angularJS $timeout function used and page reloading on service calls - angularjs

I have used $timeout to call an angular JS service in every 5 seconds. But it leads to a page or cursor reload in my application. Can anyone assist me to stop the page reload?
var app = angular.module('myApp', ['ngAnimate']);
app.controller('MainCtrl', function($scope, $http, $timeout) {
var loadTime = 1000, //Load the data every second
errorCount = 0, //Counter for the server errors
loadPromise; //Pointer to the promise created by the Angular $timout service
var getData = function() {
//console.log('http://httpbin.org/delay/1?now=' + Date.now());
$http.get('http://httpbin.org/delay/1?now=' + Date.now())
.then(function(res) {
$scope.data = res.data.args;
errorCount = 0;
nextLoad();
})
.catch(function(res) {
$scope.data = 'Server error';
nextLoad(++errorCount * 2 * loadTime);
});
};
var cancelNextLoad = function() {
$timeout.cancel(loadPromise);
};
var nextLoad = function(mill) {
mill = mill || loadTime;
//Always make sure the last timeout is cleared before starting a new one
cancelNextLoad();
loadPromise = $timeout(getData, mill);
};
//Start polling the data from the server
getData();
//Always clear the timeout when the view is destroyed, otherwise it will keep polling and leak memory
$scope.$on('$destroy', function() {
cancelNextLoad();
});
$scope.data = 'Loading...';
});

Check to make sure loadPromise exists before cancelling it:
var cancelNextLoad = function() {
̶$̶t̶i̶m̶e̶o̶u̶t̶.̶c̶a̶n̶c̶e̶l̶(̶l̶o̶a̶d̶P̶r̶o̶m̶i̶s̶e̶)̶;̶
loadPromise && $timeout.cancel(loadPromise);
};

Related

Is there a way to find the pendingReuests in new angular apps

I'm trying to automate an angular app using selenium. Before running the selenium script I would want to wait for the app to completely load. I used the following code to do this, but after the app was updated to a new angular version, I'm not able to get the pending requests using this method.
I tried searching for a solution for a few days, but couldn't find any. Thanks in advance :)
angular.element(document).injector().get('$http').pendingRequests.length.toString();
In the latest Angular, you can access Pending Requests from the built-in HTTP$ directly
Or if you want to wrap it in a service look ref from here/below
angular.module('app', [])
// This service keeps track of pending requests
.service('pendingRequests', function() {
var pending = [];
this.get = function() {
return pending;
};
this.add = function(request) {
pending.push(request);
};
this.remove = function(request) {
pending = _.filter(pending, function(p) {
return p.url !== request;
});
};
this.cancelAll = function() {
angular.forEach(pending, function(p) {
p.canceller.resolve();
});
pending.length = 0;
};
})
// This service wraps $http to make sure pending requests are tracked
.service('httpService', ['$http', '$q', 'pendingRequests', function($http, $q, pendingRequests) {
this.get = function(url) {
var canceller = $q.defer();
pendingRequests.add({
url: url,
canceller: canceller
});
//Request gets cancelled if the timeout-promise is resolved
var requestPromise = $http.get(url, { timeout: canceller.promise });
//Once a request has failed or succeeded, remove it from the pending list
requestPromise.finally(function() {
pendingRequests.remove(url);
});
return requestPromise;
}
}])

Angular two way binding not working

I'm very new to angularjs and I want to establish a connection to my server and dynamically show the result to user. so far I've tried:
angular.module('myApp.controllers', []).controller('socketsController', function($scope) {
$scope.socket = {
client: null,
stomp: null
};
$scope.reconnect = function() {
setTimeout($scope.initSockets, 10000);
};
$scope.notify = function(message) {
$scope.result = message.body;
};
$scope.initSockets = function() {
$scope.socket.client = new SockJS('/resources');
$scope.socket.stomp = Stomp.over($scope.socket.client);
$scope.socket.stomp.connect({}, function() {
$scope.socket.stomp.subscribe('/user/topic/messages', $scope.notify);
});
$scope.socket.client.onclose = $scope.reconnect;
};
$scope.initSockets();
});
But when I use {{result}} nothing appears.
UPDATE
The server response is totally right with console.log(message.body).
I guess, the callback is not taking the scope properly. Try call $scope.$apply(); after you attach the message.body to result :
$scope.notify = function(message) {
$scope.result = message.body;
$scope.$apply();
};
$scope.$apply() triggers an angular digest cycle whcih will update all the bindings..
Call it inside a timeout function but inject $timeout first it will call the digest cycle and update the value.
$timeout(function(){
$scope.result = message.body;});

