I'm using angularJS
to build a simple single page application using AJAX, but I'm running into a problem when users use the native back button.
angular.module('myApp', ['ionic', 'myApp.controllers', myApp.services])
.config(function ($routeProvider, $locationProvider) {
$routeProvider.when('/home', {
templateUrl: 'templates/feed.html',
controller: 'MenuCtrl',
reloadOnSearch: false
});
$routeProvider.when('/checkin/view/:id', {
templateUrl: 'templates/checkin.html',
controller: 'MenuCtrl'
});
$routeProvider.otherwise({
redirectTo: '/home'
});
$locationProvider.html5Mode(true)
})
UPDATE: moved $http out of controls per feedback, and suggestions:
And my services.js
file:
angular.module('myApp.services', [])
.factory('FeedService', ['$http', function($http){
var state = {};
var loadFeed = function(){
$http({
method: 'GET',
url: 'http://api.example',
}).success(function(data){
// With the data succesfully returned, call our callback
state = data.response;
console.log(data);
}).error(function(){
alert("error");
});
};
loadFeed();
return {
getState: function(scope){
return state;
}
};
}])
And my controller.js
file:
angular.module('myApp.controllers', [])
.controller('MenuCtrl', function($scope, $http, $location, FeedService) {
// feedback per second answer
$scope.items = FeedService.getState();
})
.controller('CheckinCtrl', function($scope, $routeParams) {
$scope.checkin_id = $routeParams.id;
console.log($routeParams.id);
});
My main index.html
is setup like this:
<body ng-app="untappd">
<div ng-view></div>
</body>
This works great from navigation from a feed (/home)
, to a check-in page (/checkin/view/:id)
but, once the user hits the native back button on the browser or using window.history.back()
, code in the controller
is called again, which makes the AJAX call to pull down the user's friend feed. Should I be using ng-show
instead of using ng-view
for this use case, and create individual "pages" for each content I want to show? I was concerned with the performance, but it appears that I can't get data to persist in each ng-view
without it having to re-call the templates. Any guidance here?
UPDATE: I have changed this to incorporate the Best Practices, by adding the $http
request at the services
level, instead of the controller
level. I still run in to the issue of the getState request being fired, before the the AJAX of the $http
is complete, thus having an empty state, and nothing to render the $scope
.
Yep, the Back button and the the Refresh button are a real pain. You have two choices:
You keep things simple and just allow your state to be fetched for each location change. This treats a user triggered back button click or a refresh as any normal location change. Data re-fetching can be mitigated by http caching.
You maintain your own state on the client and restore it when required, possibly using
SessionStorage
to keep things clean.I chose the latter option and it all works just fine for me. See these self answered questions for detailed code examples.
Use a service to keep a singleton state, which exposes functions to get/reload/etc. Here is a very simple example, just to get you started:
Again, this is very basic, and is simply showing you how you can use a service to store a persistent state between routes.
if your parameter 'id' in the route contains any character that is being decoded during the http request (like ' ' => '%20') then your route will not work. try to perform encodeURIComponent() on your string before using it for the routing.