I have a simple web app based on this project ( https://github.com/arthurkao/angular-drywall ), running with NodeJS and AngularJS as the front-end.
I'm trying to set up a simple page that displays a list of all connected users on a map (using Google Maps, Geolocation and PubNub).
Here's how I'm actually doing it:
angular.module('base').controller('TravelCtrl',
function($rootScope, $scope, NgMap, security, $geolocation, PubNub){
$rootScope.extusers = []; //remote users
$scope.initTravel = function() { //declare the init function
PubNub.init({
subscribe_key: $rootScope.security.keys.psk,
publish_key: $rootScope.security.keys.ppk,
uuid: $rootScope.security.currentUser.username,
ssl: true
});
PubNub.ngSubscribe({
channel: "travel",
state: {
position: {},
}
});
console.log("Loaded Travel");
$geolocation.getCurrentPosition({
timeout: 60000
}).then(function(position) { //when location is retreived
$scope.position = position;
PubNub.ngSubscribe({
channel: "travel",
state: {
position: {
lat: Math.floor($scope.position.coords.latitude*1000)/1000, //decrease accuracy
long: Math.floor($scope.position.coords.longitude*1000)/1000,
},
}
});
$rootScope.$on(PubNub.ngPrsEv("travel"), function(event, payload) {
$scope.$apply(function() {
$scope.extusers = PubNub.ngPresenceData("travel");
});
});
PubNub.ngHereNow({ channel: "travel" });
$scope.showInfo = function(evt, marker) { //show user window on map
$scope.extuser = marker;
$scope.showInfoWindow('infoWindow');
};
});
};
if ($rootScope.hasLoaded()) { //if username and keys are already loaded, then init module
$scope.initTravel();
} else { //else, wait for username and keys to be loaded
$rootScope.$on('info-loaded', function(event, args) {
$scope.initTravel();
});
}
}
);
Although it works, it seems like it's very buggy and only loads sometimes. Occasionally, I get this:
Result screenshot
I really don't know what I'm doing wrong, as I simply followed the tutorials on PubNub's AngularJS SDK.
I think this has to do with how I'm initialising the application.
angular.module('app').run(['$location', '$rootScope', 'security', function($location, $rootScope, security) {
// Get the current user when the application starts
// (in case they are still logged in from a previous session)
$rootScope.hasLoaded = function() {
return (security.keys && security.info && security.currentUser); //check if everything is loaded correctly
};
$rootScope.checkLoading = function() {
if ($rootScope.hasLoaded()) {
$rootScope.$broadcast('info-loaded'); //broadcast event to "TravelCtrl" in order to init the module
}
};
security.requestKeys().then($rootScope.checkLoading); //request secret keys
security.requestSiteInfo().then($rootScope.checkLoading); //then templating info (site title, copyright, etc.)
security.requestCurrentUser().then($rootScope.checkLoading); //and finally, current user (name, id, etc.)
$rootScope.security = security;
// add a listener to $routeChangeSuccess
$rootScope.$on('$routeChangeSuccess', function (event, current, previous) {
$rootScope.title = current.$$route && current.$$route.title? current.$$route.title: 'Default title';
});
}]);
1- Request secret keys, site info and current user with JSON API.
2- Wait until everything's loaded then init the application with the appropriate keys (PubNub, Google Maps)
--
My question is:
How do you instantiate an AngularJS app after retrieving useful information via a RESTful API?
I'm pretty new to AngularJS, and I wouldn't be surprised if my approach is totally ridiculous, but I really need to get some advice on this.
Thanks in advance for your help,
Ulysse
You don't have to wait that the AJAX Query ended to initate the angular APPs.
you can use the $http promise ( details her )
In the controller :
// Simple GET request example:
$http({
method: 'GET',
url: '/someUrl'
}).then(function successCallback(response) {
// this callback will be called asynchronously
// when the response is available
// data is now accessible in the html
$scope.data = response ;
// you can call a function to add markers on your maps with the received data
addMarkerOnMap(response);
}, function errorCallback(response) {
// called asynchronously if an error occurs
// or server returns response with an error status.
});
You can also add a watch on some variable to wait modification on them :
// you should have $scope.yourVarName declared.
