sourceafIoc::Override.fan

** Use in 'AppModule' classes to override a service builder.
@Js
facet class Override {
    
    ** The service Id (or override Id) to be overridden. 
    ** 
    ** Use either this or 'serviceType', not both.
    const Str?  serviceId   := null

    ** The type of the service to be overridden.
    **  
    ** Use either this or 'serviceId', not both.
    const Type? serviceType := null
    
    ** Override the list of scopes the service may be created in.
    const Str[]? scopes     := null

    ** Override the list of service ID aliases.
    const Str[]? aliases    := null

    ** Override the list of service types aliases.
    const Type[]? aliasTypes    := null

    ** An optional reference to this override, so others may override this override.
    ** 3rd party libraries should always supply an 'overrideId'. 
    const Str? overrideId   := null
    
    ** Marks the override as optional; no Err is thrown if the service is not found. 
    ** 
    ** This allows you to override services that may or may not be defined in the registry.
    ** (e.g. overriding services from optional 3rd party libraries.)
    const Bool optional := false
}