angular.js/src/auto/injector.js
Pete Bacon Darwin 770353df19 docs($provide): improve docs and examples further
Improve the "tracking" service example by adding a configuration option.
Get better formatting of the generated code samples using <pre> tags.
Move the detailed explanations into each function's documentation block.
Improve the overview and list the constituent functions by significance.

Closes #4302
2013-10-10 18:22:52 +01:00

757 lines
26 KiB
JavaScript

'use strict';
/**
* @ngdoc function
* @name angular.injector
* @function
*
* @description
* Creates an injector function that can be used for retrieving services as well as for
* dependency injection (see {@link guide/di dependency injection}).
*
* @param {Array.<string|Function>} modules A list of module functions or their aliases. See
* {@link angular.module}. The `ng` module must be explicitly added.
* @returns {function()} Injector function. See {@link AUTO.$injector $injector}.
*
* @example
* Typical usage
* <pre>
* // create an injector
* var $injector = angular.injector(['ng']);
*
* // use the injector to kick off your application
* // use the type inference to auto inject arguments, or use implicit injection
* $injector.invoke(function($rootScope, $compile, $document){
* $compile($document)($rootScope);
* $rootScope.$digest();
* });
* </pre>
*/
/**
* @ngdoc overview
* @name AUTO
* @description
*
* Implicit module which gets automatically added to each {@link AUTO.$injector $injector}.
*/
var FN_ARGS = /^function\s*[^\(]*\(\s*([^\)]*)\)/m;
var FN_ARG_SPLIT = /,/;
var FN_ARG = /^\s*(_?)(\S+?)\1\s*$/;
var STRIP_COMMENTS = /((\/\/.*$)|(\/\*[\s\S]*?\*\/))/mg;
function annotate(fn) {
var $inject,
fnText,
argDecl,
last;
if (typeof fn == 'function') {
if (!($inject = fn.$inject)) {
$inject = [];
fnText = fn.toString().replace(STRIP_COMMENTS, '');
argDecl = fnText.match(FN_ARGS);
forEach(argDecl[1].split(FN_ARG_SPLIT), function(arg){
arg.replace(FN_ARG, function(all, underscore, name){
$inject.push(name);
});
});
fn.$inject = $inject;
}
} else if (isArray(fn)) {
last = fn.length - 1;
assertArgFn(fn[last], 'fn');
$inject = fn.slice(0, last);
} else {
assertArgFn(fn, 'fn', true);
}
return $inject;
}
///////////////////////////////////////
/**
* @ngdoc object
* @name AUTO.$injector
* @function
*
* @description
*
* `$injector` is used to retrieve object instances as defined by
* {@link AUTO.$provide provider}, instantiate types, invoke methods,
* and load modules.
*
* The following always holds true:
*
* <pre>
* var $injector = angular.injector();
* expect($injector.get('$injector')).toBe($injector);
* expect($injector.invoke(function($injector){
* return $injector;
* }).toBe($injector);
* </pre>
*
* # Injection Function Annotation
*
* JavaScript does not have annotations, and annotations are needed for dependency injection. The
* following are all valid ways of annotating function with injection arguments and are equivalent.
*
* <pre>
* // inferred (only works if code not minified/obfuscated)
* $injector.invoke(function(serviceA){});
*
* // annotated
* function explicit(serviceA) {};
* explicit.$inject = ['serviceA'];
* $injector.invoke(explicit);
*
* // inline
* $injector.invoke(['serviceA', function(serviceA){}]);
* </pre>
*
* ## Inference
*
* In JavaScript calling `toString()` on a function returns the function definition. The definition can then be
* parsed and the function arguments can be extracted. *NOTE:* This does not work with minification, and obfuscation
* tools since these tools change the argument names.
*
* ## `$inject` Annotation
* By adding a `$inject` property onto a function the injection parameters can be specified.
