I use AngularJS on the client side to display some informations that'll get pushed through a NodeJS-Server. The data will be held in a service factory.
I want to watch this data through the angular watch function.
The problem i run into, is the following. watch runs through the factory only once and stops.
And if the server pushes changed data it won't update the view?
Here is some code snippet.
.factory('clientStorage', ['socket', function (socket){
var that = {};
//basis data
that.basisData = {};
that.getBasisData = function () {
socket.on('sendBasis', function (basis) {
console.log('ich hoffe doch');
that.basisData = basis;
console.log(that.basisData);
});
console.log(that.basisData);
return that.basisData;
};
return that;
}]);
I don't know why this happens?
Anybody there who may help?
Greetings
Henrik
Try this in your controller:
$scope.$watch( function() { return clientStorage.basisData; }, function(clientData) {
$scope.data = clientData;
});
Where $scope.data is the data you are trying to update.
Related
What i am doing is; i get the data from db and put it in
$scope.GetMyData = function () {
//http get request here
.then(function (result) {
$scope.myData = result.data;
});
}
and when i want to refresh
$scope.myData
I have a function which is ticking every 15 seconds to trigger my GetMyData function to get the updated data. The timer function is like;
$interval(function () {
$scope.GetMyData();
}, 15000);
The problem is whenever I've overwritten $scope.myData, Page is not actually refreshing but the view looks like it's refreshed. Is there a way to solve this ?
Use $watch service helps you to run some code when some value attached to the $scope has changed.
$scope.myData = "";
$scope.$watch('myData', function() {
/*Here you can bind changed value to your view, updated value can be reflected on $scope.myData change */
alert('myData has changed!');
});
I'm trying to retrieve a list of data from mysql database by using electron and bind it to a list in the controllers scope. I'm using mysql2. Here is my controller:
$scope.carList = [];
mysql.execute("SELECT * FROM cars").spread(function(results){
$scope.carList = results;
console.log(results);
})
I do get the results back, but the in the view carList remains empty. How can I solve this problem?
I just added a button to my view and bound it to a check function like this:
$scope.check = function(){
console.log($scope.carList);
}
After I click on the button, my list in the views gets populated. Now my question would be how can I have my list populated on the start of the controller rather than wait for an event ro make it happen?
I think mysql.execute("").spread(fn) promise is not a part of the AngularJS digest cycle. You did not provide enough code to fully reproduce your problem but I think by triggering a new digest cycle it should work for you. E.g. try it with $timeout which triggers a new digest cycle.
$scope.carList = [];
mysql.execute("SELECT * FROM cars").spread(function(results){
$timeout(function () {
$scope.carList = results;
});
})
I would prefer to create a AngularJS service which handles your electron mysql in a nice way. You could globally apply your $scopes in it, right after finishing your mysql procedures which are not a part of your digest cycle.
Approach by using AngularJS promises
var myApp = angular.module('myApp', []);
myApp.controller('MyCtrl', function($scope, $q) {
$scope.carList = [];
getCars.then(function(cars) {
$scope.carList = cars;
});
function getCars() {
var deferred = $q.defer();
mysql.execute("SELECT * FROM cars").spread(function(results) {
deferred.resolve(results);
});
return deferred.promise;
}
});
I've been facing a trouble while working with Factory/Service. I've created an AjaxRequests factory for all of my AJAX calls. My factory code is
.factory('AjaxRequests', ['$http', function ($http) {
return {
getCampaignsData: function () {
var campaigns
return $http.get(url).then(function (response) {
campaigns = response.data;
return campaigns;
});
}
}
}])
I've created another service in which I am injecting this factory. My service code
.service('CampaignsService', ['$rootScope', 'AjaxRequests', function ($rootScope, AjaxRequests) {
this.init = function () {
this.camps;
AjaxRequests.getCampaignsData().then(function (response) {
this.camps = response.campaigns;
console.log(this.camps); // It is showing data
})
console.log(this.camps); // But it is not working :(
};
this.init();
}])
And in my controller
.controller('AdvanceSettingsController', ['$scope', 'CampaignsService', function ($scope, CampaignsService) {
$scope.CampaignsService = CampaignsService;
}
])
I've read this article to learn promises but it is not working here. I can directly achieve it in controller and it's been working fine. But it consider as a bad coding standard to make controller thick. But when I use service and factory I stuck. My question is why I am not getting ajax data to use in my whole service ? I need to use CampaignsService.camps in my view template as well as in my whole rest script but every time I get undefined. What is happening here? I've asked the same question before but couldn't get any success. Some one please help me to understand about promises and why I am getting this type of error if I'm working same ? This type of question has already been asked before but it was working in controller. May be I am stuck because I'm using it in a service.
A big thanks in advance.
This is not a bug or some tricky functionality. Just like in any other AJAX implementation, you can only access the response data in AngularJS's $http success method. That's because of the asynchronous nature of Asynchronous JavaScript And XML.
And what you have is working.
.controller('AdvanceSettingsController', ['$scope', 'AjaxRequests', function ($scope, AjaxRequests) {
$scope.camps = [];
AjaxRequests.getCampaignsData().then(function(data) {
$scope.camps = data;
});
}
])
And then bind camps:
<div ng-repeat="camp in camps>{{camp.name}}</div>
What's bad in your implementation is that instead of grouping related stuff in services you are writing a big AjaxRequests service for everything. You should have a CampaignsService that has a getData method and inject that in your controller.
