typedi/types/interfaces/handler.interface.d.ts

Dependency injection for TypeScript.

import { ContainerInstance } from '../container-instance.class';
import { Constructable } from '../types/constructable.type';
/**
 * Used to register special "handler" which will be executed on a service class during its initialization.
 * It can be used to create custom decorators and set/replace service class properties and constructor parameters.
 */
export interface Handler<T = unknown> {
    /**
     * Service object used to apply handler to.
     */
    object: Constructable<T>;
    /**
     * Class property name to set/replace value of.
     * Used if handler is applied on a class property.
     */
    propertyName?: string;
    /**
     * Parameter index to set/replace value of.
     * Used if handler is applied on a constructor parameter.
     */
    index?: number;
    /**
     * Factory function that produces value that will be set to class property or constructor parameter.
     * Accepts container instance which requested the value.
     */
    value: (container: ContainerInstance) => any;
}