@angular/core

FactoryProvider

interface

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

  
    interface FactoryProvider {}

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

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[]

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