How to use data from http request in angularjs controller? - javascript

I'm a code newbie and trying to learn angularjs. My project is simple: get JSON data from an API and display it on a web page. I found functions to make the http request and then use the data:
app.factory('myService', function($http) {
var myService = {
async: function() {
var promise = $http.get('<URL to api>').then(function(response) {
console.log(response);
return response.data;
});
return promise;
}
};
return myService;
});
app.controller('getRealTimeBusDataCtrl', function(myService, $scope) {
myService.async().then(function(d) {
$scope.data = d;
});
});
I can then access and display the whole JSON data chunk or parts of it.
What I'd like to do is set multiple $scope variables instead of just one, but as soon as I try that, the code breaks.
What I'm trying to do:
if (d.ResponseData.Buses[1].JourneyDirection = 1) {
$scope.timeToSollentuna = d.ResponseData.Buses[1].DisplayTime;
else if (d.ResponseData.Buses[1].JourneyDirection = 2) {
$scope.timeToVallingby = d.ResponseData.Buses[1].DisplayTime;
} else if (d.ResponseData.Buses[2].JourneyDirection = 1) {
$scope.timeToSollentuna = d.ResponseData.Buses[2].DisplayTime;
} else {
$scope.timeToVallingby = d.ResponseData.Buses[2].DisplayTime;
}
}
I'm guessing the problem is how the function is set up: that it somehow limits the number of variables I can set or the number of things I can "do" after .then, but I haven't been able to figure out another way to do it.
Sorry if the answer to this question is SO obvious, but I've really tried to find it and failed.
Best regards,

The way that service is written is unnecessarily verbose. Instead, I would rewrite it like this (especially if you're starting out and learning the basics--it's good to learn good habits when starting).
app.factory('myService', ["$http", function($http){
return {
getData: function() {
return $http.get('path/to/api');
}
};
}]);
app.controller('MainCtrl', ["$scope", "myService", function($scope, myService) {
//declare your data model first
$scope.busData = undefined;
//use the service to get data
myService.getData().then(function(response) {
//success... got a response
//this is where you can apply your data
$scope.busData = response.data;
//call a function to apply if you'd like
applyBusData(response.data);
}).catch(function(response) {
//error has occurred
});
function applyBusData(data) {
if(data.Buses[1].JourneyDirection === 1) {
//etcc... etc...
} else {
//etc.. etc...
}
}
}]);

Related

Configuring which entities to alert about in JHipster

I've a jHipster project with the 4.5.1 version (Angular 1) and it does a really nice job. However, I'm already modifying the generated frontend code, which is CRUD focused for all entities, and want to unify many of them.
That said, I would like to be able to choose which entities to alert about using UI-Bootstrap. Now, when I save EntityA which manages EntityB in the same view, I get two alerts for each of the entities. I just want to get the message about the first one.
Is there any way to do it? Or just better, to disable the automatic entity messaging and doing it by hand in the controllers?
The interpectors for the angular http requests are kept in app/blocks/interceptor. There, there's a file called notification.interceptor.js and there's no filter for the entities being displayed, so we need to configure it in some way:
(function() {
'use strict';
angular
.module('myApp')
.factory('notificationInterceptor', notificationInterceptor);
notificationInterceptor.$inject = ['$q', 'AlertService'];
function notificationInterceptor ($q, AlertService) {
var service = {
response: response
};
return service;
function response (response) {
var headers = Object.keys(response.headers()).filter(function (header) {
return header.indexOf('app-alert', header.length - 'app-alert'.length) !== -1 || header.indexOf('app-params', header.length - 'app-params'.length) !== -1;
}).sort();
var alertKey = response.headers(headers[0]);
if (angular.isString(alertKey) && alertKey.indexOf('myEntityToBeDisplayed') !== -1) {
AlertService.success(alertKey, { param : response.headers(headers[1])});
}
return response;
}
}
})();
Then, if we also want to show alerts or log the error responses from the server, the errorhandler.interceptor.js intercepts each of the error responses happening. Tuning it a bit, there's the chance to show alerts for all of them:
(function() {
'use strict';
angular
.module('myApp')
.factory('errorHandlerInterceptor', errorHandlerInterceptor);
errorHandlerInterceptor.$inject = ['$q', '$rootScope'];
function errorHandlerInterceptor ($q, $rootScope) {
var service = {
responseError: responseError
};
return service;
function responseError (response) {
if (!(response.status === 401)) {
$rootScope.$emit('myApp.httpError', response);
}
return $q.reject(response);
}
}
})();
See also:
AngularJS: Catch all response status 500

