Wait for server data in order to initialize service - angularjs

I want to create an angular service that when the app is loaded for the first time will fetch data from the server once and then I'll be able to query the data from the local service object. Here's how I tried to do it:
angular.module('my.services').factory('Properties', function ($http) {
var properties = $http.get("/properties");
return {
get: function (property) {
// Logic here
console.log(property);
}
}
});
Problem is - $http.get() is asynchronous and in order to achieve what I'm trying to do, I have to use it synchronously. Is there a way to do it with "native" AngularJS? Or I must use an XHR call for this?

You can try to do something like this
angular.module('my.services').factory('Properties', function ($http) {
var propertiesPromise = $http.get("/properties");
return {
get: function (property) {
propertiesPromise.then(function(properties){
console.log(properties);
});
}
}
});

Related

Simple service based on Observable with Angular 1.5

I would like to use Rxjs in my project which is based on Angular 1.5 and written in ECMA 5. I would like to rewrite my service methods which are based on promises and want implement Observables.
I write sth like this in my service:
function service(Restangular) {
var self = this;
self.user = new Rx.Subject();
var service = {
artistStream: artistStream,
};
function artistStream(artist) {
self.user.onNext({
data : Restangular
.all('text/')
.customGET('search', {q : artist})
});
}
return service;
}
And then I tried use this service in my component like this :
function testRx(artist) {
console.log(artistService.artistStream(artist));
}
I get error from console :
TypeError: self.user.onNext is not a function
What I'm doing wrong? It is my first time when I use Observables
Ok, rewrite service and work properly.
function artistStream(artist) {
const promise = Restangular
.all('text/')
.customGET('search', {q : artist})
const subscription = Rx.Observable.fromPromise(promise);
return subscription;
}

how to retrieve ajax response value from service?

I am using 2 service in controller
First Service is to get AjaxResponse where logic to fetching the response is mentioned
The second Service calls the first service to make Http request and get result and then, in turn, return it to the controller
Ctrl Dependency injected firstService,secondService
this.getService = secondService.getData(param);
First Service--> firstService
this.httpResponse(param){
var re = $http.get(param);
return re.then(success,fail);
}
function success(data){
return data;
}
function fail(data){
console.log(data);
}
Second Service (Dependency injection of First Service)
function secondService(firstService){
this.getData = function(param){
return firstService.httpResponse(param);
};
}
this.getService is coming as undefined, all the call are going properly.
Even tried the following code:
secondService.getData(param).then(function(data){console.log(data);});
That doesn't help either.
You should chain the promises in these kinds of situations.
First, you define your service. It should contain two distinct functions. As an example, I did a GET and a POST.
angular.module("myApp",[]).factory("SharedServices", function($http) {
return {
getItem: function() {
return $http.get('path/to/api');
},
postItem: function(payload) {
return $http.post('path/to/api', payload);
}
};
});
Then, reference the service in your controller. getItem() will return a promise, where you can use it using .then to call your second service in the success callback.
angular.module("myApp",[]).controller("MainCtrl", function($scope, SharedServices) {
SharedServices.getItem().then(function(response) {
//success, got something
//call the second part
var payload = { myPayload: response.data.someItem };
SharedServices.postItem(payload).then(function(response) {
//success
}, function(response) {
//an error has occurred to the second call--POST
});
}, function(response) {
//an error occurred to the first call--GET
});
});
Used Callback to get the result.It is similar to deferred(promise)

calling breeze from angular - service or controler - syntax please

I have an angular project. I am making an html/angular form - getting the data from a stored procedure via $http get in a service in angular. Now I want to databind some of the drop down lists in my filter that's in this html form. I have the data in a view which I made models for and added to the entity framework. How should I make calls to this breeze in angular? Code example please? in service or in controller?
------here's what i've tried--------------
what am I doing wrong here? (may be a few things...i'm new to angular. Then I just want to be able to somehow call this function populatestyleddl in my ng-model or something....
.factory('sellingService', ['$filter', '$http', function ($filter, $http) {
function PopulateStyleDDL() {
return breeze.EntityQuery.fromEntityNavigation('v_Style')
.using(context.manager).execute();
};
//check if above function is legal
function SalesStatus(filter) {
console.log(breeze);
return $http({
method: 'GET',
url: '/Services/SalesStatus',
params: { filter.itemStyle }
}).then(function (result)
{ return result.data; })
}
return {
SalesStatus: SalesStatus
};
}]);
--------------------------------here's what i have now.....
ok, here is what i've got now. this is happening in a js file where all my breeze calls are. Can you confirm if my syntax here is right and how my function syntaxically should look in my factory (and also how my syntax should look in my controller...)
function GetStyles() { return breeze.EntityQuery .from("v_Style") .using(manager) .execute(); }
#LisaSolomon, regarding your syntax:
function GetStyles() {
return breeze.EntityQuery
.from("v_Style")
.using(manager)
.execute();
}
Looks good with the information I have. If it's not working I'd make sure:
The controller has a properly-defined v_Style action, and
The manager is defined and has the correct service name
So, assuming that is correct, you will need to add it to your returned object so that it is available in your controller:
return {
SalesStatus: SalesStatus,
GetStyles: GetStyles
};
Then to use it in your controller, you will need to reference the .then() of the promise
$scope.styles = '';
sellingService.GetStyles().then(function(data) {
$scope.styles = data.results;
}).catch(function(err) {
// error processing
});
Any error messages you're getting would be helpful. If there's any chance you could show controller and view code so we could build a fiddle, that would be great, too.