*
* ## Inline
* As an array of injection names, where the last item in the array is the function to call.
*/
/**
* @ngdoc method
* @name AUTO.$injector#get
* @methodOf AUTO.$injector
*
* @description
* Return an instance of the service.
*
* @param {string} name The name of the instance to retrieve.
* @return {*} The instance.
*/
/**
* @ngdoc method
* @name AUTO.$injector#invoke
* @methodOf AUTO.$injector
*
* @description
* Invoke the method and supply the method arguments from the `$injector`.
*
* @param {!function} fn The function to invoke. The function arguments come form the function annotation.
* @param {Object=} self The `this` for the invoked method.
* @param {Object=} locals Optional object. If preset then any argument names are read from this object first, before
* the `$injector` is consulted.
* @returns {*} the value returned by the invoked `fn` function.
*/
/**
* @ngdoc method
* @name AUTO.$injector#instantiate
* @methodOf AUTO.$injector
* @description
* Create a new instance of JS type. The method takes a constructor function invokes the new operator and supplies
* all of the arguments to the constructor function as specified by the constructor annotation.
*
* @param {function} Type Annotated constructor function.
* @param {Object=} locals Optional object. If preset then any argument names are read from this object first, before
* the `$injector` is consulted.
* @returns {Object} new instance of `Type`.
*/
/**
* @ngdoc method
* @name AUTO.$injector#annotate
* @methodOf AUTO.$injector
*
* @description
* Returns an array of service names which the function is requesting for injection. This API is used by the injector
* to determine which services need to be injected into the function when the function is invoked. There are three
* ways in which the function can be annotated with the needed dependencies.
*
* # Argument names
*
* The simplest form is to extract the dependencies from the arguments of the function. This is done by converting
* the function into a string using `toString()` method and extracting the argument names.
* <pre>
* // Given
* function MyController($scope, $route) {
* // ...
* }
*
* // Then
* expect(injector.annotate(MyController)).toEqual(['$scope', '$route']);
* </pre>
*
* This method does not work with code minfication / obfuscation. For this reason the following annotation strategies
* are supported.
*
* # The `$inject` property
*
* If a function has an `$inject` property and its value is an array of strings, then the strings represent names of
* services to be injected into the function.
* <pre>
* // Given
* var MyController = function(obfuscatedScope, obfuscatedRoute) {
* // ...
* }
* // Define function dependencies
* MyController.$inject = ['$scope', '$route'];
*
* // Then
* expect(injector.annotate(MyController)).toEqual(['$scope', '$route']);
* </pre>
*
* # The array notation
*
* It is often desirable to inline Injected functions and that's when setting the `$inject` property is very
* inconvenient. In these situations using the array notation to specify the dependencies in a way that survives
* minification is a better choice:
*
* <pre>
* // We wish to write this (not minification / obfuscation safe)
* injector.invoke(function($compile, $rootScope) {
* // ...
* });
*
* // We are forced to write break inlining
* var tmpFn = function(obfuscatedCompile, obfuscatedRootScope) {
* // ...
* };
* tmpFn.$inject = ['$compile', '$rootScope'];
* injector.invoke(tmpFn);
*
* // To better support inline function the inline annotation is supported
* injector.invoke(['$compile', '$rootScope', function(obfCompile, obfRootScope) {
* // ...
* }]);
*
* // Therefore
* expect(injector.annotate(
* ['$compile', '$rootScope', function(obfus_$compile, obfus_$rootScope) {}])
* ).toEqual(['$compile', '$rootScope']);
* </pre>
*
* @param {function|Array.<string|Function>} fn Function for which dependent service names need to be retrieved as described
* above.
*
* @returns {Array.<string>} The names of the services which the function requires.
*/
/**
* @ngdoc object
* @name AUTO.$provide
*
* @description
*
* The {@link AUTO.$provide $provide} service has a number of methods for registering components with
* the {@link AUTO.$injector $injector}. Many of these functions are also exposed on {@link angular.Module}.