manual bootstrap angular with http calls

I have a WebAPI service that returns dynamic configuration data. Before my angular app loads I would like to call that service and load the config data into angular. JSFiddle of my attempt at doing that. My question is, after seeing the string test in the console I am seeing nothing else written into the console. How do I get test 2 and wierd wierd to appear into the console
var app = angular.module('app', [])
app.provider("ConfigService", function () {
var self = this;
self.Settings = {};
self.config = function (data) {
console.log(data);
};
this.$get =
function($http) {
return self;
};
});
angular.element(document).ready(function($http) {
console.log('test')
angular.module('app').config([
'ConfigServiceProvider',
function(configService) {
console.log('test 2')
$http.get('http://www.google.com').then(function(result) {
console.log('wierd wierd')
configService.config(result);
angular.bootstrap(document, ['app']);
})
}
]);
});
EDIT
In response to the question, why I do not run this in app.run phase instead.
In the app.run phase the app is still initializing and sometimes it loads up prior to my configuration section being completed. I wanted 100% guarantee that my config section is loaded first before any of the app is.
You can use $http outside of your angular module with angular.injector. With $http you can request the config from your server and bootstrap your app when $http's promise resolves.
JS Fiddle
Create module
var app = angular.module("app", []);
app.provider("configService", function () {
var configService = {
config: {}
};
this.setConfig = function (config) { configService.config = config; };
this.$get = function() { return configService; };
});
Function that fetches config from server
function fetchConfig() {
var $http = angular.injector(["ng"]).get("$http");
return $http.get("http://www.google.com");
}
Function that bootstraps app
function bootstrap(config) {
app.config(["configServiceProvider", function (configServiceProvider) {
configServiceProvider.setConfig(config);
}]).run(["configService", function (configService) {
//Not necessary, just to confirm everything worked
console.log("YAY! You have a config:", configService.config);
}]);
angular.bootstrap(document, ["app"])
}
Put it all together!
fetchConfig().then(
/*sucess*/function (config) { angular.element(document).ready(function () { bootstrap(config); }); },
/*fail*/ function (err) { console.log("UH OH could not retrieve config!", err); });
EDIT: Please use #StevenWexler 's answer: https://stackoverflow.com/a/37599857/5670592. It is much more correct, uses a nifty angular feature ($inject), and will provide configuration before the beginning of the bootstrap cycle.
I have updated the application with your constraints regarding blocking execution until API call is complete.
Try this: https://jsfiddle.net/6svnemu8/3/
I moved the code to the module.run(...) block. This is where all providers are available and you can use $http and your ConfigService. I kept the bootstrap call in the document ready function, and I also added the $q service so you can block execution of the application until the API call is complete. You can verify this by looking at the order of the test outputs in the console:
angular.module('app').run([
'ConfigService', '$http', '$q',
function(configService, $http, $q) {
console.log('test 2');
var deferred = $q.defer();
$http.get('/6svnemu8/2/').then(function(result) {
deferred.resolve(result);
}, function(result){
deferred.reject(result);
});
console.log("test 3");
deferred.promise.then(function(result){
console.log('wierd wierd');
configService.config(result);
}, function(result){
console.log("call failed.");
});
}
]);
Option 1 -- if you have an MVC app
In your main razor view, use JSON.Net to serialize your Model (or a property on it) to JavaScript.
<script>
window.configuration = #(Html.Raw(JsonConvert.SerializeObject(Model)))
</script>
Then put it into an angular constant so you can inject it anywhere you need it, and it's guaranteed to be there. This is the most convenient way to do it.
angular.module('YourModule').constant('configuration', window.configuration);
Option 2 -- loading it asynchronously
This service will load the configuration and cache the promise.
angular.module('YourModule').factory('configuration', ['$http', function($http) {
var configurationLoaded;
var service = {
get: get
};
function get() {
if(configurationLoaded) return configurationLoaded;
configurationLoaded = $http.get( ... );
return configurationLoaded;
}
return service;
}]);
Then anywhere you need it, you'll have to pull out properties from it like this:
angular.module('YourModule').controller('SomeController', ['configuration', function(configuration) {
var vm = this;
configuration.get().then(function(config) {
vm.someSetting = config.someSetting;
});
}]);

