insertRow madness

[Hal Burgiss]

Hi, and help for a novice trying to get some data dynamically into
tables. I did a small proof of concept page which works fine in IE6 and
Mozilla. Using code such as this:

tbody = document.getEle mentById('tb');
thead = document.getEle mentById('heade r');

tr = thead.insertRow (-1);
td = document.create Element('th');
tr.appendChild( td);

/* start building data here */

[...]

All is well. I paste essentially the same code with subsequent
modifications below this point into a more complex page and it breaks on
IE6 with a 'null is null and not an object' error, regardless of how I
play with it. It breaks at the insertRow statement. I've tried going to
createElement in lieu of insertRow and it breaks in exactly the same
place. No matter what I change. I've tried inserting into the table
itself, thead, and tbody. All get a null object. And yet the original
page works fine, with nearly identical code! Ouch, my brain hurts.

The test pages are:

http://burgiss.net/work/table.html (works fine)
http://burgiss.net/work/pricelist.html (breaks)

Any help is appreciated.

--
Hal Burgiss

[RobG]

Re: insertRow madness

Hal Burgiss wrote:[color=blue]
> Hi, and help for a novice trying to get some data dynamically into
> tables. I did a small proof of concept page which works fine in IE6 and
> Mozilla. Using code such as this:
>
> tbody = document.getEle mentById('tb');
> thead = document.getEle mentById('heade r');
>
> tr = thead.insertRow (-1);
> td = document.create Element('th');
> tr.appendChild( td);
>
> /* start building data here */
>
> [...]
>
> All is well. I paste essentially the same code with subsequent
> modifications below this point into a more complex page and it breaks on
> IE6 with a 'null is null and not an object' error, regardless of how I
> play with it. It breaks at the insertRow statement. I've tried going to
> createElement in lieu of insertRow and it breaks in exactly the same
> place. No matter what I change. I've tried inserting into the table
> itself, thead, and tbody. All get a null object. And yet the original
> page works fine, with nearly identical code! Ouch, my brain hurts.
>
> The test pages are:
>
> http://burgiss.net/work/table.html (works fine)
> http://burgiss.net/work/pricelist.html (breaks)
>
> Any help is appreciated.
>[/color]

Most probably because you have already created thead as a global
variable in drawTable() before makeTable() is called.

Make it local in drawTable() and see what happens.



--
Rob

[Hal Burgiss]

Re: insertRow madness

On Mon, 09 Jan 2006 04:14:09 GMT, RobG <rgqld@iinet.ne t.au> wrote:
[color=blue][color=green]
>> Any help is appreciated.[/color][/color]
[color=blue]
> Most probably because you have already created thead as a global
> variable in drawTable() before makeTable() is called.[/color]

Wow, thanks. Looked at it for two hours but did not see that.
[color=blue]
> Make it local in drawTable() and see what happens.[/color]

Sadly, making it a local has not helped yet. I even took out
drawTable() completely and get that error just with makeTable().

Thanks for the help!!

--
Hal Burgiss

[RobG]

Re: insertRow madness

Hal Burgiss wrote:[color=blue]
> On Mon, 09 Jan 2006 04:14:09 GMT, RobG <rgqld@iinet.ne t.au> wrote:
>
>[color=green][color=darkred]
>>>Any help is appreciated.[/color][/color]
>
>[color=green]
>>Most probably because you have already created thead as a global
>>variable in drawTable() before makeTable() is called.[/color]
>
>
> Wow, thanks. Looked at it for two hours but did not see that.
>
>[color=green]
>>Make it local in drawTable() and see what happens.[/color]
>
>
> Sadly, making it a local has not helped yet. I even took out
> drawTable() completely and get that error just with makeTable().[/color]

Ok, cop this. Comment out the line:

document.getEle mentById('title ').innerHTML = my_title;


and see what happens... :-x



--
Rob

[RobG]

Re: insertRow madness

RobG wrote:
[...]
[color=blue]
>
> Ok, cop this. Comment out the line:
>
> document.getEle mentById('title ').innerHTML = my_title;
>
>
> and see what happens... :-x
>[/color]

From the MSDN innerHTML reference:

"The property is read/write for all objects except the following, for
which it is read-only: COL, COLGROUP, FRAMESET, HTML, STYLE, TABLE,
TBODY, TFOOT, THEAD, TITLE, TR. The property has no default value.

...

"You can change the value of the title element using the
document.title property."

<URL:http://msdn.microsoft. com/library/default.asp?url =/workshop/author/dhtml/reference/dhtml_reference _entry.asp>



Somewhat bizarre side-effect, eh? ;-p



--
Rob

[Hal Burgiss]

Re: insertRow madness

On Mon, 09 Jan 2006 05:18:21 GMT, RobG <rgqld@iinet.ne t.au> wrote:[color=blue]
>
> Ok, cop this. Comment out the line:
>
> document.getEle mentById('title ').innerHTML = my_title;
>
>
> and see what happens... :-x[/color]

Hey, wow that was it!!! Amazing. Mucho gracias! I feel a tremendous
weight has been lifted :0

--
Hal Burgiss

[Hal Burgiss]

Re: insertRow madness

On Mon, 09 Jan 2006 05:24:28 GMT, RobG <rgqld@iinet.ne t.au> wrote:[color=blue]
>
> "You can change the value of the title element using the
> document.title property."
>
> Somewhat bizarre side-effect, eh? ;-p[/color]

Amen. Now just how did you figure that out?

--
Hal Burgiss

[Hal Burgiss]

Re: insertRow madness

On 9 Jan 2006 06:49:52 -0500, Hal Burgiss <hal@burgiss.ne t> wrote:[color=blue]
>
> Hey, wow that was it!!! Amazing. Mucho gracias! I feel a tremendous
> weight has been lifted :0[/color]

Even stranger (at least to me), "title" was the id of an h2 element.
Chaning the id to "foo" has the same effect. Wierd. Thanks again though.

--
Hal Burgiss

[RobG]

Re: insertRow madness

Hal Burgiss wrote:[color=blue]
> On Mon, 09 Jan 2006 05:24:28 GMT, RobG <rgqld@iinet.ne t.au> wrote:
>[color=green]
>> "You can change the value of the title element using the
>> document.title property."
>>
>>Somewhat bizarre side-effect, eh? ;-p[/color]
>
>
> Amen. Now just how did you figure that out?
>[/color]

thead was an object, but totally bereft of properties. I kept
checking to see when it finally had an ID property.

Remove slabs of stuff until properties appear, then add stuff back
slowly until they're gone again. First I removed all the lines of
makeTable() after the offending line, then the content of the init()
function which gave a clue - fortunately there were only about 6 lines!

No wonder prototyping/RAD is the only way to do web applications -
write a line of code, test everything. Write another line of code,
test everything...


--
Rob