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Angular JS : how can I load the factory only once?

I am using a static json file to simulate my server and getting my array of orders from it.
I'm presenting the orders in a table in my html file with the option of deleting one from it.
Each time I load the html file the full list gets loaded, with the orders I have deleted throught the controller function.
How can I loat the data from the factory only once?
Here is my controller:
app.controller("MainPageCtrl", function($scope, getOrdersFactory)
{
$scope.orders = [];
// Getting the data frm the facrory
var dataPromise = getOrdersFactory.getDataFunc();
dataPromise.then(function(data){
$scope.orders = data.orders;
});
// Deletes an orders.
$scope.deleteOrder = function(order){
// Finds the index of the order.
var orderIndex = $scope.orders.indexOf(order);
// Delete the order.
$scope.orders.splice(orderIndex, 1);
};
});

By default angular services and factories are singletons(loaded only once). The problem you are facing is with controller re-initialization. When route change happens the controller is re-initialized so therby getting the previous value from the factory.
You can use a setter function on your 'getOrdersFactory'.
Assuming your 'getOrdersFactory' to be
app.factory('getOrdersFactory',function(){
//code to read from file and set the file on a variable orderDetails
var orderDetails = contentsReadFromFile;
return{
getDataFunc:function(){
return orderDetails
},
setDataFunc:function(modifiedOrderDetails){
orderDetails = modifiedOrderDetails;
//code to set the new content to the static file
}
}
}
code to read the file from the static file will be rendered when you inject the factory for the first time, and on your controller set the order details on the delete function
// Deletes an orders.
$scope.deleteOrder = function(order){
// Finds the index of the order.
var orderIndex = $scope.orders.indexOf(order);
// Delete the order.
$scope.orders.splice(orderIndex, 1);
getOrdersFactory.setDataFunc($scope.orders);
};

I guess you are losing your data i.e $scope.orders .If this is the scenario just change
dataPromise.then(function(data){
$scope.orders = data.orders;
});
to
dataPromise.then(function(data){
$scope.orders = angular.copy(data.orders);
});

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);
})()

Select websql Data using Angular JS

I am trying to figure this out the best way to do this. I am trying to insert data into a WebSQL table and then select the data from the table and display on the screen using ng-repeat. I am using this Angular WebSQL Module https://github.com/paulocaldeira17/angular-websql#select-all.
So far, I can get the remote data and insert them into the local database. When I try to call the insert data, $scope.localproducts shows an empty array - console.log( $scope.localproducts) shows an empty array.
I use localproducts scope for my ng-repeat.
I can't get to return the ProductsFactory.localproducts array to my controller from the Factory's selectAllData function.
When clicks a button on my page, it calls the insertData function in my Controller.
What have I done wrong here? I am pretty new to angular so I would very much appreciate if someone can help me to improve the below code or suggest if there is a better way to do this.
.controller('DownloadProductsCtrl', ['$scope','ProductsFactory', function ($scope, ProductsFactory){
$scope.products = ProductsFactory.products;
$scope.localproducts = ProductsFactory.localproducts;
$scope.insertData = function(){
ProductsFactory.getRemoteData().then(function(results){
$scope.localproducts = ProductsFactory.localproducts;
console.log( $scope.localproducts); //This shows an empty array
});
}; }])
.factory('ProductsFactory', ['$webSql', function($webSql){
db = $webSql.openDatabase('myappdb', '1.0', 'Test DB', 2 * 1024 * 1024);
ProductsFactory = {};
ProductsFactory.products = [];
ProductsFactory.localproducts = [];
ProductsFactory.getRemoteData = function () {
return $http.get('./products/list.json')
.success(function (data) {
ProductsFactory.products = data;
ProductsFactory.insertData(data);
})
.error(function () {
console.error('Error');
});
};
ProductsFactory.insertData = function (data){
angular.forEach(data, function(value, key) {
db.insert('products', value).then(function(results) {
<!-- In here I like to count the total inserted items and display it on the page, but not sure sure how to send it to a scope in my controller -->
});
});
ProductsFactory.selectAllData();
};
ProductsFactory.selectAllData = function(){
db.selectAll("products").then(function(results) {
for(var i=0; i < results.rows.length; i++){
ProductsFactory.localproducts.push(results.rows.item(i)); //This added data to the array successfully.
}
console.log(ProductsFactory.localproducts); //This shows an empty array
});
};
return ProductsFactory;
}]);

