Wanted to see if somebody can provide some suggestions/pointers on how to address this issue I am currently facing
.
Scenario is like…
I have a Page say A where search is performed and data is displayed.
On Page A there is an ActionLink which passes an ID of the selected record to the page B.
Before redirecting to page B, I need to store/preserve form data of Page A (I do not want to use session or hidden filed as data is critical).
Once user is done working on Page B, I need to save changes on Page B and redirect back to Page A.
Here Page A should make a Post request based on preserver form data in step 3. Purpose is to display back searched data that was there before redirecting to Page B.
Something like..
View A
// Search textboxes here
// Search data list here with ActionLink column
View B
// more controls here
// Submit button - saves changes on this page.
// after submit button processing need to go back to View A
// and display the same Search data List based on Seach textboxes values
// those were entered by user before coming to this View B.
// Ques: Not sure how to persist data from View A between calls to View B and then View B to View A.
Does anybody has any better approach to achieve this?
For now the solution I have is...
Make an ajax POST request on ActionLink click and save the
formcollection in cache using controller.
Make default ActionLink GET request passing ID and in controller
return View B.
On View B, on submit do ajax POST request to save data on Page B and
return data from cache in ajax success function.
Make another ajax POST request using data retruned in above ajax
success to display View A.
Thanks in advance
If you're relying on full page refreshes then you need to use Session. You didn't give a reason as to why you don't want to use it, but Cache object is totally inappropriate for this purpose as it can be cleared out if the server needs to regain some memory, as well it is shared between users. Session is specifically built for the purpose you're describing - preserving data between full page refreshes.
Alternatively I would look into building your site as a Single Page Application, aka, you don't do full page refreshes between navigation, and can store data in a javascript object on the client. Due to the fact you put a lot of emphasis that the data is critical, the Session might be safer though as your javascript objects will get cleared out if the user accidentally navigates away from the page, where is a server based session object will preserve it for the duration of the session lifecycle.
You can also store the data in a cookie/local storage object (html5), but this is probably overkill for what you're doing.
Related
I have a page with a form that accepts a list of account numbers into a text box, a bulk search essentially.
This does posts to the server, does a validation exercise and then if sucessful redirects to a display page.
Currently the list is added as a GET variable in the URL to the display page. This is limiting in that it means users can mess with it and larger data sets may be a problem. It also allows for a bypass of the validation but this is accounted for.
I see 2 general solutions which are basically variations of 1 theme:
Save the list to a DB and pass a key to load this to the diplay page.
Save to MemoryCache and again pass the key to the display page.
Based on these options it seems that 1. is better if I need multiple IIS node but needs manual cache cleanup where 2. will clean it's self up but may be a problem if I need to scale. This will be an intranet applcation so scale will probably not be required.
Is there a "industry standard" approach to this class of problem. I'm coming from the winforms world where keeping track of state wasn't an issue.
I don't think you really have to redirect to the display page at all. From the controller that gets the user input and prints the result just return the View that should render the results like:
public class SearchController : Controller
{
public ActionResult SearchForAccounts(string[] accounts)
{
var searchResults = db.Search(accounts);
return View('ResultsView', searchResults);
}
}
If you really really need to redirect, I guess you chould save the results into the application Cache and later if you need to scale you could use a Redis Cache provider for example, but again you should be able to show the required view.
Whether it's Webforms or MVC, I recommend not getting into the pattern of separating validation/processing and results into separate pages.
I'm guessing that if the data is invalid you want to put it back on the page so the user can edit it. (That's a guess inferred from what you're asking.)
You can post the data, and then if the data is valid then the "result" page shows the results. If the data isn't valid then the page can re-render the input form, populate it with the original inputs, and display a validation error. That way the user can modify their original input and try again. (Just be sure to escape/unescape if you're taking user input and reflecting it back onto the page.) That's easier if the form is a partial view (MVC) or a user control (Webforms.)
I have two pages called test1.aspx and test2.aspx.
In the test1.aspx there are some hidden fields.
I am first storing some value to all hidden fields and redirecting to another page called test2.aspx. when I am coming back to test1.aspx, I am losing the values of hidden fields.
How can i make the values of hidden field as it is even after coming back from another page. I can't use session or any other server side state management techniques.
Are you using Server.Transfer or Reponse.Redirect to navigate to the next page?
Reponse.Redirect destroys the history of the current page in the web server, while Server.Transfer keep the history.
Try: Server.Transfer("test1.aspx")
Enjoy ;-)
I have created the webpage default.aspx inherited from Master page. I have used ajax update panel on default.aspx.
There are 3 textboxes on default page. When I click on submit, the error occured on the page and there is link Show Error which redirects to showError.aspx which shows the error details.
On showError.aspx page there is back button which onclick return back to default.aspx. In this process it looses the viewstate of textboxes at default page.
So how can I preserve the viewstate when ajax is used ?
this is typical behavior for webforms. viewstate is valid between postbacks. meaning you are posting to the same page(url). if you leave that page and go to another, then you are abandoning viewstate. the next time you return to that page viewstate is reset. the server doesn't know how you got the page (address bar, html button/link, or using history). it just knows you did arrive.
the short answer is you don't preserve viewstate. doing so defeats the purpose of viewstate. it's only meant to exist between postbacks. There are ways to preserve the user input, but this may require conceptual and design changes to how you are managing the validate and errors.
for example.
1. validate the user input (required, range, regex, etc.
