I've been working on a project for a while on my current job and they're using Angulajs for the front-end. Recently I'm trying to implement the ES6 standard. The project uses a Factory to wrap the API services from the backend like this:
'use strict';
angular.module('products').factory('Products', ['$resource',
($resource)=> {
return $resource('api/products/:productId', {
productId: '#id'
},{
update: {
method: 'PUT'
},
getProductsByType : {
url: 'api/:schoolIdProduct/products/:Type',
params: {
schoolIdProduct: ':schoolIdProduct',
Type: ':Type'
},
isArray: true
}
});
}
]);
So now right now when we call the Factory from the controller I just add the factory and then call the function like this:
$rootScope.supplies = Products.getProducts({
schoolIdProduct: schoolId,
Type: 'Supplies'
});
So when I try to use the arrow function and then() to wait for the response the browser console tells me that is not a function. How do I change my code to use the ES6 standard and get something like this?
Products.getProducts({
schoolIdProduct: schoolId,
Type: 'Supplies'
}).then( (response) =>{
$rootScope.supplies = response;
});
So the thing you are not getting the promise from the response so need to promisify your response either with $q or bluebird.
both solutions are mentioned and you are using ngResource for getting resonses.
angular doc link using $q: https://docs.angularjs.org/api/ng/service/$q
you may also use bluebird library and convert responses using promise library
let promise = new Promise(function (resolve, reject) {
try {
resolve(Products.getProducts({
schoolIdProduct: schoolId,
Type: 'Supplies'
}))
} catch (error) {
reject( error)
}
})
return promise
Related
I am configuring an AngularJS app and am having a little trouble ensuring that my promises are firing before the controllers are loading. My understanding is that this can be done. A bit of code:
First, here's the router code:
$routeProvider
.when('/apage', {
controller: 'APageController',
templateUrl: 'app/apage/apage.view.html',
requiresLogin: true,
resolve: {
"data": function($q, data1Service, data2Service) {
var data1 = data1Service.getData();
var data2 = data2Service.getData();
return $q.all({
data1: data1.$promise,
data2: data2.$promise});
}
}
})
...
Here's one of the service functions (both are similar)...
function getData() {
var deferred = $q.defer();
$http(req)
.success(function(data, status, headers, config) {
// store data ...
deferred.resolve(1); // just a flag to say it worked
$rootScope.$apply();
})
.error(function(data, status, headers, config) {
deferred.resolve(0);
$rootScope.$apply();
});
return deferred.promise;
}
And here's the controller code...
angular
.module('app')
.controller('APageController', APageController);
APageController.$inject = [... 'data'];
function APageController(... data) {
var data1 = data.data1;
var data2 = data.data2;
...
All three are in different files but part of the same module. There must be some concept I'm overlooking. Is there anything apparent here to explain why my resolve promises are not firing?
Thank you.
If you pass in object literal to q.all it will resolve immediately. Instead pass array of promises so that it waits for it to resolve reject. Also .$promise is not needed in your case because you are already returning a promise from your service(based on the displayed code). $promise is generally attached by the object returned by $resource
i.e
return $q.all([data1Service.getData(),
data2Service.getData()]);
and expect data to be array of data resolved from above 2 calls.
or create 2 resolves:
resolve: {
"data": function($q, data1Service, data2Service) {
return data1Service.getData();
},
"data2": function($q, data1Service, data2Service) {
return data2Service.getData();
}
}
and inject data and data2.
otherwise, chain through and change the response format to expect the way you were originally trying to get.
resolve: {
"data": function($q, data1Service, data2Service) {
return $q.all([data1Service.getData(),data2Service.getData()])
.then(function(response){
return {
data1:response[0],
data2:response[1]
};
});
}
}
Do not place rootScope.apply inside your service, it will cause digest already in progress error (since angular will ). $http will automatically resolve it.
You just need this.
function getData() {
return $http(req);
}
I have this in my Angular service:
return $resource(BASE + '/cases/:id',
{id: '#id'}, {
status: {method: 'GET', params: {status: '#status'}}
});
When using the method added to the $resource definition along with the promise's .then() function, I'm getting an error:
Cases.status({status: 'pending'})
.then(function(res) {
console.log(res);
$scope.cases.pending = res.data.cases;
})
.then(function() {
$scope.tabbed.pending = true;
});
After the above snippet is run, the error I get is:
TypeError: undefined is not a function on this line: .then(function(res) {
Can I not use these functions as I usually do when I'm using an extra method defined on the $resource?
