How to use a filter for many2one filed on form?

Question

I have 3 fields which in my module page.2 are for product categories and 1 for product. The categories fields consist of different categories. Now I want to add filter so that what ever category I set in the field, only those product should list in the products field . It is a type of sorting or filtering. I dont have much idea of using filter in such a scenerio under form view. Here is my code.py:

class deg_form(osv.osv):
    _name = "deg.form"
    _columns = {
         'categ1':fields.many2one('product.category','Parent Category'),
         'categ2':fields.many2one('product.category','Child Category'),
         'my_products':fields.many2one('product.product','Products',size=64),

            }


deg_form()

and here is its xml:

<record id="mywin_form_view" model="ir.ui.view">
            <field name="name">mywin.form</field>
            <field name="model">deg.form</field>          
            <field eval="7" name="priority"/>
            <field name="arch" type="xml">
                <form string="FORM DATA" version="7.0">

                     <h1>
                       <label for="categ1" string="Parent category"/>
                           <field name="categ1" />
                     </h1>

                     <h1>
                       <label for="categ2" string="Child category"/>
                           <field name="categ2" />
                     </h1>
<newline/>

                     <h1> 
                       <label for="my_products" string="Products" domain = "[('categ1','=',True)]"/> 
                           <field name="my_products"/> 
                     </h1>


                 <button name="show_product" string="SHOW PRODUCT" type="action"/>
                 </form>
             </field>
    </record>

please help me fix this

Answer 1

Use domain filter in py or xml as

domain = "[('categ_id','=',categ1)]"

Or

Overwrite def search method of product.product and pass categ field as parameter

def search(self, cr, uid, args, offset=0, limit=None, order=None, context=None, count=False):
    if context is None:
        context = {}
    if context and context.get('search_default_categ_id', False):
        args.append((('categ_id', '=', context['categ_id'])))
    return super(product_product, self).search(cr, uid, args, offset=offset, limit=limit, order=order, context=context,count=count)

For Parent child relation of product category use this domain filter in py or xml (categ2)

domain = "[('parent_id','=',categ1)]"