Angular - Wait for .Run finish all the pending async requests

My app had this .run
.run(function ($rootScope, $http) {
$rootScope.server = "http://127.0.0.1:5000/rawDemo";
var call = $rootScope.server + "/frontEnd/GetStructure";
var texts = {};
texts.languages = {};
$http.get(call).then(function (response) {
for (var i = 0; i < response.data.languages.length; i++) {
texts.languages[response.data.languages[i].iso2] = {
'title': response.data.languages[i].title,
'description': response.data.languages[i].description,
'keywords': response.data.languages[i].keywords,
'frontEndTexts': response.data.languages[i].frontEndTexts
};
}
$rootScope.texts = texts;
$rootScope.webshop = response.data;
$rootScope.webshop.language = response.data.culture.language;
$rootScope.webshop.numberFormat = "";
$rootScope.carouselData = response.data.frontEndConfig.customConfiguration.mjCarousel;
console.log('end run');
});
})
.And some of my resolvers perform a call in a service...
angular
.module('app')
.factory('Products',['$http', '$rootScope', function($http, $rootScope){
return {
listByCategories : function (categories){
console.log('begin service');
var call = $rootScope.server + '/products/list/categories/' + categories.fullPath +'?page1&recordsPerPage=2' ;
return $http.get(call).then(function(response) {
return response.data;
});
}
}
}])
My expected result in console.log supposed to be:
- end run
- begin service
but instead..begin service starts before the end run. It's because the .run finish and keep the $http executing asynchronously and go on to the next stages like resolvers, for example.
According to my research on this website, it's impossible to make the $http works synchronous. So, my question is...any hint about how to handle the scenario ? My service depends from data that's must be loaded before anything.
I cannot "merge" the .run and the service because all the others views, services, must have the .run executed before. in my .run I load dozen of global configurations basically.
UPDATE : I'm still stucked...but I'm trying something...I changed the way I'm doing the things..
so, on my .run
$rootScope.loadWebshop = function(callBack) {
if($rootScope.loaded) { return ; }
var call = $rootScope.server + "/frontEnd/GetStructure";
var texts = {};
texts.languages = {};
$http.get(call).then(function (response) {
for (var i = 0; i < response.data.languages.length; i++) {
texts.languages[response.data.languages[i].iso2] = {
'title': response.data.languages[i].title,
'description': response.data.languages[i].description,
'keywords': response.data.languages[i].keywords,
'frontEndTexts': response.data.languages[i].frontEndTexts
};
}
$rootScope.texts = texts;
$rootScope.webshop = response.data;
$rootScope.webshop.language = response.data.culture.language;
$rootScope.webshop.numberFormat = "";
$rootScope.carouselData = response.data.frontEndConfig.customConfiguration.mjCarousel;
$rootScope.loaded = true;
console.log('end .run');
callBack();
});
}
..And on my service :
listByCategories : function (categories){
return $rootScope.loadWebshop (function () {
console.log('begin service');
var call = $rootScope.server + '/products/list/categories/' + categories.fullPath +'?page1&recordsPerPage=2' ;
return $http.get(call).then(function(response) {
return response.data;
});
});
}
Now I'm facing a different issue...it's returns undefined because it's asyncronous, even using premise. Any clue ??

