I am currently working on a site for an auto dealer and ran into a bit of a snag when I started trying to ad pagination to the inventory page.
The inventory page has 5 search options type, make, year, model and trim. They are all drop downs and they are all populated by a live feed, changing the options autopostback the page and the inventory/nav are updated accordingly.
Everything was working great until I went to add pagination to the page. The pagination works fine for what it is, if there are more then 15 results it adds a numbered nav to the page that allows the user to jump pages.
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The problem is when they do jump pages all of the search options revert to there original settings, and when the page loads its pulling in every car again instead of what the user searched for. I can't really figure out what the issues is, I expect the state is getting lost when the user clicks the link even though it is to the same page. I tried using sessions but it seems to have muddied it up, does anyone have any suggestions for a fix?
If you require the code I can link it, I warn you though it is a pretty large amount of code and I don't think you could find much in it, but who knows.
Try using a LinkButton control with an OnClick event. Do whatever you are doing when you test for the "page=4" querystring parameter in the OnClick event. You are losing state because the a regular html anchor tag causes the page to load as if it were the first time you visited and ViewState is blown away - Page.IsPostback is false.
If you don't want to use a sever side control, you could always pass the search parameters in the query string.
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If you do it this way, please be sure to sanitize your inputs before you pass them back to the database.
Related
I'm trying to describe it in as few steps as possible:
I have Page1.aspx with lot of controls, and Preview and Save button among those. I also have Page2.aspx that is the redirection target of a Preview Button click.
Since I need all the controls selections from Page1 to draw a preview on Page2 the redirection is done with setting Preview's PostBackUrl.
I also must have preview shown on a new tab or window so I used onClientClick="aspnetForm.target='_blank'" for Preview button definition.
Save button-click callback, after storing data to a database does redirection to some Page0.aspx (initial list of reports - the subject of the code)
Preview button works fine - a preview renders in a new tab, but when I go to the old tab and click on Save, I see from debugger, that firstly Page2.aspx(?) and secondly Page1.aspx are loaded. Then all the data is stored in the db, but though Page0 redirection is executed Page1.aspx stays loaded in the browser.
I have no idea what processes are behind this. Could one who knows give me an insight? Or if you consider my approach impossible to implement give some idea how to do the same?
If it's of importance, everything on the Page1 is located in an update panel.
Thank you very much for replying
In ASP.NET there are basically zero (0) circumstances in which you will ever send form data from one page to another. Although what exactly you are trying to accomplish is vague, you can consider some of the following:
Isolate unique operations/systems to a single page. If you have something like a User Profile, don't have three different aspx pages; just use a single page for the user or admin to manage that data / functions. Postback events are your friend.
Understand the difference between ViewState and traditional form data. I'm guessing that if you're trying to post form data from one page to another, you probably don't understand the point of ViewState. Using a single page to maintain temporary data that the user is currently working with is a great use for ViewState. If you want the data to appear on another page then you need to consider the data from the previous page as final and thus should be saved to a database or some other medium.
These are just some general guidelines because there is no exact answer to your problem without saying something generic like "You're doing it wrong." I would recommend starting by never again trying to post form data from one aspx page to another.
I thought this would be a trivial feature, but I have lost a fair bit of hair trying to figure it out. I have a jquery mobile web page with a select menu. Users click an item in the drop down list, then later click on a link and navigate to another page. Users then click the back button. The desired result is that the selected item remains selected. Right now, the selection is lost, and it defaults to the first element in the list again.
Things I've tried:
1) Use an asp.net dropdownlist with autopostback. This preserves the selected option, but then I get a page flicker because the entire page is posted back.
2) Wrap above asp.net dropdownlist in an updatepanel. This preserves, doesn't flicker, but it wipes out the jquery mobile styling. Also tried some suggested workarounds with firing a jquery create event, but couldn't get anything working.
3) Write cookies on the select change event in javascript, and read them in the asp page_load event. However, page_load is not called when the back button is clicked, so this had no effect.
4) Tried creating a jquery ajax request to a web page method, but the method must be static and therefore I can't get it to modify the page.
Any other ideas? Is it just me or should this indeed be a problem that's been solved a million times?
As an FYI, I am a newbie at web programming, so please spell it out if you have an answer :) (come from a c++/database background).
Thanks!
Turns out even the date scroller could not survive a back button in some cases. For example if the user navigates to another site, and then uses the back button to come back to my jquery mobile site, all my javascript dom manipulations are lost. The solution is non-trivial. I store everything I need to maintain state of a page using html 5 local storage. On the jqm show page event, I detect if all my global variables have been wiped clean, and if so, reload state from local storage. Works perfectly, but it is quite an implementation task. And of course, if local storage is not supported by underlying browser, it all falls to pieces.
want to have search functionality as on this website
http://www.carwale.com/new/search.aspx#budget=6&budget=8&fuel=2
here whenever the user filters search(checks any checkbox), it updates results accordingly,
that can be understood as an ajax filter.
