Fantastic! Thanks. When I asked a couple of years ago that wasn't pointed
out, so I assumed that there wasn't a standard way. This is perfect.
Ian
On Wednesday, February 12, 2014 5:43:40 PM UTC-5, Anthony wrote:
>
> To get the actual ID field of the referenced table, you can also do:
>
> db.mytable.myfield.referent
>
> and to get the table:
>
> db.mytable.myfield.referent.table
>
> and to get the table name:
>
> db.mytable.myfield.referent.tablename
>
> Anthony
>
> On Wednesday, February 12, 2014 5:40:00 PM UTC-5, Anthony wrote:
>>
>> A reference field has type "reference tablename", so you can do:
>>
>> db.mytable.myfield.type.split(' ')[-1]
>>
>> Anthony
>>
>> On Wednesday, February 12, 2014 3:58:58 PM UTC-5, Ian W. Scott wrote:
>>>
>>> I've been working for a while on a very flexible (and so increasingly
>>> complex) multiple-select widget that can be re-populated from the db via
>>> ajax (without submitting the form). One think I had to do was figure out
>>> how to get the name of the table referenced by the field using my widget.
>>> With some help from the folks here I found this solution:
>>>
>>> referencetable = myfield.requires[0].ktable
>>>
>>> I'm starting to realize, though, that this is fragile. I know it's doing
>>> an end-run around the DAL api (accessing implementation details instead of
>>> the stable api). I also found recently that this was broken by the
>>> IS_EMPTY_OR validator. For the moment I'm hacking a solution by doing this:
>>>
>>> try:
>>> referencetable = myfield.requires[0].ktable
>>> except AttributeError:
>>> # because IS_EMPTY_OR doesn't have a property .ktable,
>>> # it's on the second, wrapped validator
>>> referencetable = myfield.requires[0].other.ktable
>>>
>>> But I'm digging myself a deeper hole. Now I'm using a second
>>> implementation detail (the "other" instance variable of IS_EMPTY_OR) and my
>>> widget is that much more prone to being broken by future releases.
>>>
>>> So I'm wondering whether
>>>
>>> (a) there's a way to access this data via the api that I'm just missing;
>>> or
>>> (b) this is reason to add access to the referenced table to the api.
>>>
>>> This could be as simple as adding a get_reference_table() method to the
>>> validators that (for the time being) draws on the instance variables I've
>>> been using.
>>>
>>> # in IS_EMPTY_OR
>>> def get_reference_table(self):
>>> return self.other.ktable
>>>
>>> # in IS_IN_DB
>>> def get_reference_table(self):
>>> return self.ktable
>>>
>>> I'm not sure, though, whether the validator is the best place for that
>>> method. Should it be a method of Field instead? (That is, if others see a
>>> need for this at all.)
>>>
>>> Cheers,
>>>
>>> Ian
>>>
>>
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