The $provide service has a number of methods for registering components
with the $injector. Many of these functions are also exposed on
angular.Module.
An Angular service is a singleton object created by a service factory. These service
factories are functions which, in turn, are created by a service provider.
The service providers are constructor functions. When instantiated they must contain a
property called $get, which holds the service factory function.
When you request a service, the $injector is responsible for finding the
correct service provider, instantiating it and then calling its $get service factory
function to get the instance of the service.
Often services have no configuration options and there is no need to add methods to the service
provider. The provider will be no more than a constructor function with a $get property. For
these cases the $provide service has additional helper methods to register
services without specifying a provider.
fn,
that will be wrapped in a service provider object, whose $get property will contain the
given factory function.class
that will be wrapped in a service provider object, whose $get property will instantiate
a new object using the given constructor function.See the individual methods for more information and examples.
provider(name, provider);
Register a provider function with the $injector. Provider functions are constructor functions, whose instances are responsible for "providing" a factory for a service.
Service provider names start with the name of the service they provide followed by Provider.
For example, the $log service has a provider called
$logProvider.
Service provider objects can have additional methods which allow configuration of the provider
and its service. Importantly, you can configure what kind of service is created by the $get
method, or how that service will act. For example, the $logProvider has a
method debugEnabled
which lets you specify whether the $log service will log debug messages to the
console or not.
| Param | Type | Details |
|---|---|---|
| name | string |
The name of the instance. NOTE: the provider will be available under |
| provider | Objectfunction() |
If the provider is:
|
| Object | registered provider instance |
factory(name, $getFn);
Register a service factory, which will be called to return the service instance.
This is short for registering a service where its provider consists of only a $get property,
which is the given service factory function.
You should use $provide.factory(getFn) if you do not need to
configure your service in a provider.
| Param | Type | Details |
|---|---|---|
| name | string |
The name of the instance. |
| $getFn | function()Array.<(string|function())> |
The injectable $getFn for the instance creation.
Internally this is a short hand for |
| Object | registered provider instance |
service(name, constructor);
Register a service constructor, which will be invoked with new to create the service
instance.
This is short for registering a service where its provider's $get property is a factory
function that returns an instance instantiated by the injector from the service constructor
function.
Internally it looks a bit like this:
{
$get: function() {
return $injector.instantiate(constructor);
}
}
You should use $provide.service(class) if you define your service as a type/class.
| Param | Type | Details |
|---|---|---|
| name | string |
The name of the instance. |
| constructor | function()Array.<(string|function())> |
An injectable class (constructor function) that will be instantiated. |
| Object | registered provider instance |
value(name, value);
Register a value service with the $injector, such as a string, a
number, an array, an object or a function. This is short for registering a service where its
provider's $get property is a factory function that takes no arguments and returns the value
service.
Value services are similar to constant services, except that they cannot be injected into a
module configuration function (see angular.Module) but they can be overridden by
an Angular
decorator.
| Param | Type | Details |
|---|---|---|
| name | string |
The name of the instance. |
| value | * |
The value. |
| Object | registered provider instance |
constant(name, value);
Register a constant service, such as a string, a number, an array, an object or a function,
with the $injector. Unlike value it can be
injected into a module configuration function (see angular.Module) and it cannot
be overridden by an Angular decorator.
| Param | Type | Details |
|---|---|---|
| name | string |
The name of the constant. |
| value | * |
The constant value. |
| Object | registered instance |
decorator(name, decorator);
Register a service decorator with the $injector. A service decorator intercepts the creation of a service, allowing it to override or modify the behavior of the service. The object returned by the decorator may be the original service, or a new service object which replaces or wraps and delegates to the original service.
| Param | Type | Details |
|---|---|---|
| name | string |
The name of the service to decorate. |
| decorator | function()Array.<(string|function())> |
This function will be invoked when the service needs to be instantiated and should return the decorated service instance. The function is called using the injector.invoke method and is therefore fully injectable. Local injection arguments:
|