I am trying to diagnose some behavior on our asp.net based website. Following is the scenario:
User is on page1 and executes query that populates a GridView with data and a hyperlink that redirects to page2.
User clicks on the hyperlink and is redirected to page2 where they can edit data. At the bottom of page2 is a Cancel button that should take the user back to page1.
I would like to have the Cancel button return the user to page1 with their search results populated. This works if the click the Back button on my browser but I cannot emulate this behavior with a response.redirect.
I've tried a number of combinations of the following:
reponse.redirect(request.url.tostring())
and every instance seems to refer to page2 and NOT page1
Do you have any suggestions?
This will depend a bit on which version of .net you are using. In .net Core, the headers on the Request have the info you need.
Request.Headers["Referer"]
This has the full url with the query string. You can catch this in the controller and set it to a value on the view model (or stuff it in the view bag).
if (Request.Headers.Keys.Contains("Referer"))
ViewBag.Referer = HttpContext.Request.Headers["Referer"];
else
ViewBag.Referer = "";
Then use a string.IsNullOrEmpty(ViewBag.Referer) in the view. I added the check for safety reasons, why if they got to the page directly without a link?
You can also use Request.Headers.TryGetValue. It is a little safer as there could be duplicate headers but there really shouldn't be, expecially here.
Related
I am developing a website using ASP.net.
In my home page I have 14 tree view controls. They were placed under Jquery tabs. So when a user click a tab it only appears one treeview. So in tree node changed event currently what I am doing is passing the values from query string to another page. this query string doesnt have any sensitive data. I have to pass what is the selected Tab Id and selected tree node Id.
Response.Redirect(String.Format("~/Display.aspx?tab=1&type={0}",treeview1.SelectedValue), true);
But you know URL is ugly. I dont want to use Friendly URL thing now.
So what I did was I put 2 hidden fields values in my home page and I set them when I click the tree node.
So then from the source page I used this code to acess this.
if(Page.PreviousPage!=null)
{
string tab= Page.PreviousPage.FindControl("hftab").UniqueID;
string Type= Page.PreviousPage.FindControl("hfType").UniqueID;
}
But Page.PreviousPage always return NULL. So how to solve this probelem without using sessions and query string. I just want to pass two non sensitive data behind the scenes.
IF this is about Cross page postback thing How to do this cross page post back in node change event? Is it ok to do a Cross page post back for to get only 2 values that I needed?
The method you are trying is only possible with "Cross page posting" mechanism. When you set PostbackUrl property of a server control like button, and set the PreviousPage property of Page directive on destination page; then only you will get Page.PreviousPage values.
Here are some reference:
1. http://www.codeproject.com/Tips/604553/Postback-and-Cross-Page-Posting-in-ASP-NET
2. http://www.aspdotnet-suresh.com/2010/05/cross-page-post-backing-in-net.html
I have one button on page, page name abc.aspx . when user click on that button
it should redirect to finishwork.aspx page.
After finishwork.aspx page user must not go back to abc.aspx page. when user press back button in browser, he should be redirect to workallreadyfinish.aspx page
Disable caching on that pages and avoid caching the page.
Response.Cache.SetExpires(DateTime.UtcNow.AddMinutes(-1));
Response.Cache.SetCacheability(HttpCacheability.NoCache);
Response.Cache.SetNoStore();
location.replace() can be used to replace your page in the history.
There are many ways to accomplish this, but, as you are using ASP.NET and I'm going to assume, WebForms, why don't you make use of the <asp:Wizard> control?
You will be able to have a much detailed control over your steps and block the user to go back and all sort of nice things.
If you want to take the normal way, you can always warn the user that the page will no longer be valid using a javascript event.
You can also make use of hashing and submit the form by an ajax call instead of a normal POST
You can write a cookie once the form is submitted and the next time, show such warning, so even if the user goes back and press the Submit button again, you will not care. Remember to erase the Cookie on if (!Page.IsPostBack) { ... }
Having your user workflow around the browser back button is not such a good idea.
Browser back buttons are not entire in your control.
If you want to provide a logical back in your application, use a back button in your application.
If you only want that a user cannot go back to a page, you should tell the browser not to cache it set the page to expire.
You can use javascript function for this:-
function disableBackButton()
{
window.history.forward();
}
setTimeout("disableBackButton()", 0);
I have some pages in my website and a left menu control. Control helps to navigate from one page to another.
My query is -> While user try to navigate to another page, I want to impose some validation like in the current page if the form is not saved, user will be asked to save it by using a confirm messagebox and if user presses no button, then user will be allowed to navigate otherwise, system will first save the details and then navigate.
Edit - My page is a content page, I meant, this is using a master page.
Use the following steps
window.onbeforeunload = confirmExit;
and a function that stops/continue the page execution.
function confirmExit() {
var email= document.getElementById("email");
if (email.value != "")
return "You have attempted to leave this page. If you have made any changes to the fields without clicking the Save button, your changes will be lost. Are you sure you want to exit this page?";
}
The way I would do this is to have an onbeforeunload javascript event fire which gives the user the choice to save the form. I personally would also poll the form saving data back whist they are completing it. I think this is the method SO uses.