Try with this resource as a start point.
https://gist.github.com/jgoux/10738978
https://github.com/paulocaldeira17/angular-websql/blob/master/angular-websql.js
The first one is very basic and easier to understand. The second more involved.

Accessing Fetched Resources From a Controller?

In my AngularJS controller I'm trying to do something relatively simple: I'm trying to populate a <select> element dynamically in the controller. To do so I need to wait for my localized UI text data to be loaded and data from my server to be loaded and this is causing a problem for me.
What my HTML Looks like:
<select
data-ng-model="group"
data-ng-options="options.value as options.label for options in userGroups">
<option>--</option>
</select>
Then my controller is actually implementing a base controller "class" which allows me to share logic between controllers:
// exampleController.js
myModule.controller('exampleController',
['$scope', '$timeout', '$routeParams', '$controller',
function ($scope, $timeout, $routeParams, $controller) {
// Instantiate the base controller class and set it's scope
// to this controller's scope. This is how the base and child
// controllers will share data and communicate.
var base = $controller('baseController', { $scope: $scope });
}]);
And here is a relevant snippet of the baseController:
// baseController.js
$scope.getDataFromUrl = function (url, cache, successFunction) {
$http.get(url, { cache: cache })
.success(function (data) {
if (!handleErrorInData(data))
{
successFunction(data);
}
});
};
$scope.getDataFromUrl(uiTextResourceUrl, true, function (data) {
$scope.uiText = data;
});
So baseController fetches the text resources when it loads and sets it to the scope when it's finished retrieving the data. exampleController on the other hand will fetch other data from the server via the getDataFromUrl() function defined in baseController like so:
$scope.getDataFromUrl(dataUrl, false, function (data) {
// Do stuff with the returned data...
};
My issue is coming from this part of the exampleController code where I populate the data of the <select> element from earlier:
// exampleController.js (Continued...)
$scope.getDataFromUrl(userGroupsUrl, false, function (data) {
initSelectDropdown(data);
});
var initSelectDropdown = function (data) {
var userGroups = [];
// Parse data retrieved from the server and populate the <select> bound data
// array with it
var index;
for (index = 0; index < data.length; ++index)
{
var newGroup = {
value: data[index],
label: data[index]
};
// One of the data entries will have a value of "", this group needs its
// label to be set to the localized string "No Group"
if (newGroup.value === "")
{
newGroup.label = '<' + $scope.uiText['NoGroup.Text'] + '>';
}
userGroups.push(newGroup);
}
// Set local userGroups to scope
$scope.userGroups = userGroups;
};
The problem I'm having is here in the initSelectDropdown() function. I need to have both the data from the server and the uiText resource data from the server, particularly the line newGroup.label = '<' + $scope.uiText['NoGroup.Text'] + '>'; where the data is being transformed in a way that is dependant on localized resources being loaded. I researched the issue and saw that using $q.all() might be a solution but unfortunately in my case there is no way for me to call $q.all() because the two calls to fetch data are being made from different functions in different controllers (data being requested from child controller and resources being requested from base controller).
In the view it's easy to fix this because if I bind an element to $scope.uiText['SomeText.Text'] then it doesn't care if SomeText.Text is undefined at first and when it is eventually populated the UI will automatically pick up on the change.
How can I make this work? Is it possible to achieve something like how binding works in the view?

For sharing code angular provides services/factory, you don't need to use base controller.
Define a factory class and add two methods, one to fetch your server data and other to fetch uiText data. these methods will return promises.
Now in your controller you can use $q.all() passing the two promises that will be resolved when ajax call is complete.
Hope it makes sense ?