2. validate the business rules (customer is valid, date is after point in time, customer's account is not on hold, etc)
3. process the request.
1 & 2 should catch most problems and return the user to the same page, with fields populated and a list of errors why the request was not successful.
If an error occurs at #3 then it's truly exceptional and should abandon all work. the user shouldn't return to the previous page with state preserved because something really is wrong that you were not expecting.
and all of this is indifferent of what the input is and whether or not you use ajax.
I'm new to ASP.NET. I'm designing a user interface in Asp.NET and C# where the user can login and then launch an application. When using this application the user has to fill out a form that is 10 pages long.
So, I have used navigation menu and designed the interface in such a way where every page is different menu item and it is a static menu. The user fills out the details on the first page of the form and saves it and the data gets saved in the database.
The problem is he moves to the other page by clicking the menu tab; when he comes back to the first page by using the menu tab for that page all the filled in data is gone and he sees a blank page. I know that is how it works but I want it in such a way that in one sitting when he is filling out the data on the second page (after filling the data on first page) on reverting back to the first page he should be able to see the data that he had filled out.
What concept can I use? I'm not sure view state will be helpful in this scenario.
You should look into using the Session State variable for storing his information over the entire session. If the user is logged in you should think about storing his information that he enters in a database and having a Boolean state of "ApplicationFinished" to check if he has finished it or not. Otherwise I would have a call on each page to retrieve information from the database that has already been added, so that he can fill out information at different sittings or all at once.
http://msdn.microsoft.com/en-us/library/ms178581.aspx
Session State may be too long term for you, and if that is the case do some research on ViewState. There are a lot of different ways to tackle a problem like this. It all depends on which technology will fit your needs the best.
http://msdn.microsoft.com/en-us/library/ms972976.aspx
Also, if you're using a tab system think about using the AJAX tabs so that the data will remain on the forms even while tabbing through the different tabs.
http://www.dynamicdrive.com/dynamicindex17/ajaxtabscontent/
Well, if you are write the data on database, i guess the best (fast) workaround is to add a column named "completed" to the table the hold this informations. If the flag "completed" is not setted to 1, you load the database information and fills the page controls.
When you create a new record in the database, get the ID of the record and set it on Session. If the user gets back to the first page (previous page), you can recover the information ID and load the data.
As long as you are learning new things... add jquery to the list and leverage the JQuery Wizard Plug In. It will allow you to integrate your "10 page form" into a single unit, which can then be sub divided, routed and managed more easily. You can leverage AJAX to save each step, while offering built in navigation and validation methods.
I would suggest that you switch to using client-side javascript to control your tabs. That way your form data stays in the fields when you switch back and forth between tabs. You can use javascript buttons to guide the user from tab to tab.
I've done this using JQuery. I actually had 150 fields that needed to be captured (they were all required). I group like data on different tabs and then had buttons ('< Previous', 'Next >') which would activate different tabs.
When they are done, then display the 'Save' button.
This not be what you are looking for, but if your problem is that you want all of the input of a previously filled page to show up when a user navigates back to it, and you have already saved all that information, then you can try something like this:
HTML
<input type="text" id="yourID" name = "yourName" value = "<%=data%>"/>
Then all you need to do is set data to public in the code behind. Then to get the value for data just make a call to your database.
Make sure that you make data empty on the init call public string data = ""; or whatever type it is. This way if there is no info, then it will be blank, and if there is saved info, then it will be filled in.
You can also attempt to pass all the data through params in the url like so:
C#
Response.Redirect("webpage.aspx?data=" + data + "&data1=" + data1);
Or though javascript:
window.location = ("webpage.aspx?data=" + data + "&data1=" + data1);
To get the request do this:
if (Request.Params.AllKeys.Contains("data"))
{
data = Request.Params["data"];
}
This way is less ideal though if there is a lot of data being passed.
usually I would setup a GET POST Redirect cycle, however I have run into a situation where rather than redirecting, I need to just return a new view. The problem with this is that the new page has the URL of the previous page (because I haven't redirected, i've just returned a new view). Is there any way of changing the url of page presented to the user without redirecting?
I am actually implementing a wizard where I need to persist data between pages, however I have no way to persist data through a redirect (TempData is disabled..) which led to the above approach. A possible solution is to create a table to store the temporary data that I need to persist but this is undesirable. I also don't want to end up with one view with every field for the wizard and just use jscript to hide show the different steps.
Any help, tips or general advice would be really appreciated.
Thank you.
No, you would have to redirect to change the URL effectively.
You can always POST to a new URL, right?
In your wizard, you could do
myWizard/step1
myWizars/step2
etc
There's no problem with that, except that they'll repost if they hit F5.
Between the the posts, you can model bind and then print out html hiddens.
ViewState 2.0
You can make your View a strongly-type view so that you can pass your data to that view when you return it. Just make a view-model out of the data you want to persist.
return View("MyViewPage", objData);
Perhaps you could do something like this?
Wrap the view with your form up in a partial.
Have it post to the second URL.
Perform validation and return the same partial if it fails.
Otherwise, return your second view.
You'll have to make your form a child action in order to stop the PartialViewResult from being the entire rendered markup on the POST, though (and post to the parent action), so this does have some limitations in terms of what you'll be able to render (e.g. you might have some issues to work around if you want your layout to change for the second page).
This way you can keep your ModelState intact for your validation errors, return your second view directly from the POST and still have a different URL.