I can see the event $routeChangeStart in my controller, but I don't see how to tell Angular to stay. I need to popup something like "Do you want to SAVE, DELETE, or CANCEL?" and stay on the current "page" if the user selects cancel. I don't see any events that allow listeners to cancel a route change.
You are listening to the wrong event, I did a bit of googling but couldn't find anything in the docs. A quick test of this:
$scope.$on("$locationChangeStart", function(event){
event.preventDefault();
})
In a global controller prevented the location from changing.
The documented way of doing this is to use the resolve property of the routes.
The '$route' service documentation says that a '$routeChangeError' event is fired if any of the 'resolve' promises are rejected.1 That means you can use the '$routeProvider' to specify a function which returns a promise that later gets rejected if you would like to prevent the route from changing.
One advantage of this method is that the promise can be resolved or rejected based on the results of asynchronous tasks.
$scope.$watch("$locationChangeStart", function(event){
event.preventDefault();
});
You can do like this as well. Benefit of doing this way is that it
doesn't trigger through if() statement with $on ...as you well see
that below code will trigger no matter what the condition is:
if(condition){ //it doesn't matter what the condition is true or false
$scope.$on("$locationChangeStart", function(event){ //this gets triggered
event.preventDefault();
});
}
Related
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
My user can leave a state but before I want to show a modal dialog "Do you want to save?"
ONLY if the user data is dirty that means changed.
What I do NOT want is to stick a isDirty property in my EditController to the $rootScope go to the stateChangeStart event and check there for isDirty and then show/not the save dialog.
Prevent global variables says every javascript beginner book...
1.) What is then the pro way to prevent a state change without hacking the $rootscope?.
2.) Are there any helper libraries for ui-router which enhance the ui-router offering function hooks inside the controller to encapsulate the ui logic?
(1) According to the docs under State Change Events
$rootScope.$on('$stateChangeStart',
function(event, toState, toParams, fromState, fromParams){
event.preventDefault();
// transitionTo() promise will be rejected with
// a 'transition prevented' error
})
You could change $rootScope to $scope wherever appropriate and works.
Under Attach Custom Data to State Objects, you can pass on custom data.
(2) I'm not sure what you're asking but factories/services/providers would really help.
Using $transitions.onStart (angular-ui-router 1.0.0-rc) you can return a boolean. If false the transition will be cancelled.
$transitions.onStart({}, function (trans) {
var answer = confirm("Want to leave this page?")
if (!answer) {
return false;
}
});
Here is the documentation: https://ui-router.github.io/ng1/docs/latest/modules/transition.html#hookresult
Though at the time of writing it is not a part of the stable release, the 1.0 release of the UI-router will use the return value of onEnter/onExit to prevent navigation.
See GitHub issue 2219
I send request to the server and want conditionally redirect to another page (not angular) after response is received. Thus navigation happens inside then part of a promise.
I tried:
$location.path(url)
and
$window.location.href = url;
$windo.location.reload();
nothing works.
But if I wrap either of these two calls with setTimeout(navigate,0) redirection occurs.
Seems like Angular guards url during digest cycle.
Can anyone clarify or share the links explaining what really happens.
After doing the change, and before ending the promise handler, try doing:
$scope.$$phase || $scope.$apply();
That should populate the changes.
There doesn't appear to be a built-in way to update the url without running all of the other processes, e.g. invoking controllers.
The option "reload", only works with $location.search()
Is there a method, or approach to achieve
How may I achieve something similar to:
$state.go('stateName', params, {justChangeTheUrl: true})
With Angular UI-Router?
If you just want to change the url without having that change processed by ui-router then you can use the following perfectly acceptable hack (coffeescript):
scopeOff = $scope.$on '$stateChangeStart', (e) ->
e.preventDefault()
scopeOff()
$location.path 'just/change/the/url'
Notes
Normally making a change to the browser url via $location.path() would trigger ui-router to begin its processing. This processing starts with the ui-router specific event called $stateChangeStart.
In the code above, however, you are catching and, via e.preventDefault(), throwing away this initial call to $stateChangeStart event and so preventing ui-router from processing the url change.
The watch on the $stateChangeStart event is 'single use', that is the code automatically detaches itself from the event after one run (this is what the call to scopeOff() is doing).
The net effect is to change the url in the browser without triggering ui-router processing and to only apply this restriction to the one url you have just changed. Neat, but not as neat as the new deferIntercept feature that will be with us soon.
Define state parameter in url
$stateProvider.state('stateName', {
url: '/state/path?reload'
});
But be carefull, every $location.search() change on reload param will trigger $stateChangeStart event, and your controller will be recreated
Ramping up on angular, and ui-router
And struggling with redirecting to a different state if a precondition is not met:
I tried using an interceptor: (How do I preform a redirect in an angular interceptor).
But someone mentioned that handling $stateChangeState would be more appropriate. But I am still running into an infinite loop:
/**
* Check here for preconditions of state transitions
*/
$rootScope.$on('$stateChangeStart', function(event, toState) {
// which states in accounts to be selected
var accountRequiredStates = ['user.list', 'user.new'];
if(_.contains(accountRequiredStates, toState.name)){
event.preventDefault();
ApiAccount.customGET('get_current').then(function(resp){
// if I have a selected account, go about your business
if(resp.hasOwnProperty('id')){
$state.go(toState.name);
} else { // prompt user to select account
$state.go('user.select_account');
}
})
}
});
Can anyone suggest a better pattern (one that works)
Thanks!
Note: Similar problem different approach here: How do I preform a redirect in an angular interceptor
I don't think there's anything wrong with the general way you're trying to do this, though I'm not an expert. I do see a flaw in the implementation which looks like it could cause an infinite loop. Let's say the user tries to go to 'user.new' state. Your $stateChangeStart listener intercepts that, cancels it, does your customGET; then if the inner if condition is true (resp.hasOwnProperty('id')), you try to send the user to the same 'user.new' state. At which point, your $stateChangeStart listener intercepts it, cancels it, etc., over and over.
The way I avoid this problem in my code is to have a variable (in the service where I declare the listener) to help me bypass that check:
var middleOfRedirecting = false; Inside your inner if block within the resp.hasOwnProperty('id') check, set middleOfRedirecting to true; add a condition at the start of your $stateChangeStart listener to only call event.preventDefault() and redirect if middleOfRedirecting is false. You also would need a $stateChangeSuccess listener to set middleOfRedirecting back to false, resetting it for the next state change. (I feel like there should be a better way than this, but it at least works.)