Hi Måns!
First; I think
justingale.com is where I found a lot of the critical info for this.
(BTW, In the process of building the contact form for TWaddle, I also found a few googledocs-for-teachers applications for this that might be of value for you as a teacher: here are some:
link1,
link2,
link3 )
Ok, if your question needs the steps before the "justingale" info;
I assume you've found the tiddler
$:/_TWaddle/Buttons/Comment . This is part of the viewtoolbar (i.e tagged $:/tags/ViewToolbar ). This is premise so that the title can be sent along to the googledoc.
The iframe is surrounded by a varswidget that takes the current tiddler title;
<$vars tid={{!!title}}>
<iframe src=<<googtid>> scrolling="no" frameborder="1px" overflow="hidden" width="550px" height="500px" >Loading iframe...</iframe>
</$vars>
...and the <<googtid>> macro, uses this "tid" as an argument into a cell in the spreadsheet:
Just to make sure theres no misunderstanding: In the resulting spreadsheet you get a new row for each posting people make, also if it is regarding the same tiddler. This is preferable, and it is merely a matter of sorting by name in the "tiddler title" column in the spreadsheet to get all comments regarding a specific tiddler.
The particular url syntax is, I assume, part of Googles API. The justingale link should lead you to an explanation for this.
Hope this is of help. Tell me how it works out.
<:-)