. Injectors are configured with providers that associate dependencies of various types with injection tokens.

IterableDiffers

A repository of different iterable diffing strategies used by NgFor, NgClass, and others.

KeyValueDiffers

A repository of different Map diffing strategies used by NgClass, NgStyle, and others.

ModuleWithComponentFactories

Combination of NgModuleFactory and ComponentFactorys.

NgModuleFactory
NgModuleFactoryLoader

Deprecated: the string form of loadChildren is deprecated, and NgModuleFactoryLoader is part of its implementation. See LoadChildren for more details.

Used to load ng module factories.

NgModuleRef

Represents an instance of an NgModule created by an NgModuleFactory. Provides access to the NgModule instance and related objects.

NgProbeToken

A token for third-party components that can register themselves with NgProbe.

NgZone

An injectable service for executing work inside or outside of the Angular zone.

Query

Base class for query metadata.

QueryList

An unmodifiable list of items that Angular keeps up to date when the state of the application changes.

ReflectiveInjector

Deprecated: from v5 - slow and brings in a lot of code, Use Injector.create instead.

A ReflectiveDependency injection container used for instantiating objects and resolving dependencies.

ReflectiveKey

Deprecated: No replacement

A unique object used for retrieving items from the ReflectiveInjector.

Renderer2

Extend this base class to implement custom rendering. By default, Angular renders a template into DOM. You can use custom rendering to intercept rendering calls, or to render to something other than DOM.

RendererFactory2

Creates and initializes a custom renderer that implements the Renderer2 base class.

ResolvedReflectiveFactory

An internal resolved representation of a factory function created by resolving Provider.

Sanitizer

Sanitizer is used by the views to sanitize potentially dangerous values.

SimpleChange

Represents a basic change from a previous to a new value for a single property on a directive instance. Passed as a value in a SimpleChanges object to the ngOnChanges hook.

SystemJsNgModuleLoader

Deprecated: the string form of loadChildren is deprecated, and SystemJsNgModuleLoader is part of its implementation. See LoadChildren for more details.

NgModuleFactoryLoader that uses SystemJS to load NgModuleFactory

SystemJsNgModuleLoaderConfig

Deprecated: the string form of loadChildren is deprecated, and SystemJsNgModuleLoaderConfig is part of its implementation. See LoadChildren for more details.

Configuration for SystemJsNgModuleLoader. token.

TemplateRef

Represents an embedded template that can be used to instantiate embedded views. To instantiate embedded views based on a template, use the ViewContainerRef method createEmbeddedView().

Testability

The Testability service provides testing hooks that can be accessed from the browser and by services such as Protractor. Each bootstrapped Angular application on the page will have an instance of Testability.

TestabilityRegistry

A global registry of Testability instances for specific elements.

Type

Represents a type that a Component or other object is instances of.

Version

Represents the version of Angular

ViewContainerRef

Represents a container where one or more views can be attached to a component.

ViewRef

Represents an Angular view.

WrappedValue

Deprecated: from v10 stop using. (No replacement, deemed unnecessary.)

Indicates that the result of a Pipe transformation has changed even though the reference has not changed.

Decorators

Attribute

Parameter decorator for a directive constructor that designates a host-element attribute whose value is injected as a constant string literal.

Component

Decorator that marks a class as an Angular component and provides configuration metadata that determines how the component should be processed, instantiated, and used at runtime.

ContentChild

Parameter decorator that configures a content query.

ContentChildren

Parameter decorator that configures a content query.

Directive

Decorator that marks a class as an Angular directive. You can define your own directives to attach custom behavior to elements in the DOM.

Host

Parameter decorator on a view-provider parameter of a class constructor that tells the DI framework to resolve the view by checking injectors of child elements, and stop when reaching the host element of the current component.

HostBinding

Decorator that marks a DOM property as a host-binding property and supplies configuration metadata. Angular automatically checks host property bindings during change detection, and if a binding changes it updates the host element of the directive.

HostListener

Decorator that declares a DOM event to listen for, and provides a handler method to run when that event occurs.

Inject

Parameter decorator on a dependency parameter of a class constructor that specifies a custom provider of the dependency.

Injectable

Decorator that marks a class as available to be provided and injected as a dependency.

Input

Decorator that marks a class field as an input property and supplies configuration metadata. The input property is bound to a DOM property in the template. During change detection, Angular automatically updates the data property with the DOM property's value.

NgModule

Decorator that marks a class as an NgModule and supplies configuration metadata.

Optional

Parameter decorator to be used on constructor parameters, which marks the parameter as being an optional dependency. The DI framework provides null if the dependency is not found.

Output

Decorator that marks a class field as an output property and supplies configuration metadata. The DOM property bound to the output property is automatically updated during change detection.

Pipe

Decorator that marks a class as pipe and supplies configuration metadata.

Self

Parameter decorator to be used on constructor parameters, which tells the DI framework to start dependency resolution from the local injector.

