I have a challenge in my app that I need to resolve quick, the thing is I have to prevent the current component from being destroyed when I navigate backwards using this.location.back();
Based on my project I have an About Us link in my Login component that navigate to the About component using this.routerExtensions.navigate(["/about"]);, in the About component I added the back button that goes back to Login component as I described in the first paragraph. My problem is that the About component is destroyed and I need to prevent that.
Is there any way I can implement this functionality?
Thanks!
Related
So I have a Shell that has a home page and a settings page.
The settings page makes changes to a singleton service that the home's ViewModel is binded to (MVVM).
I have set up break points on the PropertyChangedEvents of elements on the Home page and they hit as soon as changes are made to the service's properties and their PropertyChanged is executed.
However, upon going back to the home page via the Shell, the page's UI only updates when the page is active and visible. This causes fields to flash when they change. But the breakpoints suggest that they should have updated before.
Is there a way to force refresh the UI before or are there any other alternatives?
For now I have made my view perform a Fade In animation so that changes to the ViewModel don't cause flashing.
Even I have a Xamarin Forms Shell app, and I also had the same issue, So what you can do is, Make the common properties Global as in make those properties in App.xaml.cs and mark them as static.
So when the User changes the property on settings change the App.PropertyName.
Then on the OnApearing method of homepage call a method on the ViewModel say LoadDataValues() and read the App.PropertyName and modify the UI as needed.
What this will do is just before the HomePage appears it will keep the UI of HomePage ready.
Let me know if you have further issues.
I have moved my project to prism 7.2
I have quite a few "OnNavigatingTo" and replaced accordingly with InitializeAsync or Initialize
If I remember correctly "OnNavigatingTo" was firing every time you navigated to a page whether to or back. If I was navigating back to a page it would fire whilst Initialize doesn't.
This whether correct or wrong is causing me issues with some of my pages where I was passing back parameters when navigating back .
Is this the intended behavior?
thanks
OnNavigatingTo was only ever supposed to fire once. It's intent was to initialize. There ended up being cases where it fired more than once. Anything you require done once should be placed in IInitialize.Initialize anything that should be fired each time you navigate or requires some logic like Navigated Back to... should be in INavigat[ed|ion]Aware.OnNavigatedTo.
It was this confusion that led so many Prism users to request that the support be dropped and a new API be introduced that made the intent clearer.
I have a contact addition form that can be navigated to from multiple screens in our application.
Once the form is submitted, I then take the user to a screen to view the contact that was added.
When the user then makes use of the back button it should take them back to the screen that they originated from.
This might be the Android back button or one that calls the RouterExtensions back function.
I have made use of the navigate extra replaceUrl when navigating away from the form to the view page.
I have also tried using the skipLocationChange extra when navigating to the form but this creates more issues.
I have created a simple playground page flow that creates not quite the same issue but does throw an error that I don't know what to do with either:
https://play.nativescript.org/?template=play-ng&id=BfVcGZ&v=2
In our app, by making use of the replaceUrl extra, the back button does take the user to the correct page.
However, there is a brief moment where they see the form again. This isn't an ideal user experience.
In the linked Playground I do get an error:
Cannot reattach ActivatedRouteSnapshot created from a different route.
This seems to tell me that replaceUrl is indeed removing the page from the route table.
However, the page isn't destroyed yet and so the app is trying to show a page that it shouldn't.
replaceUrl is not yet supported by Page Router Outlet, there is an open feature request, you might want to register your vote on the feature and follow up there for further updates.
I have a few pages in an Application that require A-Synchronous calls to be made for about 2-3 minutes to get Synchronized, the user may navigate away from that page during Synchronization and can come back again after visiting multiple pages and the sync continues all the time he is on other pages as well, when I go to a page from sync-page and press the Back button everything works fine.. but when i go to a page and navigate back to sync-page from Application Bar a new Instance of the Page is created and the Sync is just like Re-started.
Now i know every thing is working fine since new instance of a page is created when i call NavigationService.Navigate() , but what should i do in this scenario ? How to get the old instance of a page if it is there ?
Thanks...
You can't get an "old" instance of a page and it's not guaranteed that a backwards navigation will reload the previous instance of the page, it may be a new instance of the same page, but restored to the same state (assuming you saved any).
If you are trying to provide backwards navigation from the application bar then a) you probably shouldn't because that's what the back button is for, and b) you should make sure you use NavigationService.GoBack() instead of NavigationService.Navigate() because Navigate will always launch a new instance of your page.
If the page you want to get to is not the previous page, then it sounds like you are trying to implement non-linear navigation for which there is a recipe on the App Hub.
By the sounds of your scenario, you should handle this long running process separately (away from the view) and then display it's progress or results in a view when the user navigates to the relevant page.
I have a very strict requirement to use POST to pass in request parameters to my application upon entry. Once entering the application (page1), entering form information and continuing to the next page (page2) via a commandButton, the expectation is that the data will be posted and later read from a session scoped manage bean. All works well except when using browser back on page2 to navigate back to page1.
I have tried adding a redirect tag on the navigation rule that navigates from page1 to page2 to no avail. I have also tried this implementation of the Post-Get-Redirect pattern (http://balusc.blogspot.com/2007/03/post-redirect-get-pattern.html). Am I missing something obvious here?
Abel, the scope of page1 is request.
The solution we came up with which is no means ideal is to disable browser caching on the previous page. What this means is that whenever you refresh the page using the browser refresh button or click the browser back button, the browser will indicate that the page is expired and prompt a warning asking whether you want to re-submit the request.
We do have a work around which is to provide navigation buttons within the webpage but the idea was to support browser back. This would be easy using GET parameters, but POST provides additional complexity which we have decided to mitigate by by providing our in-house navigation buttons.