There is a pretty decent example over on Code Project that may help http://www.codeproject.com/KB/aspnet/AutoSaveFormData.aspx
EDIT:
If you only want to call the save method you can mark it with the [WebMethod] filter and call it using XmlHttpRequest or jQuery's $.post
i need to implement a back button for my asp.net website.I am able to use the javascript method to acheive my requirement.But using this method sometimes I need to click on the back button multiple number times to go back to the previous page.It may be because we are using jquery tabs in our website.To focus on a particular tab,other than the 1st tab on page load I am using Page.ClientScript.RegisterStartupScript(....).So I am unable to take the user back to the previous page with just one click.
I also tried with asp.net-C# methods mentioned in the following link.
http://www.dotnetcurry.com/ShowArticle.aspx?ID=89
I am able to go back to the previous page, but its state is being lost.Could someone please help me in acheiveing my requirement?
Details:
I have page1.aspx,page2.aspx(which contains jquery tabs view/edit).
In the page1.aspx there are 2 buttons(View,Edit).If I click on view button it takes me to page2.aspx View tab(1st tab) and if I click on the edit button it has to take me to page2.aspx with Edit tab loaded.both View/Edit tabs contain back button.
Also from the View tab I can navigate to the Edit tab,by clicking on another Edit button present in it.
Thanks.
The methods you have covered in your question are essentially what is available to you.
You can either
1. Provide a link that uses javascript to make the client go back a page.
2. Provide a link that posts back to the server that redirects you back a page.
I am not sure why the jquery in your webform as described in your question is causing you to click more that once to go back. If you know that it will always take 2 clicks to go back you could try this method:
javascript: window.history.go(-2)
When you are using the postback/redirect method you will always be using a http GET method to retrieve the page you are returning too. If you want to maintain state you will have to do this manually i.e. save the values when leaving the page somewhere, like session or a temporary database, and when returning to the page, during the page load, check to see if the user has these values saved and pre-populate them.
I've done something similar (with automatic redirections though) and I had to keep track of the number of pages to go back in my ViewState (or Session if you're jumping from page to page):
code-behind
public void Page_Load()
{
Session["pagesToGoBack"] = ((int)Session["pagesToGoBack"])++;
}
mark-up:
<input type="button" value="Back" onclick='javascript:history.go(<%= Session["pagesToGoBack"] %>);' />
Be careful to reset the session variable when needed
Made me feel a bit dirty but it worked :)
First of all, thanks for reading.
I will describe my situation as explicitly as I can.
I have a page where users can leave comments.
Here's the commenting flow
A-1. 'comment' button is clicked
A-2. a modal popup with a textbox is shown using ModalPopupExtender in ajaxtoolkit.
A-3. User types a comment in the textbox, and click "ok".
However, when user is not logged in, expected behavior changes.
B-1. 'comment' button is clicked
B-2. a Login modal-popup with id & pwd textbox is shown.
B-3. User types ID & pwd, and click ok.
B-4. Comment-modal-popup is shown
B-5. user types a comment and click ok.
I have a PROBLEM handing this case.
When B-3 occurs, page is posted back, i log the user in, update session object, and I Response.Rediect() the page to itself to display correct logged-in status (i have to..).
After redirect, in Page_Load(), I need to check some values to show Comment-Modal-Popup.
But I'm not sure how..
Here's what i considered
ViewState
i just can't use it since the page was redirected not posted back.
QueryString
I could have add "showCommentPopup=1" on URL when redirecting, but that will leave unwanted QueryString in URL. I don't want users to misuse it.
Session
I actually used Session object. Before redirection, I set Session[ "ShowCommentPopup" ] to true. In Page_Load() if it is set, i remove it and show the popup.
using Session like i did doesn't work correctly when user opens same page in multiple tabs.
user opens two tabs(in Firefox) with same URL
user follows steps from B-1 to B-3 in first tab.
before the page is redirected between B-3 and B-4, user refreshes second tab.
if the timing is right, comment-popup is shown in the second tab.
I expect to hear great insights from stackoverflow..
I haven't tried this but I think if you store your ShowCommentPopup flag in the HttpContext.Items collection instead of the session and then use Server.Transfer instead of Response.Redirect you should be able to achieve the desired results.
HttpContext.Items is a dictionary that can be used to store data whose lifetime is the lifetime of the request. This means a second request from a different tab or window will have a different HttpContext.Items dictionary.
Server.Transfer is somewhat like Response.Redirect in that it allows you to load a "different" URL instead of the original. However, while Reponse.Redirect initiates a new request, Server.Transfer transfers the existing request to the new page on the server.
A better explanation of the differences between Response.Redirect and Server.Transfer can be found here.
Example
bool showCommentPopup = false;
if (HttpContext.Current.Items["ShowCommentPopup"] != null)
{
showCommentPopup = (bool)HttpContext.Current.Items["ShowCommentPopup"];
}
//...
HttpContext.Current.Items["ShowCommentPopup"] = true;
You've clearly thought your solutions through! I'm guessing the problem with the Session was that they could comment on a different page than the one they logged into. You could get around this by storing the session var, not as a bool, but as the page to show it on:
var uniqueString = this.ToString() + uniquePageID;
if (Session["ShowCommentPage"].ToString() == uniqueString)
//show modal & remove session var
Now your program only "breaks" when the user visits the same object in two different windows, logs in on Window #1, and refreshes on Window #2. And it's not really breaking since they wind up commenting on the same object either way.
The reason I used uniquePageID, is cause I'm figuring you have a template page ("showObject.aspx") with arguments on which to show ("showObject.aspx?objectID=3"). In order to make sure the comment is left on the same ID, it needs to be present in uniqueString