Why jQuery function returns null?

Question

I have this form:

<form action="javascript:;" class="iceFrm" enctype="application/x-www-form-urlencoded" id="frmMainMenu" method="post" onsubmit="return false;">
.....
</form>

I do not understand why this script:

<script type="text/javascript">
$(document).ready(function () {
    $("#frmMainMenu").$("#menuPopupAP").$("#menuItem0").$("#out").css('padding','0 0 0 29px');
});
</script>

says:

$("#frmMainMenu") is null

in Firebug.

UPDATE: This is the html element (from the above form) I want to change the padding on:

<span id="frmMainMenu:menuPopupAP:menuItem0:out" class="iceOutTxt iceMnuItmLabel graMenuPopupMenuItemLabel">My Applications</span>

Update 2:

I've forgot to mention that this span is within a menu, so basically it's hidden normally and displayed only when hovering on some div... Does jQuery finds it even if it's not displayed?

Do you know why?

The result of `$(...)` does not have another property `$(...)`. — pimvdb, Mar 23 '11 at 16:40
`$("#frmMainMenu").$("#menuPopupAP").$("#menuItem0").$("#out")` is not correct. What exactly are you trying to do? — gen_Eric, Mar 23 '11 at 16:40
I've updated my post, maybe the way I try to find this elements is wrong... — Cristian Boariu, Mar 23 '11 at 16:41

Alnitak · Answer 1 · 2011-03-23T16:46:28.613

2

I'm not sure exactly why you're getting the null error, but if your intent is to apply that style to those four specific elements the syntax should be:

$("#frmMainMenu, #menuPopupAP, #menuItem0, #out").css('padding','0 0 0 29px');

If (and I can't tell as we've been giving an insufficient markup sample) those four elements are successive nodes in a hierarchy (i.e. #out is a child of #menuItem is a child of #menuPopupAp is a child of #frmMainMnenu) then remove the commas between them.

EDIT colons in an id? That'll cause problems with jQuery selectors. Try using an underscore instead?

edited Mar 23 '11 at 16:46

answered Mar 23 '11 at 16:36

Alnitak

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IDs *can* contain colons, it's valid, but jQuery can't select IDs with colons like that, because the `:` is read as a selector. You need to do `[id="value"]` instead. – gen_Eric Mar 23 '11 at 16:47

score 1 · Answer 2 · edited May 23 '17 at 09:58

1

Update after your question update:

$('#frmMainMenu\3AmenuPopupAP\3AmenuItem0\3Aout').css('padding','0 0 0 29px');

You cant use the : in your selector but you can use the hexadecimal equivalent - \3A

There are few other workarounds on this SO thread.

Are your trying to search the children of frmMainMenu? try this instead:

$(document).ready(function () {
            $("#frmMainMenu").find("#menuPopupAP")
                             .find("#menuItem0")
                             .find("#out")
                             .css('padding','0 0 0 29px');
});

edited May 23 '17 at 09:58

Community

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answered Mar 23 '11 at 16:35

Geoff Appleford

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`$('#frmMainMenu:menuPopupAP:menuItem0:out')` doesn't actually work, because jQuery uses the `:` as a selector. – gen_Eric Mar 23 '11 at 16:46
@Rocket - yes, I realised that. Thanks. Have update my answer. – Geoff Appleford Mar 23 '11 at 16:52

score 0 · Answer 3 · answered Mar 23 '11 at 16:36

It's not that - it's one of the children that is null. You need to change your script to something like this

<script type="text/javascript">
 $(document).ready(function () {
            $("#frmMainMenu #menuPopupAP #menuItem0 #out").css('padding','0 0 0 29px');
        });
        </script>

score 0 · Answer 4 · answered Mar 23 '11 at 16:36

0

Surely you don't mean to use # each time (otherwise you could just use #out, but it sounds like it should be something like

$("#frmMainMenu .menuPopupAP .menuItem0 .out").css(...

answered Mar 23 '11 at 16:36

silkcom

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score 0 · Answer 5 · answered Mar 23 '11 at 16:38

0

Can you post what do you need to accomplish? from your selector, I think you are taking a hard selector approach to interact with your DOM.

answered Mar 23 '11 at 16:38

Mohammed Swillam

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score 0 · Accepted Answer · answered Mar 23 '11 at 16:41

0

$('#frmMainMenu:menuPopupAP:menuItem0:out').css('padding','0 0 0 29px');

$('span[id="frmMainMenu:menuPopupAP:menuItem0:out"]').css('padding','0 0 0 29px');

You need to use the [id="value"] syntax, because in a jQuery selector the : can be used as a selector, so it doesn't realize that the IDs can contain them.

answered Mar 23 '11 at 16:41

gen_Eric

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Well, very strange it still gives me null...please note that the above id is taken from Firebogu so basically it's the composed id of all parent components... – Cristian Boariu Mar 23 '11 at 17:00
@Cristian: What do you mean by "composed id"? – gen_Eric Mar 23 '11 at 17:48
I mean that it takes the ids of all parents and shown the results with : between ids... – Cristian Boariu Mar 23 '11 at 17:55
@Cristian: I didn't know Firebug did that. – gen_Eric Mar 23 '11 at 18:11
Thanks! Your solution worked and I also needed to replace $ with jQuery. – Cristian Boariu Mar 23 '11 at 18:37

Why jQuery function returns null?

6 Answers6