$scope.$watch('yourVarName', function(newValue, oldValue) {
console.log(newValue);
});
Or watch a list/object
$scope.$watchCollection('[var1,var2]', function () {
},true);
Related
I am new to IndexedDB and serviceworkers and am having a very difficult time understanding how to turn these into a funcitonal application. I've done extensive reading on both, but even the "complete" examples don't incorporate the two.
I am tasked with creating an application that will allow users to work offline. The first time they connect to the site, I want to pull specific information from the database and store it in IndexedDB. When they go offline, I need to use that data to display information on the page. Certain interactions will cause the data to update, then to be synced later once an internet connection is reestablished. From a high-level, I udnerstand how this works.
It is my understanding that we cannot call functions from the serviceworker.js file due to the asynchronous nature of serviceworkers. Additionally, serviceworkers.js cannot directly update the DOM. However, the examples I have seen are creating and managing the IndexedDB data within the serviceworkers.js file.
So let's say I have a file:
<!-- index.html -->
<html>
<body>
Hello <span id="name"></span>
</body>
</html>
And a serviceworker.js:
var CACHE_NAME = 'my-cache-v1';
var urlsToCache = [
'/'
// More to be added later
];
self.addEventListener('install', function(event) {
// Perform install steps
event.waitUntil(
caches.open(CACHE_NAME)
.then(function(cache) {
console.log('Opened cache');
return cache.addAll(urlsToCache);
})
);
});
self.addEventListener('activate', function(event) {
event.waitUntil(
createDB() //Use this function to create or open the database
);
});
self.addEventListener('fetch', function(event) {
event.respondWith(
caches.match(event.request)
.then(function(response) {
// Cache hit - return response
if (response) {
return response;
}
return fetch(event.request).then(
function(response) {
// Check if we received a valid response
if(!response || response.status !== 200 || response.type !== 'basic') {
return response;
}
var responseToCache = response.clone();
caches.open(CACHE_NAME)
.then(function(cache) {
cache.put(event.request, responseToCache);
});
return response;
}
);
})
);
});
function createDB() {
idb.open('mydata', 1, function(upgradeDB) {
var store = upgradeDB.createObjectStore('user', {
keyPath: 'id'
});
store.put({id: 1, name: 'John Doe'}); //This can be updated with an AJAX call to the database later
});
}
How do I now update the element "name" with the value for key = 1 from the "user" objectstore in the "mydata" database?
Depending on your use case, you've got several options :
You dont need the service worker. Just pull your data from iDB directly from the page. The DOM has access to iDB.
Set a template for your index.html. At the activate step in service worker, pre-render the page with the value from iDB and cache it.
I've been trying to make a request to a NodeJS API. For the client, I am using the Mithril framework. I used their first example to make the request and obtain data:
var Model = {
getAll: function() {
return m.request({method: "GET", url: "http://localhost:3000/store/all"});
}
};
var Component = {
controller: function() {
var stores = Model.getAll();
alert(stores); // The alert box shows exactly this: function (){return arguments.length&&(a=arguments[0]),a}
alert(stores()); // Alert box: undefined
},
view: function(controller) {
...
}
};
After running this I noticed through Chrome Developer Tools that the API is responding correctly with the following:
[{"name":"Mike"},{"name":"Zeza"}]
I can't find a way to obtain this data into the controller. They mentioned that using this method, the var may hold undefined until the request is completed, so I followed the next example by adding:
var stores = m.prop([]);
Before the model and changing the request to:
return m.request({method: "GET", url: "http://localhost:3000/store/all"}).then(stores);
I might be doing something wrong because I get the same result.
The objective is to get the data from the response and send it to the view to iterate.
Explanation:
m.request is a function, m.request.then() too, that is why "store" value is:
"function (){return arguments.length&&(a=arguments[0]),a}"
"stores()" is undefined, because you do an async ajax request, so you cannot get the result immediately, need to wait a bit. If you try to run "stores()" after some delay, your data will be there. That is why you basically need promises("then" feature). Function that is passed as a parameter of "then(param)" is executed when response is ready.