But at the same time, the query string also reflects for the change,
which helps the user to bookmark the filter search for later reference.
changing it through asp.net/javascript may cause the page to reload..
any hint or suggestions on implementing the same would be really helpful..
This can be done with the help of 3 things together
1) as #Aristos said, checkboxes with Auto Postback enabled
2) Ajax control toolkit Modalpopup, which gets fired automatically on every async postback (http://weblogs.asp.net/ruslan/pages/ajax-update-progress-updateprogress-in-ajax-modal-popup-modalpopupextender.aspx or http://mattberseth.com/blog/2007/07/modalpopup_as_an_ajax_progress.html)
3) History Points (http://msdn.microsoft.com/en-us/library/cc488548.aspx)
This can be done completely without the use of jQuery, if you dont want to use it.
-- For the first part, he have a set of check boxes list with autopostback.
In every post back the list is updated base on the selected check box.
All is simple until now, the cool is that is have a nice interactive interface (made with javascript and jQuery).
-- About the second part, how its change the url so can be bookmark with out reload the page. The trick here is that is place the parameters after the anchor # eg:
/new/search.aspx#budget=2
Using the anchor # the page is not reload and stay as it is. So when some one click on the check boxes, via javascript is also update the url, but only what is after the # so the page stay as is with out fully reload.
Now the parameters after the # can not read on code behind but only via javascript.
So when you have bookmark this page and you go direct to eg /new/search.aspx#budget=2 the javascript reads what is after the # and translate it to commands, check the appropriate checkboxes, and ask for refresh the content. All that can be done only via javascript.
I see that is use the jQuery history plugin as helper with this schema.
http://archive.plugins.jquery.com/project/history
The same trick with parameters after # is done from amazon, when you navigate on catalog, from page to page.
-- One more clever trick that is done is that is open a full page wait, so the user can not interact with the page until the page is ready again. If it not do that, and the user make very fast two clicks on the check boxes, then this can cause a full page post back on updatepanel and this can lose the previous settings.
I have a page in asp.net by clicking on the grid in the page it takes me to the detail page,on this page i have a back button (not browser back) by clicking on the button it takes me again to the search page.
i want to see the page with changes which i have made before coming to the detail page,also i want to disable back button of browser.
i dont want to use session variable or viewstate variable.
is there any property for this scenario.
yours sincerely
Talha khan
You can't disable the browser back button. End of story. Sorry.
What changes are you making to the grid, where is it getting it's data from? You could use a cookie to store the previous pages' state if you don't want to use session or viewstate.
If the the amount of data you need to track is relatively small (in your case this would probably be a search query) you can use query string to pass the state to the detail page (which can be later passed back to the search page).
You can also use browser cookies to persist the state but I wouldn't do that (at least because they're not designed for this kind of interaction).
-- Pavel
There are several ways to solve this.
The first that comes to mind is to change the page to AJAX. AJAX would not force a page jump forward, hence there will be nowhere to go back to.
The second way is to have a check on the previouis page, for example set "Session("if_search_go_here") = Request.Url.PathAndQuery" and unset it at the right place. If this is set then the search page will just forward you to the detils page again.
probably more. :)
I am a little confused and making it alot more complicated than this needs to be! Here is what I have...
A view which displays a drop down of US States. When the user chooses a state it loads a list of data from a database and returns the results (populates the View Model) and the View renders the information.
What I wanted to do was have have the dropdown trigger an Ajax event which performs the data load, but also wanted it to depreciate if the user didn't have Javascript enabled. How would I go about rendering the view with AND without javascript / ajax?
Hope that makes sense. Thanks for your help.
You can't re-populate a drop-down without jscript. You can do a page-reload with a new drop-down though, although the logic to determine which to use is javascript unfortunately. (Not to mention triggering the re-load of the page on click)
No Javascript support though? That seems kind of out of date, most people run javascript-enabled browsers these days. As for paranoia freaks with javascript turned off, a <noscript> block to tell them to get over it may be appropriate.
To do this with ajax, read this article about cascade dropdowns by Stephen Walther.
To do this without ajax, you could put your first dropdown in a form with a button visible only when javascript is disabled (hide this with javascript for that) wich gets to some action (in another window, maybe) wich returns the second dropdown populated according to the element selected on the first (on the first window, if you have 2 - you could know this url using a viewstate variable).