Creating a function in Angular - javascript

I have two controllers both with a save button which essentially does the same thing. So I want to put it in a reusable function that both the controllers can use. I have tried to do this by creating a normal function and passing the model object, as well as $http, but the function is executing before the save button is pressed leading to all the params being set to undefined. What way should I create a function that both these controllers can use?
Here how code looks:
app.controller('addCtlr',['$scope','$http','$location',
function($scope, $http, $location){
$scope.save = function(){
var practices = [];
var url = "https://maps.googleapis.com/maps/api/geocode/json?address="+$scope.location.address.replace(/ /g,"+");
//If there are practices
if($scope.days){
for(dayName in $scope.days){ //Loop through the days object
var day = $scope.days[dayName]; //Gets the day pratice object
practices.push({day: dayName, start_time: day.startTime, end_time: day.endTime}); //Add the pratice object to the practices array
}
}
//Call to get the lat lng and formatted address from Google Map's service
$http.get(url)
.then(function(response){
locJSON = response.data.results[0]; //The JSON response
//createing an object to send to the backend to save
var locObj = {
name: $scope.location.name,
address: locJSON.formatted_address,
location: locJSON.geometry.location,
cost: $scope.location.cost,
practices: practices,
notes: $scope.location.notes
};
//Sending using POST since a new object is being created
$http.post('/api/locations', locObj)
.then(
$location.path('/')
);
});//*/
};
}]);
This is how my function looked:
function saveLocation(location, days, $http){
var practices = [];
var url = "https://maps.googleapis.com/maps/api/geocode/json?address="+location.address.replace(/ /g,"+");
//If there are practices
if(days){
for(dayName in days){ //Loop through the days object
var day = days[dayName]; //Gets the day pratice object
practices.push({day: dayName, start_time: day.startTime, end_time: day.endTime}); //Add the pratice object to the practices array
}
}
//Call to get the lat lng and formatted address from Google Map's service
$http.get(url)
.then(function(response){
locJSON = response.data.results[0];
//createing an object to send to the backend to save
var locObj = {
name: location.name,
address: locJSON.formatted_address,
location: locJSON.geometry.location,
cost: location.cost,
practices: practices,
notes: location.notes
};
//Sending using POST since a new object is being created
$http.post('/api/locations', locObj)
.then(
//$location.path('/') //Redirects the user back to the homepage
);
});
}
This is how I was calling the function in the new controller:
app.controller('addCtlr',['$scope','$http','$location',
function($scope, $http, $location){
$scope.save = saveLocation(location, days, $http);
}]);

You can use service for this. Service is a singleton so will be created only one instance. And You can inject it by a dependency injector to controllers. You can read more here

You can create a service for your shared functionality and can inject it into your controller like below
var app=angular.module('app',[])
app.service('myService',function($http){
this.saveLocation=function(){
//Your code
}
});
and then in your controller you can inject it like below
app.controller('myController',['$scope','myService',function($scope,myService){
//use myService function to call save functionality
}]);
Also if you are using $http, you should keep this in mind that it returns a promise so you need to write all the code which is dependent on the value of this promise in a success callback otherwise your code will run before this callback and you will have undefined values for those variables.

Use a factory() service. You can define a set of functions and return them as an object. This object can then be injected within any controller:
app.factory('sharedFactory', [function() {
"use strict";
return {
myFunction: function() {
console.log("sharedFunction");
}
};
}]);
app.controller('AnyController', ['sharedFactory', function(sharedFactory) {
"use strict";
sharedFactory.myFunction();
}]);

Related

Do async calls in services block component load in angularjs?

The angularjs guide contains an example detailing an async call in a service.
The following code is given
angular.module('finance3', [])
.factory('currencyConverter', ['$http', function($http) {
var currencies = ['USD', 'EUR', 'CNY'];
var usdToForeignRates = {};
var convert = function(amount, inCurr, outCurr) {
return amount * usdToForeignRates[outCurr] / usdToForeignRates[inCurr];
};
var refresh = function() {
var url = 'https://api.exchangeratesapi.io/latest?base=USD&symbols=' + currencies.join(",");
return $http.get(url).then(function(response) {
usdToForeignRates = response.data.rates;
usdToForeignRates['USD'] = 1;
});
};
refresh();
return {
currencies: currencies,
convert: convert
};
}]);
Since the refresh function is async, how does angularjs ensure that the data is loaded before loading the controller which accesses the data returned by the refresh function, ie the data contained in the usdToForeignRates object.
I assume there is some blocking going on somewhere, otherwise when the controller accesses the object returned, it will get undefined values.
I want to understand the flow, does angular internally ensure that service loads before injecting it into the controller?