*
* An Angular **service** is a singleton object created by a **service factory**. These **service
* factories** are functions which, in turn, are created by a **service provider**.
* The **service providers** are constructor functions. When instantiated they must contain a property
* called `$get`, which holds the **service factory** function.
*
* When you request a service, the {@link AUTO.$injector $injector} is responsible for finding the
* correct **service provider**, instantiating it and then calling its `$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 `$get` property. For
* these cases the {@link AUTO.$provide $provide} service has additional helper methods to register
* services without specifying a provider.
*
* * {@link AUTO.$provide#provider provider(provider)} - registers a **service provider** with the
* {@link AUTO.$injector $injector}
* * {@link AUTO.$provide#constant constant(obj)} - registers a value/object that can be accessed by
* providers and services.
* * {@link AUTO.$provide#value value(obj)} - registers a value/object that can only be accessed by
* services, not providers.
* * {@link AUTO.$provide#factory factory(fn)} - registers a service **factory function**, `fn`, that
* will be wrapped in a **service provider** object, whose `$get` property will contain the given
* factory function.
* * {@link AUTO.$provide#service service(class)} - registers a **constructor function**, `class` that
* will be wrapped in a **service provider** object, whose `$get` property will instantiate a new
* object using the given constructor function.
*
* See the individual methods for more information and examples.
*/
/**
* @ngdoc method
* @name AUTO.$provide#provider
* @methodOf AUTO.$provide
* @description
*
* Register a **provider function** with the {@link AUTO.$injector $injector}. Provider functions are
* constructor functions, whose instances are responsible for "providing" a factory for a service.
*
* Service provider names start with the name of the service they provide followed by `Provider`.
* For example, the {@link ng.$log $log} service has a provider called {@link ng.$logProvider $logProvider}.
*
* Service provider objects can have additional methods which allow configuration of the provider and
* its service. Importantly, you can configure what kind of service is created by the `$get` method,
* or how that service will act. For example, the {@link ng.$logProvider $logProvider} has a method
* {@link ng.$logProvider#debugEnabled debugEnabled}
* which lets you specify whether the {@link ng.$log $log} service will log debug messages to the
* console or not.
*
* @param {string} name The name of the instance. NOTE: the provider will be available under `name + 'Provider'` key.
* @param {(Object|function())} provider If the provider is:
*
* - `Object`: then it should have a `$get` method. The `$get` method will be invoked using
* {@link AUTO.$injector#invoke $injector.invoke()} when an instance needs to be created.
* - `Constructor`: a new instance of the provider will be created using
* {@link AUTO.$injector#instantiate $injector.instantiate()}, then treated as `object`.
*
* @returns {Object} registered provider instance
* @example
*
* The following example shows how to create a simple event tracking service and register it using
* {@link AUTO.$provide#provider $provide.provider()}.
*
* <pre>
* // Define the eventTracker provider
* function EventTrackerProvider() {
* var trackingUrl = '/track';
*
* // A provider method for configuring where the tracked events should been saved
* this.setTrackingUrl = function(url) {
* trackingUrl = url;
* };
*
* // The service factory function
* this.$get = ['$http', function($http) {
* var trackedEvents = {};
* return {
* // Call this to track an event
* event: function(event) {
* var count = trackedEvents[event] || 0;
* count += 1;
* trackedEvents[event] = count;
* return count;
* },
* // Call this to save the tracked events to the trackingUrl
* save: function() {
* $http.post(trackingUrl, trackedEvents);
* }
* };
* }];
* }
*
* describe('eventTracker', function() {
* var postSpy;
*
* beforeEach(module(function($provide) {
* // Register the eventTracker provider
* $provide.provider('eventTracker', EventTrackerProvider);
* }));
*
* beforeEach(module(function(eventTrackerProvider) {
* // Configure eventTracker provider
* eventTrackerProvider.setTrackingUrl('/custom-track');
* }));
*
* it('tracks events', inject(function(eventTracker) {
* expect(eventTracker.event('login')).toEqual(1);
* expect(eventTracker.event('login')).toEqual(2);
* }));
*
* it('saves to the tracking url', inject(function(eventTracker, $http) {
* postSpy = spyOn($http, 'post');
* eventTracker.event('login');
* eventTracker.save();
* expect(postSpy).toHaveBeenCalled();
* expect(postSpy.mostRecentCall.args[0]).not.toEqual('/track');
* expect(postSpy.mostRecentCall.args[0]).toEqual('/custom-track');
* expect(postSpy.mostRecentCall.args[1]).toEqual({ 'login': 1 });
* }));
* });
* </pre>
*/
/**
* @ngdoc method
* @name AUTO.$provide#factory
* @methodOf AUTO.$provide
* @description
*
* 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 `$get` property,
* which is the given service factory function.
