HiddenField value modified by javascript is not posted back - javascript

This is weird, but I've been using this method all over my code: I have dropdown lists that I populate client-side, using callbacks and because of this I'm unable to access their selected values from code behind and using a hidden field to store selected value in it. I had no problem retrieving the hidden field's value on postback, but all of a sudden it stopped working and is always blank, even when the value on client side is present.
Any thoughts?
P.S. I'm not setting or resetting hidden fields on postback.

Okay, if someone wonders what's wrong: it seems there's something related to jQuery.
The thing is that DropDownLists and the hidden field, along with the button that causes postback are inside a jQuery UI dialog that is initiated on page load without opening and appended to the form. Besides this dialog i'm initializin another one and also appending to the form, but for some reason the first appended dialog exibits the weird behavior when postback works, but hidden field does not retain the value. If i don't append the second dialog to the form, everything works as expected. Can't really tell what might appending the second dialog be doing that is causing this weird behavior.
P.S if i reverse the order in which those two dialog boxes are appended, it works just fine... Weird!

Using .NET?
When the values are added dynamically the backend has no clue. You need to use Request.Form to get the values posted back just like oldschool ASP days.

Related

Over-shadowing label when pre-populating value to form

I'm using Materialized CSS and it works very well for me. However when I added more dynamic behaviour to my app, for example when I'm pre-populating form with values and appending them to the layout, here is the photo of that:
That happens only when I preset the value to form on/prior to page load (because my form html is generated by server side).
However if I were to click into the quantity field then quantity would go back to its place and it would stay there.
How do I make it so that it stays up even when I pre-populate the form value? Is there a class I need to add to it (label or input) or JavaScript or something that I can put out there.
If you want to pre-fill text inputs, use Materialize.updateTextField(); as the docs says

Strange javascript/jquery issue

Hopefully someone can help me here.
I have a page that displays a list of users in a modal popup. This page can be accessed in two ways, one way you choose Unapproved users and it will open the page, the other way you choose user accounts which will open a popup asking if you have any search criteria such as name, once you have finished there you search and it brings up the page of users.
I have a button on the form to clear any filters. When i run it on the Unapproved users page, it clears the box fine, however if i do it on the form from the other way the code will not empty the textbox and when i try an alert it shows no data. Where as the alert works on the Unapproved route!
Here is the jquery that i am using:
clear: function () {
//reset filters//
$('.usersFilterList li').remove();
$('.userFilterSelect option').show();
$('#UserFilter_SearchTermIncluded').attr('value', ''); // This line doesn't seem to work properly
alert($('#UserFilter_SearchTermIncluded').attr('value'));
//hide filter options
MSG.showNHide('', '#usersFilterBox');
//reset modal control buttons
$('#usersButSaveFilter,#usersButClearFilter').hide();
$('#usersButFilter').fadeIn();
usersFilter.refresh(0);
}
Can anyone see if i am doing anything stupid? As i say, it is exactly the same form called from the same MVC action just with the other popup in between.
Apologies if this is confusing, I cannot post anymore code i am afraid. I can assure you that the ID of the textbox is correct though.
Any advice here would be much appreciated as I have been staring at it for hours now...
Cheers,
Gareth
If i right click the second option and run in new tab and run that first pop up as a full page the code will then work! So the problem appears to be that there are two popups.
SOLVED
I found a work around of my own, thanks for all your help.
I simply assigned a class and searched for any items with that class and cleared it like so:
$('.jq-clearme').val('');
I will close this when i can. I am not allowed yet due to my rep being too low.
To change the value of an element (or to retrieve it), accessing the attribute is the wrong way to go - it's not synchronized in both directions. What you want is the property. While also exposed through .prop('value'[, newvalue]) the correct way to get/set it with jQuery is .val([newvalue]).
To clear the element's value use the following:
$('#UserFilter_SearchTermIncluded').val('');
To retrieve/show it, use
alert($('#UserFilter_SearchTermIncluded').val());
You should use val() to get/set the value of the input.
Use without a parameter to get the value:
$('#UserFilter_SearchTermIncluded').val();
And with a paramater set the value, in this case set it to nothing:
$('#UserFilter_SearchTermIncluded').val('');
Is there an ajax call involved which might be loading the Javascript you posted twice and hence when called the second time (after the ajax call) it finds a conflict?
As mentioned by others best to use .val('') to set a value and .val() to get the value. Check in firebug if there are any Javascript errors.
I found a work around of my own, thanks for all your help.
I simply assigned a class and searched for any items with that class and cleared it like so:
$('.jq-clearme').val('');
I will close this when i can. I am not allowed yet due to my rep being too low.

