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extensions.view() function

Inject a ContextView for extensions of the extension point. The view can then be listened on events such as bind, unbind, or refresh to react on changes of extensions.

Signature:

function view(extensionPointName?: string, metadata?: InjectionMetadata): (target: Object, member: string | undefined, methodDescriptorOrParameterIndex?: number | TypedPropertyDescriptor<any> | undefined) => void;

Parameters

Parameter Type Description
extensionPointName string _(Optional)_ Name of the extension point. If not supplied, we use the `name` tag from the extension point binding or the class name of the extension point class. If a class needs to inject extensions from multiple extension points, use different `extensionPointName` for different types of extensions.
metadata [InjectionMetadata](/doc/en/lb4/apidocs.context.injectionmetadata.html) _(Optional)_ Optional injection metadata

Returns:

(target: Object, member: string | undefined, methodDescriptorOrParameterIndex?: number | TypedPropertyDescriptor<any> | undefined) => void

Example

import {extensionPoint, extensions} from '@loopback/core';

@extensionPoint(GREETER_EXTENSION_POINT_NAME)
export class GreetingService {
 constructor(
   @extensions.view() // Inject a context view for extensions of the extension point
   private greetersView: ContextView<Greeter>,
   // ...
) {
  // ...
}