I have a generic 'form page' user control that we use that allows editors to insert whatever kind of html form they want to inside of it, and it handles all of the form posts.
My question is, is there a way to store the vanilla non-asp form entries in the viewstate or otherwise save the entries on a form post, in the case that some server-side validation fails, so they can be restored when the page refreshes?
We currently already do upfront javascript validation that catches the majority of the input errors. We store all the form post data in a db before we do further processing, and some of the entries contain junk (spam we wish to ignore) or only partial info (i'm assuming those are cases where the user doesn't have javascript enabled). I'm trying to catch these last fringe cases so we do not process them.
If I am understanding this correctly,
1>User fills form
2>Clicks submit
3>Error detected on the server side
4>The Html posted back should contain the form i already filled with an error message on top.
Have you considered using JQuery Ajax?
The jquery ajax will post to a web method. The web method returns a JSON response. If the response is success redirect user to the next page, else show error on top of the page.
That way you don't need to maintain the state of the user input (since it is never lost).
If you dont know what the form fields are ahead of time then I would reccomend that you look into partial postbacks.
Or else post the forms via ajax.
you could store the text HTML in
<asp:HiddenField ID="hid1" runat="server" />
this will be passed in View State
Related
I have an ASP.Net form (Page1) where the user enters some data and then clicks the submit button.
As part of Page1, I have some Validators, including a CustomValidator which needs to do its validation back on the server.
When the user clicks the submit button a post is done to Page1 and the validation routine is run on the server and as long as I check Page.IsValid in the button click routine the form knows whether things have passed or not.
When the validation doesn't pass everything properly goes back to Form1 and the error message is displayed.
When the form does pass validation, I want to pass the data that the user entered to a second form (Page2) so that Page2 can be rendered correctly based on the data the user entered on Page1.
Is there a generally accepted way, or best way, to pass the data to Page2? Here are some ways I know about:
Call Page2 with a query string: This won't work as I need the data to not be visible to the user in certain cases.
Use the PostBackUrl on the submit button to go to Page2: As far as I know, this won't work correctly because then the server side validation routines for Page1 won't be run.
Use Session Variables: I don't know of a particular reason why this would be bad.
Use Server.Transfer: I don't really have any experience with this.
I would think that this would be a pretty standard thing to do but I'm having a hard time finding any information on the correct way to do it.
If you don't have a form of secondary storage for this data, using either Session storage or Server.Transfer would work.
You might find Server.Transfer is a little neater as, this way, you'll retain your POST values across the transfer. This will potentially save you a lot of cumbersome code playing around with session state, which, depending on how complex your forms are, could open the way to all kinds of unusual behaviour that you'd have to predict and plan to deal with in advance such as what happens when a user clicks the "back" button or - if you're posting across multiple pages - what happens when a session expires (plus Servy's examples of having multiple tabs open on the same page(s), all sharing the same session). Working with session state can be messy.
Perform your validation on PostBack then, if Page.IsValid, do:
Server.Transfer("/FormPage2.aspx");
Server.Transfer preserves Request.QueryString and Request.Form, so you can pick up your POST values on FormPage2 and do whatever you need with them here - whether it be using them for conditional logic or rendering them out again as hidden fields to join them up with the values from the second page of the form (bear in mind that if you're doing this you'll have to revalidate the hidden inputs at this stage).
http://msdn.microsoft.com/en-us/library/y4k58xk7.aspx
I have used session state for handling complex forms in the past and found myself wishing I'd used Server.Transfer, which I plan to use for all similar endeavours in the future, unless I have a very good reason not to.
You might also consider using a multiview, but in my experience these can be very messy.
Hope this helps.
I think that the easiest solution would be to specify a PreviousPageType directive. It specifies a type that the page should expect to receive and you would do a normal POST to that page.
On the second page of your application, use the following directive:
<%# PreviousPageType VirtualPath="~/FirstPage.aspx" %>
You will be able to access the properties exposed and check for validity by using something like this:
if (PreviousPage != null && PreviousPage.IsValid)
Using the Session object is a standard way to pass information across forms.
#Servy gives a good explaination (in the comments below) on how Server.Transfer can help you in this case.
The other options you stated all have problems, just like you mentioned...
If you want to use Session:
In the postback of Page1 you can set the values:
Session["myVar"] = <Data you want to pass to page2>
In page2 in the OnLoad:
if (Session["myVar"] != null)
{
myVar = Session["MyVar"]
}
You can achieve this with Server.Transfer by adding a property to your page1. In your second page in page_load for example:
Page1 prev = Page.PreviousPage as Page1;
if (prev != null)
{
// access your property here and set up the page
}
Server.Transfer can safely receive a query string without fear of the user seeing it.
Instead of Session use Context.Items.
Context.Items["validationProblems"] = "...";
Server.Transfer("FixProblems.aspx");
My other comment is that in my experience it's more "standard" to keep the validation UI contained in the same form that's collecting the information. This enables "real time" feedback. In practice I think it's better to give a user information that their doing something wrong as early as possible.
Note, that's just in my experience though.. it's a big world.
It may be more that you presently require, but one alternative is to save the data in a database:
http://msdn.microsoft.com/en-us/library/6tc47t75%28v=VS.100%29.aspx
http://www.asp.net/web-forms/videos/how-do-i/how-do-i-set-up-the-sql-membership-provider
I need to populate a form in the main page which on being submitted opens a lightbox which contains another form .