Creating API factory with SwaggerJS

So I have this long standing APIService factory that creates functions to pass through the swagger functions to the UI. Here's a snippet of the factory:
'use strict';
angular.module('myApp').factory('APIService', function ($http, $window, $q, swaggerClient, $mdToast) {
var ApiDoc = {};
ApiDoc.getAllBookmarks = function () {
return $q(function (resolve, reject) {
$http.get('client/components/api/Schema.json')
.success(function (data) {
var schema = data;
_.each(schema.apis, function (b) {
b.apiDeclaration.basePath = $window.location.origin;
})
var api = swaggerClient(schema);
api = api.apiBookmarks.getAll();
resolve(api);
});
});
}
return ApiDoc;
});
And here is a snippet of it's use case in a controller:
$scope.getAllDashboards = function () {
APIService.getAllBookmarks().then(function(data){
if (data.length > 0){
$scope.dashboardsList = data;
$scope.emptyDash = false;
} else {
$scope.emptyDash = true;
}
})
}
$scope.getAllDashboards();
The inherent problem herein, is that if I have 30 API function calls in a controller, then there are 30 $http requests for schema.json that are un-needed really. Problem is that I can't figure out how to request/store that json and call on the functions with swagger the same way as they are now (or else I have to change 200+ methods in controllers, urgh). I tried this:
// var api = null;
// $http.get('client/components/api/Schema.json')
// .success(function (data) {
// var schema = data;
// _.each(schema.apis, function (b) {
// b.apiDeclaration.basePath = $window.location.origin;
// })
// api = swaggerClient(schema);
// });
But couldn't get a function after that to read it properly, or return the result of the function call in a promise like the controllers expect.
I have no other JS developers here so I need help from you all! Thanks much!
That is ugly. If you upgrade your swagger-client to something more modern, you have some options.
First off, you can cache your schema as an object, and supply it in your swaggerClient constructor using the argument spec. You'll still need to pass the URL of the target host to the client when constructing it. With that, there won't need to be any need to call anything remotely.
Next, you can see about keeping a proper swaggerClient instance around, and use it in each of your calls.

