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diff --git a/docs/content/api/angular.service.ngdoc b/docs/content/api/angular.service.ngdoc index 9a191921..0d3406e5 100644 --- a/docs/content/api/angular.service.ngdoc +++ b/docs/content/api/angular.service.ngdoc @@ -1,32 +1,175 @@ @workInProgress @ngdoc overview @name angular.service + @description +# Overview +Services are substituable objects, which are wired together using dependency injection (DI). +Each service could have dependencies (other services), which are passed in constructor. +Because JS is dynamicaly typed language, dependency injection can not use static types +to identify these dependencies, so each service must explicitely define its dependencies. +This is done by `$inject` property. + + +# Built-in services +angular provides a set of services for common operations. These services can be overriden by custom +services if needed. + +Like other core angular variables and identifiers, the built-in services always start with `$`. + + * {@link angular.service.$browser $browser} + * {@link angular.service.$window $window} + * {@link angular.service.$document $document} + * {@link angular.service.$location $location} + * {@link angular.service.$log $log} + * {@link angular.service.$exceptionHandler $exceptionHandler} + * {@link angular.service.$hover $hover} + * {@link angular.service.$invalidWidgets $invalidWidgets} + * {@link angular.service.$route $route} + * {@link angular.service.$xhr $xhr} + * {@link angular.service.$xhr.error $xhr.error} + * {@link angular.service.$xhr.bulk $xhr.bulk} + * {@link angular.service.$xhr.cache $xhr.cache} + * {@link angular.service.$resource $resource} + * {@link angular.service.$cookies $cookies} + * {@link angular.service.$cookieStore $cookieStore} + +# Writing your own custom services +angular provides only set of basic services, so for any nontrivial application it will be necessary +to write one or more custom services. To do so, a factory function that creates a services needs to +be registered with angular's dependency injector. This factory function must return an object - the +service (it is not called with the `new` operator). + +**angular.service** accepts three parameters: + + - `{string} name` - Name of the service. + - `{function()} factory` - Factory function (called just once by DI). + - `{Object} config` - Configuration object with following properties: + - `$inject` - {Array.<string>} - Array of service ids that this service depends on. These + services will be passed as arguments into the factory function in the same order as specified + in the `$inject` array. Defaults to `[]`. + - `$eager` - {boolean} - If true, the service factory will be called and thus, the service will + be instantiated when angular boots. If false, service will be lazily instantiated when it is + first requested during instantiation of a dependant. Defaults to `false`. + +The `this` of the factory function is bound to the root scope of the angular application. + +angular enables services to participate in dependency injection (DI) by registering themselves with +angular's DI system (injector) under a `name` (id) as well as by declaring dependencies which need +to be provided for the factory function of the registered service. The ability to swap dependencies +for mocks/stubs/dummies in tests allows for services to be highly testable. + +Here is an example of very simple service. This service requires $window service (it's +passed as a parameter to factory function) and it's just a function. + +This service simple stores all notifications and after third one, it displays all of them by +window alert. +<pre> + angular.service('notify', function(win) { + var msgs = []; + return function(msg) { + msgs.push(msg); + if (msgs.length == 3) { + win.alert(msgs.join("\n")); + msgs = []; + } + }; + }, {$inject: ['$window']}); +</pre> + +And here is a unit test for this service. We use Jasmine spy (mock) instead of real browser's alert. +<pre> +var mock, notify; + +beforeEach(function() { + mock = {alert: jasmine.createSpy()}; + notify = angular.service('notify')(mock); +}); + +it('should not alert first two notifications', function() { + notify('one'); + notify('two'); + expect(mock.alert).not.toHaveBeenCalled(); +}); + +it('should alert all after third notification', function() { + notify('one'); + notify('two'); + notify('three'); + expect(mock.alert).toHaveBeenCalledWith("one\ntwo\nthree"); +}); + +it('should clear messages after alert', function() { + notify('one'); + notify('two'); + notify('third'); + notify('more'); + notify('two'); + notify('third'); + expect(mock.alert.callCount).toEqual(2); + expect(mock.alert.mostRecentCall.args).toEqual(["more\ntwo\nthird"]); +}); +</pre> + +# Injecting services into controllers +Using services as dependencies for controllers is very similar to using them as dependencies for +another service. + +JavaScript is dynamic language, so DI is not able to figure out which services to inject by +static types (like in static typed languages). Therefore you must specify the service name +by the `$inject` property - it's an array that contains strings with names of services to be +injected. The name must match the id that service has been registered as with angular. +The order of the services in the array matters, because this order will be used when calling +the factory function with injected parameters. The names of parameters in factory function +don't matter, but by convention they match the service ids. +<pre> +function myController($loc, $log) { + this.firstMethod = function() { + // use $location service + $loc.setHash(); + }; + this.secondMethod = function() { + // use $log service + $log.info('...'); + }; +} +// which services to inject ? +myController.$inject = ['$location', '$log']; +</pre> + +@example +<doc:example> + <doc:source> + <script type="text/javascript"> + angular.service('notify', function(win) { + var msgs = []; + return function(msg) { + msgs.push(msg); + if (msgs.length == 3) { + win.alert(msgs.join("\n")); + msgs = []; + } + }; + }, {$inject: ['$window']}); + + function myController(notifyService) { + this.callNotify = function(msg) { + notifyService(msg); + }; + } + myController.$inject = ['notify']; + </script> -The services API provides objects for carrying out common web app tasks. Service objects are -managed by angular's {@link guide/dev_guide.di dependency injection system}. - - -* {@link angular.service.$browser $browser } - Provides an instance of a browser object -* {@link angular.service.$cookieStore $cookieStore } - Provides key / value storage backed by -session cookies -* {@link angular.service.$cookies $cookies } - Provides read / write access to browser cookies -* {@link angular.service.$defer $defer } - Defers function execution and try / catch block -* {@link angular.service.$document $document } - Provides reference to `window.document` element -* {@link angular.service.$exceptionHandler $exceptionHandler } - Receives uncaught angular -exceptions -* {@link angular.service.$hover $hover } - -* {@link angular.service.$invalidWidgets $invalidWidgets } - Holds references to invalid widgets -* {@link angular.service.$location $location } - Parses the browser location URL -* {@link angular.service.$log $log } - Provides logging service -* {@link angular.service.$resource $resource } - Creates objects for interacting with RESTful -server-side data sources -* {@link angular.service.$route $route } - Provides deep-linking services -* {@link angular.service.$updateView $updateView } - Queues view updates -* {@link angular.service.$window $window } - References the browsers `window` object -* {@link angular.service.$xhr $xhr} - Generates an XHR request. - - -For information on how angular services work and how to write your own services, see {@link -guide/dev_guide.services Angular Services} in the angular Developer Guide. + <div ng:controller="myController"> + <p>Let's try this simple notify service, injected into the controller...</p> + <input ng:init="message='test'" type="text" name="message" /> + <button ng:click="callNotify(message);">NOTIFY</button> + </div> + </doc:source> + <doc:scenario> + it('should test service', function(){ + expect(element(':input[name=message]').val()).toEqual('test'); + }); + </doc:scenario> +</doc:example> |