Best way to pass variables between controllers

I am using three Angular controllers:
**Controller1**
var fetchStudentDetails = function(){
var sDetails = myService.getList(//url-1 here);
sDetails.then(function (data) {
$scope.studentData = data.list;
var studentId = $scope.studentData[0].id;
});
}
fetchStudentDetails();
$scope.loadSecondLevel = function(){
$state.go('secondLevel');
}
**Controller2**
var fetchClassDetails = function(){
var sDetails = myService.getList(//url-2 here);
sDetails.then(function (data) {
$scope.classData = data.list;
var className = $scope.classData[0].name;
});
}
fetchClassDetails();
$scope.loadThirdLevel = function(){
$state.go('thirdLevel');
}
**Controller3**
$scope.putStudentDetails = function(){
// Here I need studentId,className for updateResource
var sDetails = myService.updateResource(//url-3 here);
sDetails.then(function (data) {
});
}
Where I have to pass studentId (in Controller1), className (in Controller2) into a function which in Controller3. I tried with $rootScope, it is working but when refresh the page $rootScope values become empty. Does anyone know how to do this?
Your question could be split into two aspects:
1. How to share data between controllers
The best practice to share data in Angular 1.x is using factory, store the shared data in a factory service, and expose access methods to controllers:
factory('DetailData', function(myService, $q){
var _details;
function __getDetailData(){
return details
}
function __setDetailData(){
return myService.getList().then(function(data){
_details = data;
})
}
return {
getDetailData: __getDetailData,
setDetailData: __setDetailData
}
})
controller('myContrller', function(DetailData, $scope){
$scope.data = DetailData.getDetailData();
})
2. How to persist data when page refreshed,
you can use localStorage to keep data persistent during page reloading, many tools & libraries can achieve this, for example ngStorage, or you could reset the data from server every time your angular application started:
//this would register work which would be performed
//when app finish loading and ready to start.
angular.module('app').run(function(DetailData){
DetailData.setDetailData();
})
Depending on what problem you are solving.
There are three options:
Is to save data to $rootScope
Is to use $scope.$emit & $scope.$on functions.
Use a custom Service to store the data
And if you need to save data, so it was available after full page reload - localStorage.
Hey this question are responded in Passing data between controllers in Angular JS?
But the simple response is in the services.

Can't pass data between controllers?

I don't get what I'm doing wrong, I am trying to globally store and pass data from one controller to another via a service. I stored the data in one controller and confirmed that it was stored at the beginning of my buildReportController. Then, when I click a button on my UI, it opens reportResultsController. However, issue is, I can store the data correctly in buildReportController via locationHistoryService.store() but when I go to reportResultsController and calllocationHistoryService.get(), thepreviousLocationvariable inlocationHistoryService` is empty as if the data was never set. Any ideas on how why or how I can "globally" store data and pass it between controllers? Below is my attempt. Thanks!
In reportView.js
angular.module('reportView', [])
.service('locationHistoryService', function(){
var previousLocation = "";
return {
store: function(location){
previousLocation = location;
},
get: function(){
return previousLocation;
}
};
});
In buildReport.js
angular.module('buildReport', ['reportView'])
.controller('buildReportController', ['$rootScope', 'locationHistoryService'], function($rootScope, locationHistoryService){
$rootScope.$on('$locationChangeSuccess', function(e, newLocation, oldLocation){
locationHistoryService.store(oldLocation);
console.log("Old location: ", oldLocation);
});
}
In reportResults.js
angular.module('reportResults', ['reportView'])
.controller('reportResultsController', ['$rootScope', 'locationHistoryService'], function($rootScope, locationHistoryService){
console.log("location : ", locationHistoryService.get());
}
The locationHistoryService.get() method in reportResults.js is called before it is set in buildReport.js.
It would be better if you announce when the previousLocation variable has been set.
In reportView.js
angular.module('reportView', [])
.service('locationHistoryService',['$rootScope'] ,function($rootScope){
var previousLocation = "";
return {
store: function(location){
previousLocation = location;
$rootScope.$broadcast('previous-location-set');
},
get: function(){
return previousLocation;
}
};
});
In reportResults.js
angular.module('reportResults', ['reportView'])
.controller('reportResultsController', ['$rootScope', 'locationHistoryService'], function($rootScope, locationHistoryService){
$rootScope.$on('previous-location-set', function(){
console.log("location : ", locationHistoryService.get());
});
}
Your webapp should have only one module which is automatically bootstrapped by angular, and other modules as dependencies. The syntax of writing service is incorrect. You wrote .service but returning object which .factory should return. Here is working example of your code http://codepen.io/Chyngyz/pen/NxbdpW?editors=101
Also you wrote the safe for minification syntax of controllers incorrect, the function block of controller should be the last item in the array.