Angular - Best practice for retrieving data from a Factory method

I'm looking for some information on the best way to retrieve data from a local JSON file and handle the response. After browsing through Stack Overflow, I have some mixed thoughts as I've seen multiple ways of doing the same thing (although no explanation on why one may or may not be preferred).
Essentially, I have an Angular app that is utilising a factory to retrieve data from a JSON file; I'm then waiting for the response to resolve in my controller before using it in my html file, similar to the below:
Option 1
Factory:
comparison.factory('Info', ['$http', function($http) {
var retrievalFile = 'retrievalFile.json';
return {
retrieveInfo: function() {
return $http.get(retrievalFile);
}
}
}]);
Controller:
comparison.controller('comparisonController', ['$scope', 'Info', function($scope, Info) {
Info.retrieveInfo().then(function(response) {
$scope.info = response.data;
});
}]);
My main point of contention is figuring out when it's best to wait for the response to resolve, or if it even matters. I'm toying with the idea of having the factory return the fulfilled promise, and wait for the controller to retrieve the data also. In my view, it's best to abstract all data retrieval out of the controller and into the factory, but I'm not sure if this extends to waiting for the actual data to be returned within the factory itself. With this in mind, I'm confused about whether to opt for option 1 or option 2 and would really appreciate some feedback from more experienced/qualified developers!
Option 2
Factory:
comparison.factory('Info', ['$http', function($http) {
var retrievalFile = 'retrievalFile.json';
return {
retrieveInfo: function() {
return $http.get(retrievalFile).then(function(response) {
return response.data;
});
}
}
}]);
Controller:
comparison.controller('comparisonController', ['$scope', 'Info', function($scope, Info) {
Info.retrieveInfo().then(function(response) {
$scope.info = response;
});
}]);
Thank you for any input/suggestions in advance!
It depends on what your controller is expecting and how you set up your application. Generally, I always go with the second option. Its because I usually have global error or success handlers in all api requests and I have a shared api service. Something like below.
var app = angular.module('app', []);
app.service('ApiService', ['$http', function($http) {
var get = function(url, params) {
$http.get(url, { params: params })
.then(handleSuccess, handleError);
};
// handle your global errors here
// implementation will vary based upon how you handle error
var handleError = function(response) {
return $q.reject(response);
};
// handle your success here
// you can return response.data or response based upon what you want
var handleSuccess = function(response) {
return response.data;
};
}]);
app.service('InfoService', ['ApiService', function(ApiService) {
var retrieveInfo = function() {
return ApiService.get(retrievalFile);
/**
// or return custom object that your controller is expecting
return ApiService.get.then(function(data) {
return new Person(data);
});
**//
};
// I prefer returning public functions this way
// as I can just scroll down to the bottom of service
// to see all public functions at one place rather than
// to scroll through the large file
return { retrieveInfo: retrieveInfo };
}]);
app.controller('InfoController', ['InfoService', function(InfoService) {
InfoService.retrieveInfo().then(function(info) {
$scope.info = info;
});
}])
Or if you are using router you can resolve the data into the controller. Both ngRouter and uiRouter support resolves:
$stateProvider.state({
name: 'info',
url: '/info',
controller: 'InfoController',
template: 'some template',
resolve: {
// this injects a variable called info in your controller
// with a resolved promise that you return here
info: ['InfoService', function(InfoService) {
return InfoService.retrieveInfo();
}]
}
});
// and your controller will be like
// much cleaner right
app.controller('InfoController', ['info', function(info) {
$scope.info = info;
}]);
It's really just preference. I like to think of it in terms of API. What is the API you want to expose? Do you want your controller to receive the entire response or do you want your controller to just have the data the response wraps? If you're only ever going to use response.data then option 2 works great as you never have to deal with anything but the data you're interested in.
A good example is the app we just wrote where I work. We have two apps: a back-end API and our front-end Angular application. We created an API wrapper service in the front-end application. In the service itself we place a .catch for any of the API endpoints that have documented error codes (we used Swagger to document and define our API). In that .catch we handle those error codes and return a proper error. When our controllers/directives consume the service they get back a much stricter set of data. If an error occurs then the UI is usually safe to just display the error message sent from the wrapper service and won't have to worry about looking at error codes.
