setting a default value for a field based on a m2m

brunogola · **Joined:** Wed Nov 18, 2009 8:39 pm **Posts:** 1

hi,

i have a model 'A' wich relates to a model 'B' through a o2m field 'b_id'. the A model also has an integer field 'a_field'

when I'm adding a new 'A' entry through the OpenERP interface I go to a B instance page and click "add new A'. i need to set a default value for the a_field based on the last 'A' instance related to this 'B' instance.

The problem is that I can't find how I get the 'B' instance id I'm adding these 'A' instance.

is there a way to accomplish that?

thanks

rhanke · **Joined:** Fri May 29, 2009 1:51 pm **Posts:** 16

i faced a similar problem and the way i solved it was via the context option. within the xml definition i used the context tag to store the "active_id". within the py file i created a default for the (as you call it) "a_field" and assigned the variable from the context string.

hope this will help you.

bino · **Joined:** Fri Nov 06, 2009 4:26 am **Posts:** 79

Hi Rhanke

rhanke wrote:

i faced a similar problem and the way i solved it was via the context option. within the xml definition i used the context tag to store the "active_id". within the py file i created a default for the (as you call it) "a_field" and assigned the variable from the context string.

Could you please paste your code on how you put this "context option" ?

Sincerely
-bino-

tulator · **Joined:** Thu Oct 01, 2009 4:27 pm **Posts:** 9

Hi, I also would appreciate if you could paste your code. I have no idea how to solve this problem via xml and py file.
regards
-tulator-

jfd81 · **Posted:** Sun Jul 24, 2011 11:16 pm

Hi,
Here, is what I found (this example is base on an o2m field):

In the py file:

Code:

    _defaults = {
        'a_field' : lambda self, cr, uid, context : context['a_field'] if context and 'a_field' in context else None  
    }

In the xml file (in a ir.ui.view record):

Code:

...
<field  name="o2m_field" nolabel="1" mode="tree,form" context="a_field=active_id,b_field=xxx,c_field=yyy">
...