Working sample:
You can start playing with this sample, and implement what you need:
var Model = {
getAll: function() {
return m.request({method: "GET", url: "http://www.w3schools.com/angular/customers.php"});
}
};
var Component = {
controller: function() {
var records = Model.getAll();
return {
records: records
}
},
view: function(ctrl) {
return m("div", [
ctrl.records().records.map(function(record) {
return m("div", record.Name);
})
]);
}
};
m.mount(document.body, Component);
If you have more questions, feel free to ask here.
I have a loginService factory used to perform login, logout and provide user data to controllers. Because I need to update userdata in controllers every time loginstate changes, my factory method is returning an update promise:
app.controller('TestCtrl', function ($scope, loginService) {
loginService.currentUserData().then(null, null, function(CurrUserData){
$scope.CurrUserData = CurrUserData;
});
});
In loginService I'm listening to $firebaseSimpleLogin:login/logout events and after they're fired, I pass the userdata object (returned by function based on UID) or null ($fbSimpleLogin:logout event) to $emit.
And finally, in my loginService.currentUserData() method I'm listening to this emitted events and returning deferred.notify(userdata/null).
First issue is that when I change the view (template+ctrl+location), I need to invoke $firebaseSimpleLogin:login/logout event to deliver my userData to new controller. Now, I'm doing it by $locationChangeStart event, but there should be better way...
And last issue: when I'm changing the view, there are more data calls, than I expectet.
Probably every controller add event listeners on $rootScope by calling loginService.currentUserData()? Described code below:
$rootScope.$on('$firebaseSimpleLogin:login', function (e, authUser) {
findUserByUid(authUser.uid);
});
$rootScope.$on('$firebaseSimpleLogin:logout', function() {
$rootScope.$emit('userLogout', null);
});
$rootScope.$on('$locationChangeStart', function(event, next, current) {
currentUser().then(function(u){
$timeout(function() { // without this same event on viewchange is fired
// by simplelogin, collision (I need to replace this whole block with invoking simpleloginevent)
if (u) {$rootScope.$emit('$firebaseSimpleLogin:login', u);
} else {$rootScope.$emit('$firebaseSimpleLogin:logout', null);};
}, 150);
});
});
function findUserByUid (uid) {
var query = $firebase(usersRef.startAt(uid).endAt(uid));
query.$on('loaded', function () {
var username = query.$getIndex()[0];
setCurrentUser(username);
});
}
function setCurrentUser (username) {
if (username) {$rootScope.$emit('userData', $firebase(usersRef).$child(username));};
}
var currentUserData = function () { // this method is used in CTRLs
var deferred = $q.defer();
var uDl = $rootScope.$on('userData', function(e, FbUserData){deferred.notify(FbUserData); });
var uLl = $rootScope.$on('userLogout', function(){deferred.notify(null); });
return deferred.promise;
};
I recently wrote a demo AngularFire app that has similar functionality. The way I found to handle this is only worry about three points.
When the user logs in $rootScope.$on('$firebaseSimpleLogin:$login')
When the user logs out $rootScope.$on('$firebaseSimpleLogin:$logout')
Calling $getCurrentUser()
This will be able to capture the login life cycle. Since you need to know who the current user is, you can rely on the $firebaseSimpleLogin method rather than trying to $emit your own events.
You also could resolve the current user in the $routeProvider for each view. This way each view won't be rendered until the user has been loaded.