Why is this working? Because $http does a $scope.$apply for you, which triggers a digest cycle after the data is loaded (then) and updates the HTML. So before the then callback that ng-repeat is run with [] and after it it's again run but with data from the response because you are setting $scope.camps = data;.
The reason <div ng-repeat="camp in CampaignsService.camps>{{camp.name}}</div> does not work is because of function variable scoping.
The this reference inside of your then callback is not the same as the this reference outside of it.
This will work and uses the common var self = this trick:
var self = this;
this.camps = [];
this.init = function () {
AjaxRequests.getCampaignsData().then(function (response) {
// here "this" is not the one from outside.
// "self" on the other hand is!
self.camps = response.campaigns;
});
};
I have a service with the following:
.service('TasksService', function ($http) {
return $http.jsonp('http://blabla/json/?callback=JSON_CALLBACK');
});
My controller:
.controller("TasksCtrl", function ($scope, TasksService) {
TasksService.then(function (TasksService) {
$scope.Tasks = TasksService;
});
});
This shows list with many items.
But I have another service and another controller. I change an item there and when I save and post data to database and I get back to initial list, I still see the old listed items. I must refresh the browser to see what I have edited.
In the second controller I have save function with this:
$scope.saveTask = function () {
$http.post('http://blabla', $scope.Task.data).then(function (data) {
// This shows the very first state with all the listed items
$state.go('tasks');
});
};
When I save the changes and state.go() shows me the first screen I do not know why the data is not with the new changes from the service returned data. It seems like the screen is just changed but the new data is not returned from the service. Any ideas how to fix this?
I got it working. I changed my service and controller. In my service I returned an object with another method and then I changed my controller also to use the returned method.
The service:
.service('TasksService', function ($http) {
return {
getTasks: function() {
return $http.jsonp('http://blabla/json/?callback=JSON_CALLBACK');
}
};
});
And the controller:
.controller("TasksCtrl", function ($scope, TasksService) {
TasksService.getTasks().then(function (data) {
$scope.Tasks = data;
});
});
Now it is working and I see the items list the new saved and returned data. Thank you!
All you need is to reflect the changed data into your html
Angular has a method for this
$scope.$apply();
This method works both with parameters as well as without parameters.
Hope this helps.
I asked the wrong question yesterday (and got a goodanswer that worked), but am realizing it's not what I needed. I need to be able to retrieve JSON data (preferably once), store it, and access it throughout my service. The challenge I'm having is that all the examples I can find talk about using JSON and passing to the app/controller, whereas in this case I need to get it, check it, and then it dictates what my module/service does.
For instance, I have my App and Controller, and then I have a module such as (this is psuedo-code, not meant to run):
angular.module("myModule")
.service("myService1", function($q, myService2, $http) {
this.getModel = function() {
return {
title: "My Title",
desc: "My Desc"
options: function () {
if (condition A)
return "option1";
else
return "option2";
}
};
};
})
.service("myService2", function($q, $http) {
this.getCfgInfo = function () {
var defer = $q.defer();
$http.get("my/json/url").then(function(response) {
defer.resolve(response.data);
});
return defer.promise;
};
})
In this example, I'm wanting to get the JSON, and use it within myService1 for both literal values (title, desc) as well as for conditions (condition A within the if).
I know I can do something like this (thanks to Joel for helping yesterday):
service("myService1", function($q, myService2, $http) {
// get a promise object for the configuration info
var cfgProm = rtDataMapper.getCfgInfo()
this.getModel = function() {
return {
title: cfgProm.then(function(response) {
return response.JSON_NAME;
}),
and it works fine as I've got the title mapped back into my model and there is a watch(), but I'm stumped as to how I get, store, and use the JSON within the service itself as a conditional (i.e. if (condition A) where condition A is coming from the JSON. Trying to wrap these in .then() doesn't seem to make sense, or at least I can't figure out how to do it.
I'm new to Angular and am attempting to modify some code that was left to us. I'm guessing I don't need the myService2 just to get the JSON. Can anyone help point me in the right direction? I've spent several hours online but can't seem to find a relevant reference/example.
Thanks
Live demo (click).
I'm having the service immediately get the data when it is injected (that code will only run once no matter how many times you inject it). That's nice because you won't have to call a function to get the data - it's called for when creating the service.
Your service method that returns that data will need to return the promise of the data, of course, since you aren't guaranteed that it will have come through when you ask for it. You can pass arguments to that method to use to determine your conditions. All you need to do for that is use promise.then in the method and resolve the promise with the modified data. Since that method is returning the promise already, the modification will be updated on the resolve. See all of this below and in the demo.
var app = angular.module('myApp', []);
app.controller('myCtrl', function($scope, myService) {
myService.getData(15).then(function(data) {
$scope.myData = data;
});
});
app.factory('myService', function($q, $timeout) {
//this code only runs once when you first inject the service
//get data immediately
var deferred = $q.defer();
$timeout(function() { //simulate ajax call
var data = { //ajax response data
foo: 15,
bar: 'Some data!'
};
data = modifyData(data, 1);
deferred.resolve(data);
}, 500);
function modifyData(data, fooVal) {
if (data.foo === fooVal) {
data.baz = 'Conditional data!';
}
return data;
}
var myService = {
//data can be modified when it comes from the server,
//or any time you call this function
getData: function(fooVal) {
if (fooVal) { //if you want to modify the data
deferred.promise.then(function(data) {
data = modifyData(data, fooVal);
deferred.resolve(data);
});
}
return deferred.promise;
}
};
return myService;
});