Angular - How can I clear factory variables when the view changes? - angularjs

I'm fairly new to angular, so bear with me. :-)
I have a list of contacts in one view. I put together a service with some setter and getter functions to hold the contact ID. When the user clicks a contact on the list view, it sets the ID in the service and moves to the edit form view. This is working well, but when I'm done editing and click to go back to the list view I want to clear the variables in the service. How would I do that?
I found one other answer on this topic, but I think it's using the built in angular router instead of ui-router.
Angular updating and clearing factory variables
Also, wouldn't the method in that answer also clear the variables when the user moved from the list to the edit form in the first place?
Thanks!

If it's a route change you can use $locationChangeStart, see $location
For example in your edit controller, register for the event on route change:
var onloc = $scope.$on('$locationChangeStart', function (event, newUrl, oldUrl) {
myService.cleanUp(whatever);
onloc();
});

Related

Prevent Firebase $firebaseArray auto update

I am working on a News Feed that is similar to Facebook News Feed. I am implementing it in the following sequence:
When app is started, get everything, but only push two item to show.
The user can scroll down to see more and I will add more to the list.
If there are any new items, the user needs to pull to refresh to add the new ones.
The only problem I have right now is that each time an item is added, $firebaseArray automatically adds the new item to my array that I do not want snyc changes (I want to query once, get a set list). I was wondering if anyone would know how to prevent the auto update?
Look into .once this will allow you to get the data just once: https://firebase.google.com/docs/reference/js/firebase.database.Query#once
Instead of binding directly your $firebaseArray to the view, clone it to a scope (or controller) property that will be bound to the view. Factorize this process in a function you can call when the user pull-reloads so the the $firebaseArray is re-created.
A more appropriate approach would be to use Firebase's http api, with the angular $http service.
Edit: to clone the array to a scope var, try the following:
var allEvents = $firebaseArray(queryOfeverything);
allEvents.$loaded()
.then(function(events){
$scope.allEvents = angular.map(events, function(event) {
return event; // you may want to replace this line - I am not very familiar with firebase.
})
});

Handling page or tab change in angualajs

How to detect unsaved page changes check while moving another page or tab in angularjs 1.5 application.
One of approach is using directives however how to pass related form named to the directive instead of using hard coded solution?
I tried using the service approach as mentioned below but my nested view controller is not able to access the form name. Iam getting $scope.myForm as undefined.
You can handle page change with the event $locationChangeStart for ng-route or $stateChangeStart for ui-router (perform the logic you want inside):
$scope.$on('$locationChangeStart', function(event) {
if ($scope.myForm.$invalid) {
event.preventDefault();
}
});
To tab change etc, you can disable your tab with something like or watever approach you prefer
ng-disabled="!myForm.$valid"
EDIT
You may look at this post to use a service/factory approach :
https://stackoverflow.com/a/25459689/5138917
The module below seem to work for me
https://github.com/facultymatt/angular-unsavedChanges

Fire an event when user moves out of speciifc route in AngularJS

I am using AngularJS 1.3. Assume I have created several routes in my application. But when user hits a specifc route/url & then tries to move to another route/url, I want to fire some event. I do not want to fire this event on every URL change.
So only when user comes out of this url http://localhost:9000/data/55677c/edit, I want to fire one function available in XYZ controller.
Here is my scenario:
I have a page which looks like this:
<div class="well">
<button id='edit-btn' type="button" ng-click='saveContent()'>
<div ng-include="'components/grid/comOne.html'"></div>
</div>
components/grid/comOne.html page contains one grid and it has its own controller which takes care of data management of the grid.
This grid is shown in two pages. One in editable mode and one is non-ediatble mode. While user is in editable mode and try to move out of the page without saving the info, I need to fire an event in order to discard ant changes user has made to the grid data.
Please suggest
If the listening controller is a parent controller you could $emit the event.
Or you could have a common service like this:
angular.module('x').factory('CommonLogic', function(){
var pageChangeListeners = [];
return {
listenToPageChange: listenToPageChange
};
function listenToPageChange(callback){
pageChangeListeners.push(callback);
}
function pageChanged(){
for(var i = 0; i < pageChangeListeners.length; i++){
pageChangeListeners[i]();
}
}
});
then when leaving that url (track that via $routeChangeStart) you can call: commonLogic.pageChanged()
In the controller where you want to take action just:
commonLogic.listenToPageChange(function(){..}).
Obviously this should be improved to avoid duplicate registration of the listener ... etc.
I hope I'm not overcomplicating this. Could you describe your use case in more detail ?
I guess you want to use $routeChangeStart:
$rootScope.$on( "$routeChangeStart", function(event, next, current) {
});
You can put this in the scope of your current controller which might be edit as your url says.
From the docs:
$routeChangeStart
Broadcasted before a route change. At this point the route services starts resolving all of the dependencies needed for the route change to occur. Typically this involves fetching the view template as well as any dependencies defined in resolve route property. Once all of the dependencies are resolved $routeChangeSuccess is fired.
The route change (and the $location change that triggered it) can be prevented by calling preventDefault method of the event. See $rootScope.Scope for more details about event object.
Type:broadcast
Target:root scope

How to reload the ionic view?