Here's the plunker project and the example Factory:
http://plnkr.co/edit/M0UJmm?p=preview
// Auth factory that encapsulates $firebaseSimpleLogin methods
// provides easy use of capturing events that were emitted
// on the $rootScope when users login and out
.factory('Auth', function($firebaseSimpleLogin, Fb, $rootScope) {
var simpleLogin = $firebaseSimpleLogin(Fb);
return {
getCurrentUser: function() {
return simpleLogin.$getCurrentUser();
},
login: function(provider, user) {
simpleLogin.$login(provider, {
email: user.email,
password: user.password
});
},
logout: function() {
simpleLogin.$logout();
},
onLogin: function(cb) {
$rootScope.$on('$firebaseSimpleLogin:login',
function(e, user) {
cb(e, user);
});
},
onLogout: function(cb) {
$rootScope.$on('$firebaseSimpleLogin:logout',
function(e, user) {
cb(e, user);
});
}
}
})
I have a problem with my angular app- after a user signs in, if he hits the refresh button, the signin info is lost and the app redirects to the log in page. I found a SO answer for something similar here using $cookieStore but I don't think it can work for me as I'm not using cookies. Can anyone suggest a solution? Here's my authorization service-
var app = angular.module('myApp.services');
app.factory('SignIn', ['$resource', '$q', function($resource, $q) {
var signInUrl = 'https://example.com'
var API = $resource(signInUrl, {}, {
signIn: {
withCredentials: true,
url: signInUrl + '/session',
method: 'POST'
},
signOut: {
url: authApiUrl + '/session',
method: 'DELETE'
},
currentUser: {
url: signInUrl + '/users/#me',
method: 'GET'
}
});
var _currentUser = undefined;
return {
isAuthenticated: function() {
return !!_currentUser;
},
getUser: function(){
var d = $q.defer();
// If _currentUser is undefined then we should get current user
if (_currentUser === undefined) {
API.currentUser(function(userData) {
_currentUser = userData;
d.resolve(userData);
}, function(response) {
if (response.statusCode === 401) {
_currentUser = null;
d.resolve(_currentUser);
} else {
d.reject(response);
}
});
} else {
d.resolve(_currentUser);
}
return d.promise;
},
signIn: function(username, password){
var d = $q.defer();
API.signIn({email: username, password: password}, function(data, headers){
_currentUser = data;
d.resolve(_currentUser);
}, d.reject);
return d.promise;
},
signOut: function(){
var d = $q.defer();
API.signOut(function(){
_currentUser = null;
d.resolve();
}, d.reject);
return d.promise;
}
};
}]);
If you just need to keep track of the _currentUser data past a refresh then you could use sessionStorage within the browser. That extends all the way back to IE 8 and we really shouldn't be supporting any browsers before that anyway.
Usually these things are done with cookies though. When the client first makes a connection to the server (even before the first API call in some cases) a cookie is sent to the client so the server can maintain a session associated with that particular client. That's because the cookie is automatically sent back to the server with each request and the server can check its local session and say, "Oh, I'm talking to this user. Now I can use that additional piece of context to know if I can satisfy their API call or not."
You don't show any of your other API calls here but I'm guessing that you're sending something out of the _currentUser with each API call to identify the user instead? If so, that certainly works, and it avoids the need to synchronize cookies across multiple servers if you're clustering servers, but you're going to have to use something local like sessionStorage or localStorage that won't get dumped like your current in-memory copy of the data does when you refresh the page.
Maybe I'm going about this the wrong way, i'm not sure, but I have 2 services, one is a user service which gets a bunch of details about the user from the server, the other being one that relies on some user details from the user service and then makes some more calls to the server to get other information.
Anyway, because of the async stuff that goes on when the 2nd service makes the calls the information required from the user server has not yet been populated.
I know Angular services can depend on one another, but not in this context it would appear?
factory('User', ['$resource', function ($resource) {
return $resource(usersUrl, {}, {
//The data model is loaded via a GET request to the app
query: {method: 'GET', params: {}, isArray: false},
putupdate: {method: 'PUT', params:{}}
});
}])
.factory('UserData', function() {
var data = {}
data.userinfo = {};
if(data = {}){
}
return {
updateinfo: function(newdata) {
data.userinfo = newdata;
// alert(data.userinfo.user)
},
userinfo: data
}
})
.factory('PlansData', ['UserData', 'User', '$rootScope', function(userData, user, $rootScope) {
var data = {}
data.plansinfo = {};
//alert(userData.data.userinfo.user.email)
if(data = {}){
}
return {
updateinfo: function(newdata) {
alert(user.query())
data.plansinfo = newdata;
},
plansinfo: data
}
}])
So I have a user service and a caching userdata service, but if I ever try and call anything from UserData in the PlansData service I get undefined.
How do I get plansData to wait for UserData to have some data?
Thanks
Tom
I'm not sure what you're trying to accomplish, but this line of code:
if(data = {}){
}
In both your services is wiping out your data object. You're setting the whole data object to be {}