I think you need to use $promise of $resource object which will call success function when actual promise gets resolved & then you could proceed with the promise chain.
CODE
Cases.status({status: 'pending'})
.$promise
.then(function(res) {
console.log(res);
$scope.cases.pending = res.data.cases;
})
.then(function(cases) {
$scope.tabbed.pending = true;
});
You have to use $promise in order to access the promise is created on that call, like this:
Cases.get({id: 123}).$promise
.then(function (success) {
//do something
}).then(function (error) {
//do something else
})
Or you can send both functions as callbacks:
Cases.get({id: 123}, function (success) {
//do something
}, function (error) {
//do something else
});
Tip
You don't have to add a new method to that $resource to send a GET to the same url, you can just have your $resource be plain:
//... code
return $resource(BASE + '/cases'});
and when you pass the parameters to it (if you are passing them as in the example) it will match the keys according to the object so you can just say:
Cases.get({status: 'something'}).$promise
.then(function(success){
//... code
})
.then(function(err){
//... code
});
Cases.get({id: 123}).$promise
.then(function(success){
//... code
})
.then(function(err){
//... code
});
I have bug (or maybe wrong usage?) with ui-router, resolve, factory and $http.get call.
Here's a snippet of the code in the config section:
$stateProvider
.state('index', {
url: '/',
views: {
'': {
templateUrl: './views/layout.html',
controller: 'MyAppCtrl'
},
'app-navbar#index': {
templateUrl: './views/app-navbar.html'
},
'app-accordion#index': {
templateUrl: './views/app-accordion.html',
controller: 'AppController',
resolve: {
appPromiseObj: function (AppFactory) {
return AppFactory.getApps();
}
}
},
...
and have the following AppFactory
myApp.factory('AppFactory', function ($http) {
var appFac = {
apps: []
};
appFac.getApps = function () {
promiseObj = $http
.get('http://localhost:4567/applications')
.success(function (data) {
console.log("success calling http");
angular.copy(data, appFac.apps);
});
return promiseObj;
};
return appFac;
});
But when I run the app, the console.log message in the 'success' callback never gets executed. The browser console log shows the http call executes OK with code 200. I am assuming this means angular thinks it has failed or should I be doing something else?
I even tried returning the $q promise object (as suggested in other somewhat related stack overflow threads) but no success. In the factory code if I use test data (i.e., no HTTP call) everything works fine even if I don't return a promise object. Any pointer on where the problem could be? Appreciate any pointers to help me debug...
I created working plunker here. The problem was incorrect promise handling inside of the AppFactory.getApps(). We need to return the promise at the begining and then also return some adjusted stuff on success. Now it works...
This is the main change I made:
// INSTEAD of this
// appFac.getApps1 = function () {
// promiseObj = $http.get('http://localhost:4567/applications')
// .success(function (data) {
// console.log("success calling http");
// angular.copy(data, appFac.apps);
// });
//
// return promiseObj;
// Let's use this
appFac.getApps = function () {
return $http
.get('http://localhost:4567/applications')
.success(function (data) {
console.log("success calling http");
angular.copy(data, appFac.apps);
return appFac.apps
});
// this is already returned above
//return promiseObj;
Check it in action here
EXTEND
Based on your extended plunker (still not fully working as expected)
-http://plnkr.co/edit/c89j3eFvYyguMt0QznAI?p=preview
I created adjsuted and workin version
http://plnkr.co/edit/f2aucPcbtzqwIEogbjuJ?p=preview
The only changes was proper naming (e.g. app.js to be loaded as a script instead of script.js...). But at the end, the promise is now resolved and this json:
[{"id":10566982,"networkID":34256899,"appID":56114114
,"name":"10566982name","description"
...
]
Is loaded and converted into accordion:
56114114name
58616695name
Finally to answer your question in the comment below:
but what is the difference between promiseObj = $http(...)... ; return promiseObj and return $http (...); ?