I was planning to submit the form using Post as that seems to be the only way I can define which iframe to open in the lightbox .However my question is that how do I pre-populate the second form with the first forms data when I use the submission as POST
I am using ASP.NET and C#
I apologize for the naive question but I am still playing around with ASP.NET
We dont have many details on items such as - is there a redirect? whats the second form? how are you handling controls.. etc
Check this out to start. If you really need to send values across separate requests there are various ways to do this, but specify if this is what you are trying to do.
http://msdn.microsoft.com/en-us/library/ms178139.aspx
Use the Form collection in the Request object on the second form. The name in the collection is the same as the name in the name/value pair you're using in the post.
TextBox1.Text = Request.Form["someName1"];
TextBox2.Text = Request.Form["someName2"];
Etc.
Ive noticed that on my pages which uses updatePanel I get an error after ctrl+r or hitting F5. When I then try to do asynchronous postback there is the message:
the state information is invalid for this page and might be corrupted
I ve read that Response.Cache.SetNoStore(); but on my instance of ff 3 it doesnt really work.
Is there any other solution ? I user ASP.Net 2.0
thanks for any help
This problem occurs specifically when you postback before the EventValidation field has been rendered. If EventValidation is enabled (by default), but ASP.NET not able to see the hidden field when you postback, you also get the exception. If you submit a form before it has been entirely rendered, then chances are the EventValidation field has not yet been rendered, and thus ASP.net cannot validate your click.
One work around is of course to just disable event validation, but you have to be aware of the security issues.
In general it is not advisable to disable EventValidation. To quote MS documentation
"It is strongly recommended that you do not disable event validation. Before disabling event validation, you should be sure that no postback could be constructed that would have an unintended effect on your application.".
http://msdn2.microsoft.com/en-us/library/system.web.ui.page.enableeventvalidation.aspx
Also have a look at a detailed post that talks about several advantages and disadvantages of disabling Event Validation.
http://odetocode.com/Blogs/scott/archive/2006/03/21/3153.aspx . This link does have some devs talking about the samE kind of error that you are experiencing.
this can happen when you load some content/ controls with ajax into a containing div (assuming the div is within the form element of the body).. remember when you're using webforms they all got the <body><form id="ctrlsomething">stuff</form></body> format ... when you do a postback, form gets submitted and the content controls/elements do not match original ones (remember you added stuff)... hence the error.
one way to overcome this is by adding element via javascript/jquery at the start
$('body').append("<div id='myframe_that_ajax_will_fill_with_stuff'></div>");
this adds <div id='myframe_that_ajax_will_fill_with_stuff'></div> within the body, after </form> so you'ld be fine
other options is disabling eventvalidation/viewstate on page level, but this can lead to security holes
I have an "Edit Profile" lightbox on my page, which posts to the controller via jQuery ajax. I handle the response in the jquery end instead of returning a View. However, when the profile is saved, I need to refresh the values on the page displaying the popup. How could I achieve this in MVC2? For example, if the user changes her name and avatar (in the lightbox), after she saves the profile, I'd like to update the avatar and name everywhere it occurs on the page.
Well what i would be doing is make your Controller return a PartialViewResult, which the end result is basically HTML.
The Partial View would be the popup itself, so essentially your calling your Controller method via AJAX, doing your server-side work, then re-rendering the Partial View to the client.
Have the action you post to via jQuery return a success for failure message. If it is a success, change the avatar/name/etc on the page using the values already in the textboxes (i.e.: the values you posted to the controller). If it is a failure message, display the validation errors.
In your jQuery AJAX, everything can be done in the callback function of the AJAX request.
Prabhu - both your profile page (i.e. the 'main' div contained within it) and the popup div should be partialviews. on posting the popup back to the server, you should requery the main page partialview and return the appropriate html, targetting the 'main' div.
that's certainly the approach that i take for a very similar task.
So, I have a page that looks like the following:
alt text http://img704.imageshack.us/img704/5973/croppercapture3.png
This is my basic messaging inbox. I have 2 pages right now, Inbox and Sent (there will eventually be others). These both share the same View, and just have 2 different actions to populate the appropriate data.
The elements on the right-hand side (the message list) is a partial view which has its data populated based on my two controller actions Inbox(int? page) and Sent(int? Page).
So, I have one view "MessageView" and one partial view "MessageList" shared between Inbox/Sent.
However, I now have to get those arrow buttons ("<" ">") working using Ajax. I know how to use jQueries ajax calls well enough, and I know how to render the result of the action call (which returns a partial view).
The problem comes from the fact that the javascript that makes these pagination ajax calls needs to know two things:
What the current page is (whether it be /messages/inbox or /messages/sent)
What the current page is (specified in the query string, ie /messages/inbox?page=2).
Without knowing which page I'm on (Inbox or Sent), it wont know which url to make the ajax call on. Should it make the postback to /messages/inbox or to /messages/sent?
If I wasn't making these messages load with Ajax it would be as simple as loading the appropriate url into the link tags for the "<" and the ">" buttons. But I can't, because part of my requirements states that it must load the messages below without visibly refreshing to a new page.
In JavaScript you can check window.location.pathname to see the pathname section of the current’s page’s URL.
window.location.search gives you the query string.
When the user clicks the Inbox or Sent buttons, you need to rewrite the URLs in your arrows so that they point to the right place.