javascript form submitting to wrong target second time

I have a form I am submitting with form.submit() to a hidden iframe. I then take the result and process the data.
If the result fails (validation errors) then I display an error in a div tag.
The problem I have is that if you press the submit button again the form submits to a new tab.
I tried form.reset(); // just resets the form.
I have tried resetting the target of the form to the hidden iframe again but that doesn't seem to work either.
I tried this a long time back.
The trick was to set the target of the form to hidden iframe using html and not JS. What I mean is, you should do:
formContainer.html("<form target='iframe_name' .... />");
However,
get_form_by_id.setAttribute("target","iframe_name")
didn't provide the desired result.
(There shouldn't be a reason for it, however speaking from experience, I faced this issue when designing an IE compatible website and this was the solution that worked).

Cannot access the value of the selected item of a disabled drop down, in action class (struts 2)

On a Jsp page I have some select elements which were disabled after a value was selected (Disabled them in javascript). Now when the form is submitted, I can not access those selected values in the action class.
I know for sure that this is caused by the select elements being disabled because, when I tried the same without making them disabled, it worked fine.
Now I don't understand why is this so. I thought maybe I should enable them before the form is submitted, but it does not seem a good idea.
I faced this problem while implementing this : Creating struts 2 forms dynamically on jsp using java script .
(You can find the code there. Although I don't think you will need the code, because it is clear where the problem is.)
Here I am able to access the values of text fields but I can not access the values of select elements.
I asked this question separately because I thought this is a different topic.
Thanks!!
Disabled fields by W3 specifications will not get posted on the server side so this issue is not related to the Struts2 but in generic an HTML way to go
Disabled controls
i am not sure why you want to use disabled control for your form.things can be done using readOnly attribute or use hidden fields
You can set them in hidden field through java script and pass it to action

jQuery: issue with live events, a form and the back button

I have build a quite complex widget which contains "some kind of
form". It has a form tag, but I'm loading a lot of stuff in there via
Ajax etc. Cannot explain it in detail, and the code is too long to
paste in here.
Now, in a "live('click', function()" I use for one of the form fields,
I'm writing a couple of values into hidden fields of another form.
That works fine, as I can see them in the generated code. But if I
leave the page and then hit the back button, the values are gone.
If I write some values into those fields outside the live click
function though, they are still there when I leave the page and come
back using the back button.
But I need to write the values into the hidden fields out of the live
click function (I'm inserting values from fields of my form into
them).
I don't know what causes this and wasn't able to find a workaround yet
(even though I tried a lot).
Any ideas?
Thanks!
Have a look at the jquery history plugin (http://plugins.jquery.com/project/history)
Usually what happens is that browser remembers what you have entered into a form (even if you don't submit it) so that when you hit back button, it populates all the visible fields for you.
It seems it's not the case with hidden fields. There's a workaround though.
Every time one of your hidden fields is changed, you can add #part to your url (eg. www.mysite.com/users#userId,groupId,...).
When the page is loaded again (via back button for example), it will contain the #part. Parse it as a string to determine how to populate hidden fields and populate them.
Review the history plugin for jQuery to see how to read the #part.http://plugins.jquery.com/files/jquery.history.js_0.txt
Use CSS to hide the input instead of the input type.
<input type="text" id="foo" name="foo" style="display: none;" />
instead of
<input type="hidden" id="foo" name="foo" />
I tripped over the same issue and this seems to resolve it.

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