* You should use {@link AUTO.$provide#factory $provide.factor(getFn)} if you do not need to configure
* your service in a provider.
*
* @param {string} name The name of the instance.
* @param {function()} $getFn The $getFn for the instance creation. Internally this is a short hand for
* `$provide.provider(name, {$get: $getFn})`.
* @returns {Object} registered provider instance
*
* @example
* Here is an example of registering a service
* <pre>
* $provide.factory('ping', ['$http', function($http) {
* return function ping() {
* return $http.send('/ping');
* };
* }]);
* </pre>
* You would then inject and use this service like this:
* <pre>
* someModule.controller('Ctrl', ['ping', function(ping) {
* ping();
* }]);
* </pre>
*/
/**
* @ngdoc method
* @name AUTO.$provide#service
* @methodOf AUTO.$provide
* @description
*
* Register a **service constructor**, which will be invoked with `new` to create the service instance.
* This is short for registering a service where its provider's `$get` property is the service
* constructor function that will be used to instantiate the service instance.
*
* You should use {@link AUTO.$provide#service $provide.service(class)} if you define your service
* as a type/class. This is common when using {@link http://coffeescript.org CoffeeScript}.
*
* @param {string} name The name of the instance.
* @param {Function} constructor A class (constructor function) that will be instantiated.
* @returns {Object} registered provider instance
*
* @example
* Here is an example of registering a service using {@link AUTO.$provide#service $provide.service(class)}
* that is defined as a CoffeeScript class.
* <pre>
* class Ping
* constructor: (@$http)->
* send: ()=>
* @$http.get('/ping')
*
* $provide.service('ping', ['$http', Ping])
* </pre>
* You would then inject and use this service like this:
* <pre>
* someModule.controller 'Ctrl', ['ping', (ping)->
* ping.send()
* ]
* </pre>
*/
/**
* @ngdoc method
* @name AUTO.$provide#value
* @methodOf AUTO.$provide
* @description
*
* Register a **value service** with the {@link AUTO.$injector $injector}, such as a string, a number,
* an array, an object or a function. This is short for registering a service where its provider's
* `$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 {@link angular.Module#config}) but they can be overridden by an Angular
* {@link AUTO.$provide#decorator decorator}.
*
* @param {string} name The name of the instance.
* @param {*} value The value.
* @returns {Object} registered provider instance
*
* @example
* Here are some examples of creating value services.
* <pre>
* $provide.constant('ADMIN_USER', 'admin');
*
* $provide.constant('RoleLookup', { admin: 0, writer: 1, reader: 2 });
*
* $provide.constant('halfOf', function(value) {
* return value / 2;
* });
* </pre>
*/
/**
* @ngdoc method
* @name AUTO.$provide#constant
* @methodOf AUTO.$provide
* @description
*
* Register a **constant service**, such as a string, a number, an array, an object or a function, with
* the {@link AUTO.$injector $injector}. Unlike {@link AUTO.$provide#value value} it can be injected
* into a module configuration function (see {@link angular.Module#config}) and it cannot be
* overridden by an Angular {@link AUTO.$provide#decorator decorator}.
