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Avoid using $q unless necessary. Most async methods already return a promise
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/** | |
* This service showcases when to use $q to return promises and when it's not necessary' | |
*/ | |
angular.module('sample').factory('sampleService', ['$q', '$http', function ($q, $http) { | |
var service = {}; | |
// Use constants, don't do this | |
var url = 'https://api.github.com/users/pablotdl/repos'; | |
/** | |
* This service uses $q to wrap an $http call to the Github API | |
*/ | |
service.getRepos = function () { | |
var deferred = $q.defer(); | |
$http.get(url) | |
.success(function (data) { | |
// Assuming $http will deserialize the JSON response automagically | |
deferred.resolve(data); | |
}) | |
.error(function (error) { | |
deferred.reject(error) | |
}); | |
return deferred.promise; | |
} | |
/** | |
* This service returns the promise returned by $http directly | |
*/ | |
service.getReposProper = function () { | |
// Unlike then, success callbacks cannot be chained | |
// Then callbacks will be executed one after the other. | |
return $http.get(url) | |
//The then callback will receive a response... we are only interested in the data property | |
.then(_.property('data')); | |
} | |
/** | |
* In this example, we want to return the URL we are using, but want to do so maintaining | |
* the promise pattern | |
*/ | |
service.getUrl = function () { | |
var deferred = $q.defer(); | |
deferred.resolve(url); | |
return deferred.promise; | |
} | |
/** | |
* And this is how it should be done | |
*/ | |
service.getUrlProper = function () { | |
return $q.when(url); | |
} | |
return service; | |
}]); |
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