How to communicate with server using AngularJS within Google Apps Script

Recently it has become possible to use angularjs within google apps script via the iframe sandbox mode.
My problem comes when trying to communicate with the server (gapps spreadsheet) and receiving asynchronous data in return.
The implementation for receiving data from the server is to use a function with a callback function like so:
google.script.run.withSuccessHandler(dataGatheringFunction).getServerData();
getServerData() would be a function that resides server-side that would return some data, usually from the accompanying spreadsheet. My question is how to use the callback function within the parameters of AngularJS. A typical $http function could be placed in a provider, and the scope value could be populated after then.() returns. I could also invoke $q. But how would I deal with the necessity of google's callback?
Here's a simplified version of what I'm messing with so far:
app.factory("myFactory", function($q){
function ssData(){
var TssData = function(z){
return z;
}
google.script.run.withSuccessHandler(TssData).getServerData();
var deferred = $q.defer();
var d = deferred.resolve(TssData)
console.log("DP: " + deferred.promise);
return deferred.promise;
}
return ssData();
})
Then in the controller resolve the server call similar to this:
myFactory.then(set some variables here with the return data)
My question is simply - How do I deal with that callback function in the provider?
The script throws no errors, but does not return the data from the server. I could use the old $timeout trick to retrieve the data, but there should be a better way.
You only need to $apply the output from the server function:
google.script.run.withSuccessHandler(function(data) {
$scope.$apply(function () {
$scope.data = data;
});
}).withFailureHandler(errorHandler).serverFunction();
Maybe the most elegant solution that makes sure the google.script.run callbacks are registered automatically in the AngularJS digest cycle would be to use the $q constructor to promisify the google callbacks. So, using your example above:
app.factory('myFactory', ['$q', function ($q){
return {ssData: ssData};
function ssData(){
var TssData = function(z){
return z;
};
var NoData = function(error) {
// Error Handling Here
};
return $q(function(resolve, reject) {
google.script.run
.withSuccessHandler(resolve)
.withFailureHandler(reject)
.getServerData();
}).then(TssData).catch(NoData);
}
}]);
Then in your controller you can call myFactory.ssData()
Since I don't know exactly what TssData is doing I included it here but note that this simply returns another promise in this context which you will still have to handle in your controller:
myFactory.ssData().then(function(response) {
// Set data to the scope or whatever you want
});
Alternately, you could expose TssData by adding it to the factory's functions if it is doing some kind of data transformation. If it is truly just returning the response, you could refactor the code and omit TssData and NoData and handle the promise entirely in the controller:
app.factory('myFactory', ['$q', function ($q){
return {ssData: ssData};
function ssData(){
return $q(function(resolve, reject) {
google.script.run
.withSuccessHandler(resolve)
.withFailureHandler(reject)
.getServerData();
});
}
}]);
app.controller('myController', ['myFactory', function(myFactory) {
var vm = this;
myFactory.ssData()
.then(function(response) {
vm.myData = response;
}).catch(function(error) {
// Handle Any Errors
});
}]);
An excellent article about promises (in Angular and otherwise) is here: http://pouchdb.com/2015/05/18/we-have-a-problem-with-promises.html
This guy seems to be pulling data from a GSheet into angular quite happily without having to do anything fancy.
function gotData(res) {
$scope.validUser = res.validUser;
var data = angular.copy(res.data), obj, i=0;
Object.keys(data).forEach(function(sh) {
obj = {title: sh, checked: {}, showFilters: false, search: {}, sort: {index: 0, reverse: false}, currentPage: 0, checkedAll: true, showBtns: true, searchAll: ''};
obj.heading = data[sh].shift();
obj.list = data[sh];
obj.heading.forEach(function(s,i) {
obj.checked[i] = true;
});
$scope.sheets.push(obj);
});
$scope.sheets.sort(function(a,b) {
return a.title > b.title ? 1 : -1;
});
$scope.gotData = true;
$scope.$apply();
}
google.script.run.withSuccessHandler(gotData).withFailureHandler($scope.gotError).getData();
My solution was to get rid of the $q, promise scenario all together. I used $rootScope.$broadcast to update scope variables from the server.
Link to spreadsheet with script.

How can I directly inject $http into a provider?