*
* @param {string} name The name of the constant.
* @param {*} value The constant value.
* @returns {Object} registered instance
*
* @example
* Here a some examples of creating constants:
* <pre>
* $provide.constant('SHARD_HEIGHT', 306);
*
* $provide.constant('MY_COLOURS', ['red', 'blue', 'grey']);
*
* $provide.constant('double', function(value) {
* return value * 2;
* });
* </pre>
*/
/**
* @ngdoc method
* @name AUTO.$provide#decorator
* @methodOf AUTO.$provide
* @description
*
* Register a **service decorator** with the {@link AUTO.$injector $injector}. A service decorator
* intercepts the creation of a service, allowing it to override or modify the behaviour of the
* service. The object returned by the decorator may be the original service, or a new service object
* which replaces or wraps and delegates to the original service.
*
* @param {string} name The name of the service to decorate.
* @param {function()} decorator This function will be invoked when the service needs to be
* instantiated and should return the decorated service instance. The function is called using
* the {@link AUTO.$injector#invoke injector.invoke} method and is therefore fully injectable.
* Local injection arguments:
*
* * `$delegate` - The original service instance, which can be monkey patched, configured,
* decorated or delegated to.
*
* @example
* Here we decorate the {@link ng.$log $log} service to convert warnings to errors by intercepting
* calls to {@link ng.$log#error $log.warn()}.
* <pre>
* $provider.decorator('$log', ['$delegate', function($delegate) {
* $delegate.warn = $delegate.error;
* return $delegate;
* }]);
* </pre>
*/
function createInjector(modulesToLoad) {
var INSTANTIATING = {},
providerSuffix = 'Provider',
path = [],
loadedModules = new HashMap(),
providerCache = {
$provide: {
provider: supportObject(provider),
factory: supportObject(factory),
service: supportObject(service),
value: supportObject(value),
constant: supportObject(constant),
decorator: decorator
}
},
providerInjector = createInternalInjector(providerCache, function() {
throw Error("Unknown provider: " + path.join(' <- '));
}),
instanceCache = {},
instanceInjector = (instanceCache.$injector =
createInternalInjector(instanceCache, function(servicename) {
var provider = providerInjector.get(servicename + providerSuffix);
return instanceInjector.invoke(provider.$get, provider);
}));
forEach(loadModules(modulesToLoad), function(fn) { instanceInjector.invoke(fn || noop); });
return instanceInjector;
////////////////////////////////////
// $provider
////////////////////////////////////
function supportObject(delegate) {
return function(key, value) {
if (isObject(key)) {
forEach(key, reverseParams(delegate));
} else {
return delegate(key, value);
}
}
}
function provider(name, provider_) {
if (isFunction(provider_) || isArray(provider_)) {
provider_ = providerInjector.instantiate(provider_);
}
if (!provider_.$get) {
throw Error('Provider ' + name + ' must define $get factory method.');
}
return providerCache[name + providerSuffix] = provider_;
}
function factory(name, factoryFn) { return provider(name, { $get: factoryFn }); }
function service(name, constructor) {
return factory(name, ['$injector', function($injector) {
return $injector.instantiate(constructor);
}]);
}
function value(name, value) { return factory(name, valueFn(value)); }
function constant(name, value) {
providerCache[name] = value;
instanceCache[name] = value;
}
function decorator(serviceName, decorFn) {
var origProvider = providerInjector.get(serviceName + providerSuffix),
orig$get = origProvider.$get;
origProvider.$get = function() {