How to integrate an AngularJS service with the digest loop

I'm trying to write an AngularJS library for Pusher (http://pusher.com) and have run into some problems with my understanding of the digest loop and how it works. I am writing what is essentially an Angular wrapper on top of the Pusher javascript library.
The problem I'm facing is that when a Pusher event is triggered and my app is subscribed to it, it receives the message but doesn't update the scope where the subscription was setup.
I have the following code at the moment:
angular.module('pusher-angular', [])
.provider('PusherService', function () {
var apiKey = '';
var initOptions = {};
this.setOptions = function (options) {
initOptions = options || initOptions;
return this;
};
this.setToken = function (token) {
apiKey = token || apiKey;
return this;
};
this.$get = ['$window',
function ($window) {
var pusher = new $window.Pusher(apiKey, initOptions);
return pusher;
}];
})
.factory('Pusher', ['$rootScope', '$q', 'PusherService', 'PusherEventsService',
function ($rootScope, $q, PusherService, PusherEventsService) {
var client = PusherService;
return {
subscribe: function (channelName) {
return client.subscribe(channelName);
}
}
}
]);
.controller('ItemListController', ['$scope', 'Pusher', function($scope, Pusher) {
$scope.items = [];
var channel = Pusher.subscribe('items')
channel.bind('new', function(item) {
console.log(item);
$scope.items.push(item);
})
}]);
and in another file that sets the app up:
angular.module('myApp', [
'pusher-angular'
]).
config(['PusherServiceProvider',
function(PusherServiceProvider) {
PusherServiceProvider
.setToken('API KEY')
.setOptions({});
}
]);
I've removed some of the code to make it more concise.
In the ItemListController the $scope.items variable doesn't update when a message is received from Pusher.
My question is how can I make it such that when a message is received from Pusher that it then triggers a digest such that the scope updates and the changes are reflected in the DOM?
Edit: I know that I can just wrap the subscribe callback in a $scope.$apply(), but I don't want to have to do that for every callback. Is there a way that I can integrate it with the service?
On the controller level:
Angular doesn't know about the channel.bind event, so you have to kick off the cycle yourself.
All you have to do is call $scope.$digest() after the $scope.items gets updated.
.controller('ItemListController', ['$scope', 'Pusher', function($scope, Pusher) {
$scope.items = [];
var channel = Pusher.subscribe('items')
channel.bind('new', function(item) {
console.log(item);
$scope.items.push(item);
$scope.$digest(); // <-- this should be all you need
})
Pusher Decorator Alternative:
.provider('PusherService', function () {
var apiKey = '';
var initOptions = {};
this.setOptions = function (options) {
initOptions = options || initOptions;
return this;
};
this.setToken = function (token) {
apiKey = token || apiKey;
return this;
};
this.$get = ['$window','$rootScope',
function ($window, $rootScope) {
var pusher = new $window.Pusher(apiKey, initOptions),
oldTrigger = pusher.trigger; // <-- save off the old pusher.trigger
pusher.trigger = function decoratedTrigger() {
// here we redefine the pusher.trigger to:
// 1. run the old trigger and save off the result
var result = oldTrigger.apply(pusher, arguments);
// 2. kick off the $digest cycle
$rootScope.$digest();
// 3. return the result from the the original pusher.trigger
return result;
};
return pusher;
}];
I found that I can do something like this and it works:
bind: function (eventName, callback) {
client.bind(eventName, function () {
callback.call(this, arguments[0]);
$rootScope.$apply();
});
},
channelBind: function (channelName, eventName, callback) {
var channel = client.channel(channelName);
channel.bind(eventName, function() {
callback.call(this, arguments[0]);
$rootScope.$apply();
})
},
I'm not really happy with this though, and it feels as though there must be something bigger than I'm missing that would make this better.

AngularJS : remove $rootScope from a service

I have a service wrapped around WebSocket, I wanted to do it with promises and coupling requests with responses, here is what I came up with:
(function () {
var app = angular.module('mainModule');
app.service('$wsService', ['$q', '$rootScope', '$window', function($q, $rootScope, $window) {
var self = this;
// Keep all pending requests here until they get responses
var callbacks = {};
// Create a unique callback ID to map requests to responses
var currentCallbackId = 0;
var ws = new WebSocket("ws://127.0.0.1:9090");
this.webSocket = ws;
ws.onopen = function(){
$window.console.log("WS SERVICE: connected");
};
ws.onmessage = function(message) {
listener(JSON.parse(message.data));
};
var listener = function (messageObj) {
// If an object exists with callback_id in our callbacks object, resolve it
if(callbacks.hasOwnProperty(messageObj.Request.ID)) {
$rootScope.$apply(
callbacks[messageObj.Request.ID].cb.resolve(messageObj));
delete callbacks[messageObj.Request.ID];
}
};
// This creates a new callback ID for a request
var getCallbackId = function () {
currentCallbackId += 1;
if(currentCallbackId > 10000) {
currentCallbackId = 0;
}
return currentCallbackId;
};
//sends a request
var sendRequest = function (request, callback) {
var defer = $q.defer();
var callbackId = getCallbackId();
callbacks[callbackId] = {
time: new Date(),
cb:defer
};
request.ID = callbackId;
$window.console.log("WS SERVICE: sending " + JSON.stringify(request));
ws.send(JSON.stringify(request));
if(typeof callback === 'function') {
defer.promise.then(function(data) {
callback(null, data);
},
function(error) {
callback(error, null);
});
}
return defer.promise;
};
this.exampleCommand = function(someObject, callback){
var promise = sendRequest(someObject, callback);
return promise;
};
}]);
}());
And I use it in a controller like so:
(function () {
'use strict';
var app = angular.module('mainModule');
app.controller('someController', ['$scope', '$wsService', function ($scope, $wsService) {
$scope.doSomething = function(){
$wsService.exampleCommand(
{/*some data for the request here*/},
function(error, message){
//do something with the response
}
);
};
}]);
}());
After implementing this, I have been told that the service should not really operate on any kind of scope. So my question is - how would I go about removing the $rootScope from the service? I am not even sure if I should get rid of it, and if the conventions say I should, how to approach it. Thanks
I have been told that the service should not really operate on any kind of scope.
Who told you that? It's completely wrong.
Your service is receiving callbacks outside of a digest cycle from the websocket. To work with angular, those updates need to be applied inside a digest cycle - this is exactly what you're doing.
For reference, see the built in $http service. That wraps XMLHttpRequest analogously to how you're wrapping web sockets and it depends on $rootScope for exactly the functionality your code depends on $rootScope for.
Your code demonstrates the canonical use of $rootScope inside a service.

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