jQuery Forum

I thought I'd undertake the endeavour of translating into jquery the
neat little "click-n-drag checkboxes" functionality of cross-
browser.com's X-library. This functionality allows for multiple
checkbox selection or de-selection by simply clicking on one of them
and then dragging the mouse over the others.
I began mentioning this in another post, but I figured that perhaps a
new post with the right title would be better. Rather than re-post all
the code though, here's a reference to the message where the full code
of both the X-library functions and my attempted translation of them
is posted:
http://groups.google.com/group/jquery-en/msg/0f38d747d97cf701
I doesn't quite seem to work though, none of my checkboxes are getting
selected either on click or on drag. Any javascript - jquery experts
have any ideas on what needs to be perfected?
When I run it in Internet Explorer, the debugger gives me this
message:
"Cannnot assign to a function result"
and it refers to line 56, which should be the one that sets the
selection:
48 $("td.mychkbox").each(
49 function(){
50 $(this).bind(
51 "mouseover",
52 function(){
53 if (gCheckedValue != null){
54 var eccomi = this;
55 var eccoti = $(eccomi).find("input:checkbox");
56* $(eccoti).attr("checked") = gCheckedValue;
57 }
58 });
59 });

Could someone please help me work out this bit of code, it's driving
me crazy!
I've read here and there that "this" changes value according to its
level of enclosure, it can refer for example to an object that
triggers an event but then if used in callback it can refer to the
jquery function itself...
Well here's my bit of code that I'm working on.
I have a number of table cells that have checkbox inputs in them; I
have given to the table cells a "mychkbox" class.
I have another checkbox in a table cell, which when clicked selects
all of the others. I have put this checkbox in the "allchecked"
variable to simplify the code.
I want the mousedown event of all the "mychkbox" table cells to
trigger some events when "allchecked" is NOT checked.
$("td.mychkbox").each( // select all the cells
with class "mychkbox"
function(){
$(this).bind( // apply the
mousedown event to each one of these
"mousedown", // (and here $(this) is
correctly referring to those cells
function(){ // because the
mousedown event is triggering correctly
if (allchecked.attr("checked")==false){// only if allchecked
is NOT checked, do such n such
// Now what I need to do here is get the "checked" state of the
checkbox which is a child of the table cell.
// If I do:
var itsme = this; // this seems to get the
table cell, in fact:
alert(itsme); // gives me [object
HtmlTableCellElement]
// I can't seem to access any of the attributes of the table cell let
alone the children.
alert(itsme.name); // gives "undefined"
// or:
var itsyou = itsme.attr("name");
alert(itsyou); // gives no results,
it actually stops everything from working
// or:
var itsyou = eccomi.find("input:checkbox");
alert(eccoti); // gives no results,
it actually stops everything from working
}
});
});
Hmmm... I'm stumped, I can't access the child checkbox, much less the
child checkboxes "checked" value.
Anyone have any ideas?

Ok let's see if this post works... The last couple tries didn't!
I was reading through this year-old thread which I found googling
since I'm doing something similar, perhaps someone could give me a
couple tips.
Here is the page with the example I'm dealing with:
http://johnrdorazio.altervista.org/SitoFlatnukePersonale/index.php?mod=04_Mia_programmazione/04_Tabelle_con_Jquery
Clicking on the checkboxes, two rows should appear (which were hidden
from the beginning) in which more information can be inserted (that
otherwise would not be necessary).
The only problem is, it seems to work only in Internet Explorer. In
Firefox the rows wind up appearing at the bottom of the table, and
every time you un-click and re-click some mysterious space begins
accumulating. Not only, but the cells of the two appearing rows don't
line up with the cells of all the other rows of the table, the seem to
want to line up with only the first column which really opens up wide
that first column shifting the whole table over to the right. Google
Chrome presents a similar problem, only the appearing rows don't wind
up at the bottom of the table. They stay where they're supposed to be,
but the cells still don't line up and they shift the whole table, and
un-click re-click still creates that mysterious gap.
At first I was applying JQuery directly to the rows that were
involved, then reading this thread I tried creating different "tbody"
sections and applying the JQuery to those sections, but the problems
remain. Perhaps it could be a problem of parent-child relationships?
I'm not sure how those work though, if anyone has any thoughts I would
be very grateful.
Here is my code:
<script type="text/javascript" src="/SitoFlatnukePersonale/include/
javascripts/jquery.js"></script>
<script type="text/javascript">
$(document).ready(function(){
$(".showhidesection").hide();
$("#pastoralcounsel").click(function(){
if ($("#pastoralcounsel:checked").val()!=null)
{
$("#represents").show("fast");
}
else
{
$("#represents").hide("fast");
}
});
$("#i_am_a_catechist").click(function(){
if ($("#i_am_a_catechist:checked").val()!=null)
{
$("#catechizes").show("fast");
}
else
{
$("#catechizes").hide("fast");
}
});
$("#volunteer").click(function(){
if ($("#volunteer:checked").val()!=null)
{
$("#volunteers").show("fast");
}
else
{
$("#volunteers").hide("fast");
}
});
});
</script>
<table class="sample">
<tbody class="alwaysshowsection">
<tr><td><input type="checkbox" name="pastoralcounsel"
id="pastoralcounsel"></td><td><label for="pastoralcounsel">Cons.
Pastorale</label></td></tr>
</tbody>
<tbody id="represents" class="showhidesection">
<tr><td>---</td><td><label for="i_represent"> -> rappresenta:</label></
td></tr>
<tr><td>...</td><td><input type="text" name="i_represent"
id="i_represent"></td></tr>
</tbody>
<tbody class="alwayshowsection">
<tr><td><input type="checkbox" name="i_am_a_catechist"
id="i_am_a_catechist"></td><td><label
for="i_am_a_catechist">Catechista</label></td></tr>
</tbody>
<tbody id="catechizes" class="showhidesection">
<tr><td>---</td><td><label for="i_catechize_this_group"> -> del
gruppo:</label></td></tr>
<tr><td>...</td><td><select name="i_catechize_this_group"
id="i_catechize_this_group"><option>I^ Anno Comunioni</option></
select></td></tr>
</tbody>
<tbody class="alwaysshowsection">
<tr><td><input type="checkbox" name="volunteer" id="volunteer"></
td><td><label for="volunteer">Volontario parrocchiale</label></td></
tr>
</tbody>
<tbody id="volunteers" class="showhidesection">>
<tr><td>---</td><td><label for="voluntaryservice"> -> servizio:</
label></td></tr>
<tr><td>...</td><td><input type="text" name="voluntaryservice"
id="voluntaryservice" /></td></tr>
</tbody>
</table>