All I need to do is to download a json file and assign it to OCategories in PCategory provider after I set the path. However I get an error that $http doesnt exist. How can I inject it into my provider and download inside of the setPath function?
var app = angular.module('NSApp',
[
'ui.bootstrap',
'MDItem',
'MDUser',
'MDNotification',
'MDUpload'
]
);
app.config(function(PCategoriesProvider)
{
PCategoriesProvider.setPath('data/csv/categories.json');
});
MDItem/provider/category.js
angular.module('MDItem').provider('PCategories',function(){
var OCategories;
var OPath;
return{
setPath: function(d){
OPath = d;
console.log('Path is set. Trying to download categories.');
OCategories = $http.get(oPath);
},
$get : function() {
return {
categories : OCategories
}
}
}
});
You can never inject service instances into config functions or providers, since they aren't configured yet. Providers exist to configure specific services before they get injected. Which means, there's always a corresponding provider to a certain service. Just to clarify, here's a little example configuring $location service using $locationProvider:
angular.module('myModule').config(function ($locationProvider) {
$locationProvider.html5Mode(true);
});
So what happens here, is that we configure $location service to use its html5mode. We do that by using the interfaces provided by $locationProvider. At the time when config() is executed, there isn't any service instance available yet, but you have a chance to configure any service before they get instantiated.
Later at runtime (the earliest moment ist the run() function) you can inject a service. What you get when injecting a service is what its providers $get() method returns. Which also means, each provider has to have a $get() function otherwise $injector would throw an error.
But what happens, when creating custom services without building a provider? So something like:
angular.module('myModule').factory('myService', function () {
...
});
You just don't have to care about, because angular does it for you. Everytime you register any kind of service (unless it is not a provider), angular will set up a provider with a $get() method for you, so $injector is able to instantiate later.
So how to solve your problem. How to make asynchronous calls using $http service when actually being in configuration phrase? The answer: you can't.
What you can do, is run the $http call as soon as your service gets instantiated. Because at the time when your service get instantiated, you're able to inject other services (like you always do). So you actually would do something like this:
angular.module('myModule').provider('custom', function (otherProvider, otherProvider2) {
// some configuration stuff and interfaces for the outside world
return {
$get: function ($http, injectable2, injectable3) {
$http.get(/*...*/);
}
};
});
Now your custom provider returns a service instance that has $http as dependency. Once your service gets injected, all its dependencies get injected too, which means within $get you have access to $http service. Next you just make the call you need.
To make your this call is getting invoked as soon as possible, you have to inject your custom service at run() phrase, which looks like this:
angular.module('myModule').run(function (custom, injectable2) {
/* custom gets instantiated, so its $http call gets invoked */
});
Hope this makes things clear.
Since all services are singletons in angular you could simply store a variable in a factory with the $http promise. And then when the factory is called at startup it will download the json.
You can then also expose a method on the factory that refreshes the data.
I know this is not the exact answer to your question, but I thought I'd share how I would do it.
angular.module('MDItem').factory('PCategories', function ($http, PCategoriesPath) {
var service = {
categories: [],
get: function () {
if (angular.isUndefined(PCategoriesPath)) {
throw new Error('PCategoriesPath must be set to get items');
}
$http.get(PCategoriesPath).then(function (response) {
service.categories = response.data;
});
}
};
// Get the categories at startup / or if you like do it later.
service.get();
return service;
});
// Then make sure that PCategoriesPath is created at startup by using const
angular.module('MDItem').const('PCategoriesPath', 'data/csv/categories.json');
angular.module('app').controller('myCtrl', function ($scope, PCategories) {
$scope.categories = PCategories.categories;
// And optionally, use a watch if you would like to do something if the categories are updated via PCategories.get()
$scope.$watch('categories', function (newCategories) {
console.log('Look maa, new categories');
}, true); // Notice the true, which makes angular work when watching an array
})
You have to inject $http in the function $get, because that's the function called by the injector.
However, to download the categories you would be better off using promises:
angular.module('MDItem').provider('PCategories',function(){
var OCategories;
var OPath;
return{
setPath: function(d){
OPath = d;
console.log('Path is set');
},
$get : function($http) {
return {
fetch: function () {
var deferred = $q.defer();
$http.get(oPath).then(function (value) {
deferred.resolve(value);
}
return deferred.promise;
}
}
}
}
});
I implemented what I wanted with a diffrent approach which is quite simple and effective. Just add a dummy controller in the main index.html(NOT PARTIAL). Data is now shared between all my modules and controllers and everything is downloaded once. :) Oh I love AJ.
...
<div ng-controller="initController" hidden></div>
...
initController:
angular.module('NSApp',[]).controller("initController",function($scope, $http, FCategory, FLocation){
$http.get('data/json/categories.json').then(function (response) {
FCategory.categories = response.data;
});
$http.get('data/json/cities.json').then(function (response) {
FLocation.cities = response.data;
});
$http.get('data/json/regions.json').then(function (response) {
FLocation.regions = response.data;
});
});
And now you can access it:
angular.module('MDTest', []).controller("test",function($scope, FCategory, FLocation){
$scope.categories = FCategory.categories;
FCategory factory
angular.module('MDItem').factory('FCategory', function ($http) {
var service = {
categories: [],
....
};
return service;
});

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