Angular Cache $resource Result

I'm looking for a way to cache language translation in angular js application.
In the application, there are many form that need translation. To get the available languages, I use $resource to get them from our Language API.
First, I create an empty array of languages on application run()
angular
.module('admin', [])
.run(['$rootScope',
function($rootScope) {
$rootScope.languages = [];
}
)
;
Then I create a service to handle translation and language query
angular
.module('admin')
.factory('Utils', ['$rootScope', 'Language',
function($rootScope, Language) {
var utils = {};
utils.getLanguages = function() {
if ($rootScope.languages.length > 0) {
return $rootScope.languages;
}
var languages = Language.query(function(data) {
$rootScope.languages = data;
});
return languages;
}
return utils;
}
)
;
and in the controller
angular
.module('admin')
.controller('CategoryController', ['$scope', 'Utils',
function($scope, Utils) {
$scope.languages = Utils.getLanguages();
}
])
;
That's the way I cache the $resource result.
What do you think about this solution?
Is it ok to cache in $rootScope?
The reason I want to cache the result because I need the languages in most of the controller, so I don't want to make request for the Language API everytime I access a new state.
There as some improvement that you can do with your implementation.
You don't need to use $rootScope for saving language and then exposing it through a service. You can very well use a service and cache the results in the service.
Something like this should be better option
angular.module('admin')
.factory('LanguageCache', ['$rootScope', 'Language',
function ($rootScope, Language) {
var service = {};
var cache;
service.getLanguages = function () {
if (cache) {
return cache;
}
var languages = Language.query(function (data) {
cache = data;
});
return cache;
}
return service;
});
This way the language cache will be available for services that want it. It will not pollute the global $rootScope object.

save $location parameters state AngularJS

How do I save URL parameters state throughout lifecycle of application using pushState?
Page load.
Go to "/search" via href
submitSearch() through filter fields where $location.search(fields)
Go to "/anotherPage" via href
Go back to "/search" via href
Search paramters are set back to what they last were.
Is this a built in feature somewhere?
If not what's the best way to go about this?
If you're planning on a mostly single page website through pushState, you might want to get an intimate understanding of $routeProvider (http://docs.angularjs.org/api/ngRoute.%24routeProvider).
To go further down the rabbit hole, I would recommend looking at the ui-router module: (https://github.com/angular-ui/ui-router). $stateProvider (from ui-router) and $routeProvider work very similar, so sometimes the ui-router docs can give insights that you can't find in the poor documentation of the $routeProvider.
I reccomend going through the five page ui-router documentation (https://github.com/angular-ui/ui-router/wiki) page by page.
After all that preamble, here's the practical: you would set up a factory that holds history data and use the controller defined in your $routeProvider/$stateProvider to access and manipulate that data.
Note: the factory is a service. A service is not always a factory. The namespace goes:
angular.module.<servicetype[factory|provider|service]>.
This post explains the service types: https://stackoverflow.com/a/15666049/2297328. It's important to remember that they're all singletons.
Ex:
var myApp = angular.module("myApp",[]);
myApp.factory("Name", function(){
return factoryObject
});
The code would look something like:
// Warning: pseudo-code
// Defining states
$stateProvider
.state("root", {
url: "/",
// Any service can be injected into this controller.
// You can also define the controller separately and use
// "controller: "<NameOfController>" to reference it.
controller: function(History){
// History.header factory
History.pages.push(History.currentPage);
History.currentPage = "/";
}
})
.state("search", {
url: "/search",
controller: function(History, $routeParams) {
History.lastSearch = $routeParams
}
});
app.factory('<FactoryName>',function(){
var serviceObjectSingleton = {
pages: []
currentPage: ""
lastSearch: {}
}
return serviceObjectSingleton
})
If you're wondering what the difference between $routeProvider and $stateProvider is, it's just that $stateProvider has more features, mainly nested states and views... I think.
The easiest way is using cookies, angularjs provides a wrapping service for that.
Simply when you go to "/search" save your current URL parameters with "$cookieStore.put()" and once you've back you've got what you need with "$cookieStore.get()".
See the documentation at angularjs cookie store
I made a locationState service, you simply give it the values you want to persist and it stores them in the URL. So you can store all the state you want across all routes in your app.
Use it like this:
angular.module('yourapp')
.controller('YourCtrl', function ($scope, locationState) {
var size = locationState.get('size');
;
// ... init your scope here
if (size) {
$scope.size = size;
}
// ...and watch for changes
$scope.$watch('size', locationState.setter('size'));
}
Here's the code:
// Store state in the url search string, JSON encoded per var
// This usurps the search string so don't use it for anything else
// Simple get()/set() semantics
// Also provides a setter that you can feed to $watch
angular.module('yourapp')
.service('locationState', function ($location, $rootScope) {
var searchVars = $location.search()
, state = {}
, key
, value
, dateVal
;
// Parse search string
for (var k in searchVars) {
key = decodeURIComponent(k);
try {
value = JSON.parse(decodeURIComponent(searchVars[k]));
} catch (e) {
// ignore this key+value
continue;
}
// If it smells like a date, parse it
if (/[0-9T:.-]{23}Z/.test(value)) {
dateVal = new Date(value);
// Annoying way to test for valid date
if (!isNaN(dateVal.getTime())) {
value = dateVal;
}
}
state[key] = value;
}
$rootScope.$on('$routeChangeSuccess', function() {
$location.search(searchVars);
});
this.get = function (key) {
return state[key];
};
this.set = function (key, value) {
state[key] = value;
searchVars[encodeURIComponent(key)] = JSON.stringify(value);
// TODO verify that all the URI encoding etc works. Is there a mock $location?
$location.search(searchVars);
};
this.setter = function (key) {
var _this = this;
return function (value) {
_this.set(key, value);
};
};
});

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