var origInstance = instanceInjector.invoke(orig$get, origProvider);
return instanceInjector.invoke(decorFn, null, {$delegate: origInstance});
};
}
////////////////////////////////////
// Module Loading
////////////////////////////////////
function loadModules(modulesToLoad){
var runBlocks = [];
forEach(modulesToLoad, function(module) {
if (loadedModules.get(module)) return;
loadedModules.put(module, true);
if (isString(module)) {
var moduleFn = angularModule(module);
runBlocks = runBlocks.concat(loadModules(moduleFn.requires)).concat(moduleFn._runBlocks);
try {
for(var invokeQueue = moduleFn._invokeQueue, i = 0, ii = invokeQueue.length; i < ii; i++) {
var invokeArgs = invokeQueue[i],
provider = invokeArgs[0] == '$injector'
? providerInjector
: providerInjector.get(invokeArgs[0]);
provider[invokeArgs[1]].apply(provider, invokeArgs[2]);
}
} catch (e) {
if (e.message) e.message += ' from ' + module;
throw e;
}
} else if (isFunction(module)) {
try {
runBlocks.push(providerInjector.invoke(module));
} catch (e) {
if (e.message) e.message += ' from ' + module;
throw e;
}
} else if (isArray(module)) {
try {
runBlocks.push(providerInjector.invoke(module));
} catch (e) {
if (e.message) e.message += ' from ' + String(module[module.length - 1]);
throw e;
}
} else {
assertArgFn(module, 'module');
}
});
return runBlocks;
}
////////////////////////////////////
// internal Injector
////////////////////////////////////
function createInternalInjector(cache, factory) {
function getService(serviceName) {
if (typeof serviceName !== 'string') {
throw Error('Service name expected');
}
if (cache.hasOwnProperty(serviceName)) {
if (cache[serviceName] === INSTANTIATING) {
throw Error('Circular dependency: ' + path.join(' <- '));
}
return cache[serviceName];
} else {
try {
path.unshift(serviceName);
cache[serviceName] = INSTANTIATING;
return cache[serviceName] = factory(serviceName);
} finally {
path.shift();
}
}
}
function invoke(fn, self, locals){
var args = [],
$inject = annotate(fn),
length, i,
key;
for(i = 0, length = $inject.length; i < length; i++) {
key = $inject[i];
args.push(
locals && locals.hasOwnProperty(key)
? locals[key]
: getService(key)
);
}
if (!fn.$inject) {
// this means that we must be an array.
fn = fn[length];
}
// Performance optimization: http://jsperf.com/apply-vs-call-vs-invoke
switch (self ? -1 : args.length) {
case 0: return fn();
case 1: return fn(args[0]);
case 2: return fn(args[0], args[1]);
case 3: return fn(args[0], args[1], args[2]);
case 4: return fn(args[0], args[1], args[2], args[3]);
case 5: return fn(args[0], args[1], args[2], args[3], args[4]);
case 6: return fn(args[0], args[1], args[2], args[3], args[4], args[5]);
case 7: return fn(args[0], args[1], args[2], args[3], args[4], args[5], args[6]);
case 8: return fn(args[0], args[1], args[2], args[3], args[4], args[5], args[6], args[7]);
case 9: return fn(args[0], args[1], args[2], args[3], args[4], args[5], args[6], args[7], args[8]);
case 10: return fn(args[0], args[1], args[2], args[3], args[4], args[5], args[6], args[7], args[8], args[9]);
default: return fn.apply(self, args);
}
}
function instantiate(Type, locals) {
var Constructor = function() {},
instance, returnedValue;
// Check if Type is annotated and use just the given function at n-1 as parameter
// e.g. someModule.factory('greeter', ['$window', function(renamed$window) {}]);
Constructor.prototype = (isArray(Type) ? Type[Type.length - 1] : Type).prototype;
instance = new Constructor();
returnedValue = invoke(Type, instance, locals);
return isObject(returnedValue) ? returnedValue : instance;
}
return {
invoke: invoke,
instantiate: instantiate,
get: getService,
annotate: annotate
};
}
}