SkipSelf

Parameter decorator to be used on constructor parameters, which tells the DI framework to start dependency resolution from the parent injector. Resolution works upward through the injector hierarchy, so the local injector is not checked for a provider.

ViewChild

Property decorator that configures a view query. The change detector looks for the first element or the directive matching the selector in the view DOM. If the view DOM changes, and a new child matches the selector, the property is updated.

ViewChildren

Parameter decorator that configures a view query.

Functions

asNativeElements
assertPlatform

Checks that there is currently a platform that contains the given token as a provider.

createPlatform

Creates a platform. Platforms must be created on launch using this function.

createPlatformFactory

Creates a factory for a platform. Can be used to provide or override Providers specific to your applciation's runtime needs, such as PLATFORM_INITIALIZER and PLATFORM_ID.

destroyPlatform

Destroys the current Angular platform and all Angular applications on the page. Destroys all modules and listeners registered with the platform.

enableProdMode

Disable Angular's development mode, which turns off assertions and other checks within the framework.

forwardRef

Allows to refer to references which are not yet defined.

getPlatform

Returns the current platform.

isDevMode

Returns whether Angular is in development mode. After called once, the value is locked and won't change any more.

resolveForwardRef

Lazily retrieves the reference value from a forwardRef.

setTestabilityGetter

Set the GetTestability implementation used by the Angular testing framework.

Structures

AbstractType

Represents an abstract class T, if applied to a concrete class it would stop being instantiable.

AfterContentChecked

A lifecycle hook that is called after the default change detector has completed checking all content of a directive.

AfterContentInit

A lifecycle hook that is called after Angular has fully initialized all content of a directive. Define an ngAfterContentInit() method to handle any additional initialization tasks.

AfterViewChecked

A lifecycle hook that is called after the default change detector has completed checking a component's view for changes.

AfterViewInit

A lifecycle hook that is called after Angular has fully initialized a component's view. Define an ngAfterViewInit() method to handle any additional initialization tasks.

ApplicationRef

A reference to an Angular application running on a page.

ChangeDetectionStrategy

The strategy that the default change detector uses to detect changes. When set, takes effect the next time change detection is triggered.

ClassProvider

Configures the Injector to return an instance of useClass for a token.

ClassSansProvider

Configures the Injector to return a value by invoking a useClass function. Base for ClassProvider decorator.

ConstructorProvider

Configures the Injector to return an instance of a token.

ConstructorSansProvider

Configures the Injector to return an instance of a token.

DoBootstrap

Hook for manual bootstrapping of the application instead of using bootstrap array in @NgModule annotation.

DoCheck

A lifecycle hook that invokes a custom change-detection function for a directive, in addition to the check performed by the default change-detector.

ExistingProvider

Configures the Injector to return a value of another useExisting token.

ExistingSansProvider

Configures the Injector to return a value of another useExisting token.

FactoryProvider

Configures the Injector to return a value by invoking a useFactory function.

FactorySansProvider

Configures the Injector to return a value by invoking a useFactory function.

ForwardRefFn

An interface that a function passed into forwardRef has to implement.

GetTestability

Adapter interface for retrieving the Testability service associated for a particular context.

InjectFlags

Injection flags for DI.

InjectableType

A Type which has an InjectableDef static field.

InjectorType

A type which has an InjectorDef static field.

IterableChangeRecord

Record representing the item change information.

IterableChanges

An object describing the changes in the Iterable collection since last time IterableDiffer#diff() was invoked.

IterableDiffer

A strategy for tracking changes over time to an iterable. Used by NgForOf to respond to changes in an iterable by effecting equivalent changes in the DOM.

IterableDifferFactory

Provides a factory for IterableDiffer.

KeyValueChangeRecord

Record representing the item change information.

KeyValueChanges

An object describing the changes in the Map or {[k:string]: string} since last time KeyValueDiffer#diff() was invoked.

KeyValueDiffer

A differ that tracks changes made to an object over time.

KeyValueDifferFactory

Provides a factory for KeyValueDiffer.

MissingTranslationStrategy

Use this enum at bootstrap as an option of bootstrapModule to define the strategy that the compiler should use in case of missing translations:

  • Error: throw if you have missing translations.
  • Warning (default): show a warning in the console and/or shell.
  • Ignore: do nothing.
ModuleWithProviders

A wrapper around an NgModule that associates it with providers. Usage without a generic type is deprecated.

OnChanges

A lifecycle hook that is called when any data-bound property of a directive changes. Define an ngOnChanges() method to handle the changes.

OnDestroy

A lifecycle hook that is called when a directive, pipe, or service is destroyed. Use for any custom cleanup that needs to occur when the instance is destroyed.

OnInit

A lifecycle hook that is called after Angular has initialized all data-bound properties of a directive. Define an ngOnInit() method to handle any additional initialization tasks.

PipeTransform

An interface that is implemented by pipes in order to perform a transformation. Angular invokes the transform method with the value of a binding as the first argument, and any parameters as the second argument in list form.