Likewise for successful responses we do much of what you're doing in option 2. In many cases we refine the data down to what is minimally useful in the actual app. In this way we keep a lot of the data churning and formatting in the service and the rest of the app has a lot less to do. For instance, if we need to create an object based on that data we'll just do that in return the object to the promise chain so that controllers aren't doing that all over the place.
I would choose option two, as it your options are really mostly the same. But let see when we add a model structure like a Person suppose.
comparison.factory('Info', ['$http', function($http) {
var retrievalFile = 'retrievalFile.json';
return {
retrieveInfo: function() {
return $http.get(retrievalFile).then(function(response) {
//we will return a Person...
var data = response.data;
return new Person(data.name, data.age, data.gender);
});
}
}
}]);
This is really simple, but if you have to map more complex data into object models (you retrieve a list of people with their own items... etc), that's when things get more complicated, you will probably want to add a service to handle the mapping between data and models. Well you have another service DataMapper(example), if you choose your first option you will have to inject DataMapper into your controller and you will have to make your request through your factory, and map the response with the injected service. And then you probably say, Should I have all this code here? ... Well probably no.
That is an hypothetical case, something that count a lot is how you feel structuring your code, won't architecture it in a way you won't understand. And at the end take a look at this: https://en.wikipedia.org/wiki/SOLID_(object-oriented_design) and research more information about this principles but focused to javascript.
Good question. A couple of points:
Controllers should be view centric versus data centric therefore you
want remove data logic from the controller and rather have it focus
on business logic.
Models (M in MVC) are a data representation of your application and
will house the data logic. In Angular case this would be a service
or factory class as you rightfully pointed out. Why is that well for
example:
2.1 AccountsController (might have multiple data models injected)
2.1.1 UserModel
2.1.2 AuthModel
2.1.3 SubscriptionModel
2.1.4 SettingsModel
There are numerous ways to approach the data model approach, but I would say your service class should be the data REST model i.e. getting, storing, caching, validating, etc. I've included a basic example, but suggest you investigate JavaScript OOP as that will help point you in the right direction as to how to build data models, collections, etc.
Below is an example of service class to manage your data.Note I have not tested this code but it should give you a start.
EXAMPLE:
(function () {
'use strict';
ArticleController.$inject = ['$scope', 'Article'];
function ArticleController($scope, Article) {
var vm = this,
getArticles = function () {
return Article.getArticles()
.then(function (result) {
if (result) {
return vm.articles = result;
}
});
};
vm.getArticles = getArticles;
vm.articles = {};
// OR replace vm.articles with $scope if you prefer e.g.
$scope.articles = {};
$scope.userNgClickToInit = function () {
vm.getArticles();
};
// OR an init on document ready
// BUT to honest I would put all init logic in service class so all in calling is init in ctrl and model does the rest
function initArticles() {
vm.getArticles();
// OR chain
vm.getArticles()
.then(getCategories); // doesn't here, just an example
}
initArticles();
}
ArticleModel.$inject = ['$scope', '$http', '$q'];
function ArticleModel($scope, $http, $q) {
var model = this,
URLS = {
FETCH: 'data/articles.json'
},
articles;
function extract(result) {
return result.data;
}
function cacheArticles(result) {
articles = extract(result);
return articles;
}
function findArticle(id) {
return _.find(articles, function (article) {
return article.id === parseInt(id, 10);
})
}
model.getArticles = function () {
return (articles) ? $q.when(articles) : $http.get(URLS.FETCH).then(cacheArticles);
};
model.getArticleById = function (id) {
var deferred = $q.defer();
if (articles) {
deferred.resolve(findArticle(id))
} else {
model.getBookmarks().then(function () {
deferred.resolve(findArticle(id))
})
}
return deferred.promise;
};
model.createArticle = function (article) {
article.id = articles.length;
articles.push(article);
};
model.updateArticle = function (bookmark) {
var index = _.findIndex(articles, function (a) {
return a.id == article.id
});
articles[index] = article;
};
model.deleteArticle = function (article) {
_.remove(articles, function (a) {
return a.id == article.id;
});
};
}
angular.module('app.article.model', [])
.controller('ArticleController', ArticleController)
.service('Article', ArticleModel);
})()

