I don't know what is the best way to force a browser refresh when using silverlight.
The scenario is like this:
We have a silverlight application hosted on IIS
Two users opens the same page and that page contains a grid with some records.
Only one of the users modify one record and save the data in the database
How can the other user see that the data has been modified unless he refreshes the page manually?
Should I implement some automatic refresh?
Thanks in advance
I would think long and hard about the requirements here before you open up a can of worms. Is the grid editable? With the automatic refresh idea what happens to the user who is in the middle of an edit? Think about alternatives. Could you possilbly check whether the data has changed at the point of saving data and then provide an appropriate message to the user? If you want the data to automatically refresh you are going to get into looking at server to client notifications e.g WCF duplex calls or constant polling and refreshing of the underlying bound observablecollection
Related
I want to show different views based on the user of my application for example if the user is admin he can see all the controls or when it is acting as user he can only see a subset of controls and UI and he can perform the limited action.
One solution that comes to my mind is sending the role information with the page as a JSON but that would require me to have knowledge of the logged in user so, basically I can first check if the user is logged in or not through the cookie? if no I can just load the lightweight version of the login page and after user logs in then I can send a new page altogether with user's profile information embedded in it.
The other approach that I see is that I can bootstrap my angular application and then check the login status and if the login is done, then bring the profile information through a JSON and update the view, but I think it would be slow and error-prone.
I don't know what is best / recommended approach.
First approach seems to be a better approach out of these 2.
Problem with the second approach is you are sending 2 requests to the server - one for login and then 2nd one to get the user role/profile. If you are choosing this approach then you may have few issues depending how are you going to implement it:
If you are updating your UI after login then you will have to decide what should be shown to the user since you don't know the user profile yet. Even if you come up with some minimal privilege UI, there will be another request to get the profile which will kind of refresh the UI again - 2 UI refreshes could be annoying for the user. Not to mention that there 2 requests going which could make your site slow.
If you decide not to update the UI after login but only after you get user profile, still the delay would be more as you will have to wait for response of 2 separate requests. Could be a major issue with slow networks(consider mobile)
If you are using the first approach, you'll get away with above mentioned problems.
We are building Xamarin forms app to run on iOS, Android and Windows 10. We are data binding view model to UI which has List View control. We want the data to be refreshed from rest service, every 3-5 seconds when user is viewing the app. We don't want the data to refresh when app is in background, but refresh the data as soon as app is foreground. I tried using Xamarin.Forms.Device.StartTimer and await Task.Delay, but this does not seem to be working very well, sometimes the data does not refresh when not in interactive debug mode especially with Xamarin.Forms.Device.StartTimer , I am not sure what is going wrong as I am not able to do logging on device. On using await Task.Delay, sometimes the Task gets cancelled. In app onresume event, code makes rest service call which fails with connection refused error.
So I wanted to know which is the best way to handle data refresh, any ideas?
Thanks in advance
At last to do periodic refresh, i used Task.Delay and a boolean variable to known whether refresh needs to be performed or not. If user navigates away from the page, i set the boolean variable to false to stop the refresh.
Our application is a one-page application created using ExtJs. For any user action, the browser tab is never reloaded and all the actions are performed using ajax. A user can open/close multiple ExtJs windows/panels within the same browser tab, and this way everything remains confined to the same browser tab.
Now, we need to integrate payment gateway in the application, which involves redirecting the user to the bank website and having her brought back to our application.
The issue is that when browser redirects the user, then all the application javascript code along with panels and windows get destroyed, and when the user comes back to the application then she finds it to be different from one she left.
As a solution to this, we were thinking of using following two appraoches:
Option 1. Maintaining the state of application - When user leaves for the bank's website then somehow we maintain the state of application - like which windows are opened carrying what data, which variables have which values etc.. and when user returns back, we generate the same application state for her.
Option 2. Have a browser pop-up window for payment gateway - We intend to provide a button which will open a small pop-up window carrying the transaction details, and in this pop-up window the entire payment gateway process will take place taking care of redirection and everything.
Option 1 is proving to be very cumbersome and complicated as maintaining the exact state is not getting feasible.
For Option 2, we are not sure if this is safe and possible?
Has anyone implemented such an approach earlier. Otherwise, what are the other options which we can go for?