PlatformRef

The Angular platform is the entry point for Angular on a web page. Each page has exactly one platform. Services (such as reflection) which are common to every Angular application running on the page are bound in its scope. A page's platform is initialized implicitly when a platform is created using a platform factory such as PlatformBrowser, or explicitly by calling the createPlatform() function.

Predicate

A boolean-valued function over a value, possibly including context information regarding that value's position in an array.

RendererStyleFlags2

Flags for renderer-specific style modifiers.

RendererType2

Used by RendererFactory2 to associate custom rendering data and styles with a rendering implementation.

ResolvedReflectiveProvider

An internal resolved representation of a Provider used by the Injector.

SchemaMetadata

A schema definition associated with an NgModule.

SecurityContext

A SecurityContext marks a location that has dangerous security implications, e.g. a DOM property like innerHTML that could cause Cross Site Scripting (XSS) security bugs when improperly handled.

SimpleChanges

A hashtable of changes represented by SimpleChange objects stored at the declared property name they belong to on a Directive or Component. This is the type passed to the ngOnChanges hook.

StaticClassProvider

Configures the Injector to return an instance of useClass for a token.

StaticClassSansProvider

Configures the Injector to return an instance of useClass for a token. Base for StaticClassProvider decorator.

TrackByFunction

An optional function passed into the NgForOf directive that defines how to track changes for items in an iterable. The function takes the iteration index and item ID. When supplied, Angular tracks changes by the return value of the function.

TypeDecorator

An interface implemented by all Angular type decorators, which allows them to be used as decorators as well as Angular syntax.

TypeProvider

Configures the Injector to return an instance of Type when `Type' is used as the token.

ValueProvider

Configures the Injector to return a value for a token.

ValueSansProvider

Configures the Injector to return a value for a token. Base for ValueProvider decorator.

ViewEncapsulation

Defines template and style encapsulation options available for Component's Component.

Types

ANALYZE_FOR_ENTRY_COMPONENTS

Deprecated: Since 9.0.0. With Ivy, this property is no longer necessary.

A DI token that you can use to create a virtual provider that will populate the entryComponents field of components and NgModules based on its useValue property value. All components that are referenced in the useValue value (either directly or in a nested array or map) are added to the entryComponents property.

APP_BOOTSTRAP_LISTENER

A DI token that provides a set of callbacks to be called for every component that is bootstrapped.

APP_ID

A DI token representing a unique string ID, used primarily for prefixing application attributes and CSS styles when ViewEncapsulation.Emulated is being used.

APP_INITIALIZER

A DI token that you can use to provide one or more initialization functions.

COMPILER_OPTIONS

Token to provide CompilerOptions in the platform injector.

CUSTOM_ELEMENTS_SCHEMA

Defines a schema that allows an NgModule to contain the following:

  • Non-Angular elements named with dash case (-).
  • Element properties named with dash case (-). Dash case is the naming convention for custom elements.
CompilerOptions

Options for creating a compiler

DEFAULT_CURRENCY_CODE

Provide this token to set the default currency code your application uses for CurrencyPipe when there is no currency code passed into it. This is only used by CurrencyPipe and has no relation to locale currency. Defaults to USD if not configured.

INJECTOR

An InjectionToken that gets the current Injector for createInjector()-style injectors.

InjectableProvider

Injectable providers used in @Injectable decorator.

LOCALE_ID

Provide this token to set the locale of your application. It is used for i18n extraction, by i18n pipes (DatePipe, I18nPluralPipe, CurrencyPipe, DecimalPipe and PercentPipe) and by ICU expressions.

NO_ERRORS_SCHEMA

Defines a schema that allows any property on any element.

NgIterable

A type describing supported iterable types.

PACKAGE_ROOT_URL

A DI token that indicates the root directory of the application

PLATFORM_ID

A token that indicates an opaque platform ID.

PLATFORM_INITIALIZER

A function that is executed when a platform is initialized.

Provider

Describes how the Injector should be configured.

StaticProvider

Describes how an Injector should be configured as static (that is, without reflection). A static provider provides tokens to an injector for various types of dependencies.

TRANSLATIONS

Use this token at bootstrap to provide the content of your translation file (xtb, xlf or xlf2) when you want to translate your application in another language.

TRANSLATIONS_FORMAT

Provide this token at bootstrap to set the format of your TRANSLATIONS: xtb, xlf or xlf2.

defineInjectable

Deprecated: in v8, delete after v10. This API should be used only be generated code, and that code should now use ɵɵdefineInjectable instead.

getDebugNode
getModuleFactory

Returns the NgModuleFactory with the given id, if it exists and has been loaded. Factories for modules that do not specify an id cannot be retrieved. Throws if the module cannot be found.

inject

Injects a token from the currently active injector.

platformCore

This platform has to be included in any other platform

© 2010–2020 Google, Inc.
Licensed under the Creative Commons Attribution License 4.0.
https://angular.io/api/core