@angular/core

FactoryProvider

interface

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

  
    interface FactoryProvider extends FactorySansProvider {}

Dependencies can also be marked as optional:

Multi-value example

provide

any

An injection token. (Typically an instance of Type or InjectionToken, but can be any).

multi

boolean | undefined

When true, injector returns an array of instances. This is useful to allow multiple providers spread across many files to provide configuration information to a common token.

useFactory

Function

A function to invoke to create a value for this token. The function is invoked with resolved values of tokens in the deps field.

deps

any[] | undefined

A list of tokens to be resolved by the injector. The list of values is then used as arguments to the useFactory function.