Thanks for any help in advance.
I faced the problem and I implemented it using websocket/polling in the main application while a new window pops up for the payment.
After the payment is successful the main application will be notified.
That way each payment runs in it own sandbox totally unbound from the main application which makes maintenance quite easy. Note that our backend create a new session for each payment using the existing one.
I think it is not uncommon to open new windows for payment that's why I decided to go this.
I have a Silverlight App which gets its data from a database. My Silverlight app (running in the browser) retrieves the data through a web service. Pretty standard setup.
But there is some data which has to be there all the time or the App is in an invalid state - think data to fill drop downs etc. So I need this data to be "pre-loaded" into the App before it's sent down to the client so that it's never in an invalid state. Today I load this data via a web service call when my first page is initialized which can some times take a few seconds - during that time my App is in an invalid state.
Is there a way to populate data (from a backend database) in my Silverlight App before it's sent to the browser?
It is valid for an app to start and not be ready to use for a while, so long as the user cannot interact with it (or see the broken bits:))
Better to ensure your app has a splash screen/login page etc that displays until such time as the required resources are loaded. Once loaded you can set an app state to then show the main screen.
I had the same problem with a website that loaded the menu items via a service (as the text was data driven). Wound up running a progress spinner over the top (with a full-screen background).
I don't think you can. The application runtime occurs on the client's machine. I would suggest putting up a loading dialog while you bring those items down from the database.
What HiTech Magic said. Best practice for this is to use a splash screen or login page. You can also have your buttons (and interaction) disabled by default, and after the data is loaded, enable the UI. I would go with the spash screen though..
I have one problem with IE7. Let me explain the scenario
I have opened my web based application in IE7 browser in TAB1 by using normal login feature. After successful login, i entered to the application home page and i do with my normal transaction say Trans1. Now i want to open my application again in another tab TAB2 in the same browser window.. what happens IE7 won't allow me to login on my application in the login page, it directly enters to the home page and when i do one transaction say "Trans2" it is going smoothly. Now when i again went to the TAB1 and doing one transaction it is opening the TAB2 page that i opened in TAB2.
It seems IE7 is sharing same session cookie in multiple tabs. Is there a workaround for the same scenario.
Anyone have any solution for this problem.
Appreaciate your help in this regard.
Thanks,
Manoja Swaro
It seems IE7 is sharing same session cookie in multiple tabs. Is there a workaround for the same scenario.
Well no. Cookies are by design shared between all instances of the same browser, whether in multiple tabs or multiple windows. You can only get two separate sessions by using different browsers, like an instance of IE and one of Firefox.
This changes a little in IE8, but in quite a complicated way you probably don't want to rely on. See http://blogs.msdn.com/ie/archive/2009/05/06/session-cookies-sessionstorage-and-ie8.aspx
This is why you should generally not be using cookies/sessions for keeping track of partially-completed transactions; one transaction will always interfere with the other. Better to either:
keep track of all incomplete transaction data in page/form data, like hidden fields
if that's too much data to keep passing back and forth, create an ID for the transaction that is remembered through page data, and store the actual data in the database.
You can also use a unique ID tied to the page to generate more unique cookie names, eg. 'preference.1234=foo' instead of just 'preference=foo', so that each instance will have its own cookies.
Yes. IE shares session/cookie between tabs.
Try to run a new browser (i.e. from Start menu) -- it helped with older versions of IE
and it works with my IE7.
AFAIK This happens with all tabbed browsers (FF for example).
Indeed, this is how all tabbed browsers work. Cookies are shared among all tabs. However they are not shared among multiple instances of the same application, but I doubt this will help you.
This is actually a serious problem for many applications. It is very difficult to keep track of the tabs - which are open, which are closed, when a new tab opens, and when an existing one makes a request.
There is one workaround I have found, but it's pretty messy. The idea is that you have to assign a unique ID to every tab yourself. Then, when a tab performs some actions, this ID has to be posted back to the server. Depending on the architecture of your application, the ID can be passed around in URLs or hidden form fields. If you're doing AJAX, this can make it easier to find a common place to add the ID. ASP.NET also has just one form at all times, so the hidden field is easy to do.
Naturally, on the server side you must check this ID and implement your own "tab sessions" based on it.