AngularJS - Factory not working/activating

I am trying to work with AngularJS and a Web API written in VB.NET (Doing this for my internship).
I have my angularApp defined, same for my controller and factory.
I'm also working with the routing from Angular and this works perfectly.
The issue I'm dealing with is that my factory isn't activated or isn't working.
Please take a look at the code below:
My AngularApp.js
var angularApp = angular.module('AngularApp', ['ngRoute']);
angularApp.config(['$routeProvider',
function ($routeProvider) {
$routeProvider
.when('/ExpenseOverview', {
controller: 'ExpenseController',
templateUrl: 'Views/ExpenseOverview.aspx'
})
.when('/AddExpense',
{
controller: 'ExpenseController',
templateUrl: 'Views/AddExpense.aspx'
})
.otherwise({ redirectTo: '/ExpenseOverview' });
}]);
My ExpenseController:
angular.module("AngularApp").controller("ExpenseController", ["$scope", "ExpenseFactory", function ($scope, ExpenseFactory) {
//variabelen
$scope.expenses = [];
$scope.id = 0;
$scope.date = "";
$scope.type = "";
$scope.title = "";
$scope.project = "";
$scope.status = "";
$scope.img = "";
var shown = false;
var dataURL = "";
ExpenseFactory.getList($scope);
}]);
So far my controller isn't doing much more other than retrieving a list of data from the database through the web API.
My ExpenseFactory.js
angular.module("AngularApp").factory("ExpenseFactory", ["$http", function ($http) {
alert("test factory");
var factory = {};
//lijst van expenses ophalen
factory.getList = function ($scope) {
$http.post("/api/Expense/List")
.success(function(data) {
if (data === undefined || data == "") {
data = [];
}
$scope.expenses = data;
$scope.id = $scope.expenses[$scope.expenses.length - 1].Id + 1;
})
.error(function() {
alert("Er is een fout opgetreden");
});
};
factory.saveList = function(expenseList) {
$http.post("/api/Expense/SaveList", { 'expenses': expenseList })
.success(function() {
alert("Expenses have been saved succesfully!");
})
.error(function() {
alert("Something went wrong while saving the expenses");
});
};
return factory;
}]);
As you can see, I have put an alert as the first line of code in the factory. This alert isn't even popping up, which means the factory isn't activating/working.
What is failing in this code?
EDIT
I updated my code to the current version with all the comments about things that might be interfering with the code. I can confirm that none of this was working, so the error is occuring somewhere else.
Another note: I'm working with Visual Studio 2012, if this might have something to do with it, please do elaborate how I can fix this shenannigans.
You missed to return $http promise from factory methods
factory.getList = function ($scope) {
return $http.post("/api/Expense/List")
.success(function(data) {
if (data === undefined || data == "") {
data = [];
}
$scope.expenses = data;
$scope.id = $scope.expenses[$scope.expenses.length - 1].Id + 1;
})
.error(function() {
alert("Er is een fout opgetreden");
});
};
factory.saveList = function(expenseList) {
return $http.post("/api/Expense/SaveList", { 'expenses': expenseList })
.success(function() {
alert("Expenses have been saved succesfully!");
})
.error(function() {
alert("Something went wrong while saving the expenses");
});
};
Rather than passing whole scope, you should create one model object like $scope.model = {} and that will hold the all value of ng-model (scope variables) don't pass whole scope to factory, Pass only relevant data to service method.
As the app, controller and factory are in different files, it's better to avoid referencing the module using angularApp.
Instead use the following syntax:
angular.module('AngularApp').factory("ExpenseFactory", ["$http", function ($http) {
Here,
angular.module('AngularApp')
Means you're getting the module.
If you're going to use var angularApp, you're actually polluting the global namespace with your variable name.
Also if by chance in some other library code, someone reassigns it to something else then your entire application will break.
for example:
in another file, `angularApp = alert;`
And one more thing,
In your controller:
angularApp.controller("ExpenseController", ["$scope", "ExpenseFactory", function ($scope, expenseFactory) {
You have a typo in expenseFactory as it must be ExpenseFactory
angularApp.controller("ExpenseController", ["$scope", "ExpenseFactory", function ($scope, ExpenseFactory) {
Thank you #mohamedrias for helping me find to solution.
It was indeed because of the URL Path that was invalid.
Because of the view that couldn't be loaded, the factory was crashing alongside it.
I don't know how this happened, but it's fixed now!
All the code was correct, except for a reference to an invalid URL path for my views.
Thanks for all the help and comments, I'll keep everything in mind for the upcoming parts of my project.
StackOverflow is awesome!

Categories