You can do self references --
see http://web2py.com/book/default/chapter/06#Self-Reference-and-Aliases.
You would need to do Field('div', 'reference div').
On Saturday, October 15, 2011 9:05:05 AM UTC-4, Erwin Pass wrote:
>
> Hi there,
>
> I saw on stackoverflow that you prefer questions here :)
>
> I need to display a form for a nested table structure. This means that
> a record of a table might have a reference to another record of that
> table. I have no idea how to model something like this using DAL and
> SQLFORM. I guess it isn't even possible but you might have another
> idea to implementi this.
>
> To illustrate my problem think about some xml or html structure where
> a node of a certain type can contain nodes of other types as well as
> nodes of the same type.
>
> <div id='some_div_record'>
> <ul id='root_ul_ref'>
> <li id='first_li_ref'>text</li>
> ...
> <li id='nth_li_ref'>nth text</li>
> <ul>
> <div id='another_div_record'>
> ...
> </div>
> </div>
>
> A div block might contain other div blocks. This seems not to be
> possible to model using DAL:
>
> db.define_table('div',
> Field('text', type='string'),
> Field('ul', type=db.ul),
> Field('div', db.div))
>
> This attempt results in some KeyError: 'div', probably caused because
> db.div is about to defined but referenced before it could be
> constructed fully.
>
> The second part of the problem I'm facing might be an even tougher
> one. Because I not only need to store references to _one_ another
> record of the same table but to a unknown number of such records. (It
> is not known how many divs the user choses to nest within...)
>
> I guess this requires another table like db.div_to_div which contains
> the references (ids) but then I'm lost on ideas how to connect
> implement the view which connects all this and enables the user to
> enter his data.