I have created a sidemenu based app, in that after login I am displaying a number of tasks. If I click on the task it will redirect to the task details page, in that page I can update the tasks.
So after updating a task I need to go back to the previous task list page. I am using $ionicHistory.goBack(); to go back.
My problem is after come back, I need to refresh the task list i.e. updated task should not be there in the task list. How can I refresh/reload the task list?
If you bind your task to a tasks array, which will be used in the task list page, it should be automatically updated.
But the question is about not displaying, newly added tasks (still my previous suggestion should work) if not, performance reasons ionic views are cached, So when you come back to the previous view it doesn't go through the normal loading cycle. But you 2 options
1 - disable the caching by using <ion-view cache-view="false" view-title="My Title!"> in your ion-view, but this is not a very elegant solution. read more
2 - use ionRefresher (my preferred). read more here
https://github.com/angular-ui/ui-router/issues/582
according to #hpawe01 "If you are using the current ionicframework (ionic: v1.0.0-beta.14, angularjs: v1.3.6, angular-ui-router: v0.2.13), the problem with the not-reloading-controller could be caused by the new caching-system of ionic:
Note that because we are caching these views, we aren’t destroying scopes. Instead, scopes are being disconnected from the watch cycle. Because scopes are not being destroyed and recreated,controllers are not loading again on a subsequent viewing.
There are several ways to disable caching. To disable it only for a single state, just add cache: false to the state definition.
This fixed the problem for me (after hours of reading, trying, frustration).
For all others not using ionicframework and still facing this problem: good luck!"
Hope this helps.
You can also listen to ionic events such as $ionicView.enter on $scope and trigger the code that refreshes the list if you haven't bound your list as #sameera207 suggested.
EG:
// List.controller.js
angular.module('app')
.controller('ListController', ['$scope', function($scope) {
// See http://ionicframework.com/docs/api/directive/ionView/ for full events list
$scope.$on('$ionicView.enter', function() {
_someCodeThatFetchesTasks()
.then(function(tasks) {
$scope.tasks = tasks;
});
});
});
Bear in mind that it's not the most proper way (if proper at all) and if you do this you certainly have a design flaw. Instead you should share the same data array via a factory or a service for example.
For your task you can also use ion-nav-view.
It is well documented. And if you are using now Ionic 2 beta you can use some of the view lifecyle hooks like onPageWillLeave() or onPageWillEnter(). I just faced the same problem and defined a refresh() function, but the user had to click on a button to actually update the view. But then I found:
https://webcake.co/page-lifecycle-hooks-in-ionic-2/
You just have to import the Page and NavController module and also define it in the constructor. The you can use for example onPageWillEnter(), which will always invoke when you go again to a view:
onPageWillEnter() {
// Do whatever you want here the following code is just to show you an example. I needed it to refresh the sqlite database
this.storage.query("SELECT * FROM archivedInserates").then((data) = > {
this.archivedInserates =[];
if (data.res.rows.length > 0) {
for (var i = 0; i < data.res.rows.length; i++) {
this.archivedInserates.push({userName:data.res.rows.item(i).userName, email:
data.res.rows.item(i).email});
}
}
},(error) =>{
console.log("ERROR -> " + JSON.stringify(error.err));
});
}
With ionic beta 8 the lifecylcle events changed their names. Check out the official ionic blog for the full list of the lifecycle events.
if you are building data driven app then make sure use $ionicConfigProvider.views.maxCache(0);in your app.config so that each review can refresh for more details read this http://ionicframework.com/docs/api/provider/$ionicConfigProvider/

is it right to do using ui-router to activate menu items. Any advices to help me understand this?

What I did is:
When a menu item is clicked, a action will be done, like deleting a user, sending emails to a group, etc. To this end, for each menu item, I define a ui-router state, and use the state url to activate the state via sref. I thought that a menu action is just a UI component for user to let users to do something, which is just a state of UI.
I was advised that I was using ui-router in a wrong way as a state url can not identify an action. For example, to delete a group of users, the state url can not tell you what group of users have been deleted.
In short, I agree with your manager while being an angular newbie myself. Angular routes are designed for managing different views of your app. I.e. define a route and corresponding view template for each view. If you add application logic into the routes, your application structure gets quickly a mess and difficult to keep clear.
To me it is much more natural that the views are managed by the routes, and each action in each view is handled by the controller of that view. If the actions grow "big", then it is worth refactoring parts of the controller into separate services. If you require some sort of "dynamic HTML" depending on the action, e.g. bootstrap modals are handy for doing that within the current view (see http://angular-ui.github.io/bootstrap/).
E.g. in my current project, I don't actually manually edit the routes at all but let yeoman angular generator to do that for me free of charge - i.e. I instantiate each new view in my dev.env using the following command (more info on this from https://github.com/yeoman/generator-angular)
yo angular:route myNewView
More info on angular philosophy can be read from angular documentation for developers: https://docs.angularjs.org/guide/concepts
You should probably be doing this actions via a method on $scope.
$scope.deleteItem = function (items) {
Service.delete(items);
};
// which is the same as:
$scope.deleteItem = Service.delete;
<a ng-click="deleteItem(item)">Delete This Item</a>
Having it in the URL just seems wrong. I mean what does that look like? www.mysite.com/delete/users?

Resources