There is no difference (except I see my approach a bit more clear). The real difference is:
angular.copy(data, appFac.apps);
vs
return appFac.apps
as a final statement of the .success() method. It MUST return something. tha's the trick
I have functions like the getData function below.
I understand that $http returns a promise. In my current set up I am using $q so that I can do some processing of the results and then return another promise:
var getData = function (controller) {
var defer = $q.defer();
$http.get('/api/' + controller + '/GetData')
.success(function (data) {
var dataPlus = [{ id: 0, name: '*' }].concat(data);
defer.resolve({
data: data,
dataPlus: dataPlus
});
})
.error(function (error) {
defer.reject({
data: error
});
});
return defer.promise;
}
Is there any way that I can do this without needing to use the AngularJS $q (or any other $q implementation) or is the code above the only way to do this? Note that I am not looking for a solution where I pass in an onSuccess and an onError to the getData as parameters.
Thanks
As you say $http.get already returns a promise. One of the best things about promises is that they compose nicely. Adding more success, then, or done simply runs them sequentially.
var getData = function (controller) {
return $http.get('/api/' + controller + '/GetData')
.success(function (data) {
var dataPlus = [{ id: 0, name: '*' }].concat(data);
return {
data: data,
dataPlus: dataPlus
};
})
.error(function (error) {
return {
data: error
};
});
}
This means that using getData(controller).then(function (obj) { console.log(obj) });, will print the object returned by your success handler.
If you want you can keep composing it, adding more functionality. Lets say you want to always log results and errors.
var loggingGetData = getData(controller).then(function (obj) {
console.log(obj);
return obj;
}, function (err) {
console.log(err);
return err;
});
You can then use your logging getData like so:
loggingGetData(controller).then(function (obj) {
var data = obj.data;
var dataPlus = obj.dataPlus;
// do stuff with the results from the http request
});
If the $http request resolves, the result will first go through your initial success handler, and then through the logging one, finally ending up in the final function here.
If it does not resolve, it will go through the initial error handler to the error handler defined by loggingGetData and print to console. You could keep adding promises this way and build really advanced stuff.
You can try:
Using an interceptor which provides the response method. However I don't like it, as it moves the code handling the response to another place, making it harder to understand and debug the code.
Using $q would be the best in that case IMO.
Another (better ?) option is locally augmented transformResponse transformer for the $http.get() call, and just return the $http promise.
I'm still new to Angular and promises so I hope I have the correct idea here.
I currently have a data layer service which uses restangular to get some data, then returns a promise, like this...
dataStore.getUsers = function (params) {
return users.getList(params);
};
Then, my controller which has called this function receives a promise back, like this...
$dataStore.getUsers(params).then(function (response) {
$scope.users = response;
}, function(response) {
$log.error("Get users returned an error: ", response);
});
This is working well, but I'd like to use the promise inside of my datastore before passing it back. I'd like to use the .then() method to check if it failed and do some logging, then, from the sucess function and from the failure function I'd like to return the original promise back to my controller.
My controller would then be able to use the .then() method like it already is, in fact, I don't want my controller code to change at all, just my datastore code.
Here's some semi-pseudo code to show what I'd like my datastore function to do...
dataStore.getUsers = function (params) {
users.getList(params).then(function (response) {
$log("server responded")
return original promise;
}, function(response) {
$log.error("server did not respond");
return original promise;
});
};
You were actually not far off at all in your pseudo code. Promises chain:
dataStore.getUsers = function (params) {
return users.getList(params).then(function (response) {
$log("server responded")
return response;
}, function(failure) {
$log.error("server did not respond");
// change to throw if you want Angular lever logs
return $q.reject(failure);
});
};
The controller now gets resolved/rejected with the same value. The log requires tapping into the promise so you must add a .then handler to deal with it. Other promise libraries have convinicene methods for this but $q is minimalistic in this regard.
Alternatively, you can use nicer catch syntax, as well as propagate the errors to your logs:
dataStore.getUsers = function (params) {
return users.getList(params).then(function (response) {
$log("server responded")
return response;
}).catch(function(failure) {
$log.error("server did not respond");
throw failure;
});
};