Hi,

You can see this type of custom dropdownlist (selection) into pricelist file of product module. It looks like below.

def _price_field_get(self, cr, uid, context=None):

mf = self.pool.get('ir.model.fields')

ids = mf.search(cr, uid, [('model','in', (('product.product'),('product.template'))), ('ttype','=','float')], context=context)

res = []

for field in mf.browse(cr, uid, ids, context=context):

res.append((field.name, field.field_description))

return res

_columns = {

"field" : fields.selection(_price_field_get, "Product Field", size=32, required=True, help="Associated field in the product form."),

}

Here 'field' is selection and its data is comes dynamic from the method "_price_field_get".

Hope you will get custom dropdownlist.

Best Regards,

Ankit H Gandhi.

This post has years but I had the same question. May this way can help for new implementations

type_tax_use = fields.Selection(
        [
            ('sale', 'Sale'),
	​	​	​('purchase', 'Purchase'),
	​	​], default='purchase', string="Tax Type")

move_type = fields.Selection(
        [
            ('in_invoice', 'Purchase Invoice'),
            ('in_refund', 'Purchase Credit Note'),
            ('out_invoice', 'Sale Invoice'),
            ('out_refund', 'Sale Credit Note'),
        ], default='in_invoice', string="Invoice Type"
)

sale_move_type = fields.Selection(
        [
            ('out_invoice', 'Sale Invoice'),
            ('out_refund', 'Sale Credit Note'),
        ], default='out_invoice', string="Sale Invoice Type"
)
purchase_move_type = fields.Selection(
        [
            ('in_invoice', 'Purchase Invoice'),
            ('in_refund', 'Purchase Credit Note'),
        ], default='in_invoice', string="Purchase Invoice Type"
)

@api.onchange('sale_move_type','purchase_move_type')
def _onchange_ref_move_type(self):
    if self.type_tax_use == 'sale':
        self.move_type = self.sale_move_type
    elif self.type_tax_use == 'purchase':
        self.move_type = self.purchase_move_type

In the xml you show the desired field according to type_tax_use with domain scope

there are 3 pattern for that to be approached

https://dev.to/kerbrose/dynamic-selection-list-in-odoo-for-selection-fields-16h8

Make your field a many2one field

'my_field': fields.many2one('my.table', ... ),

put the 'selection' widget

<field name="my_field" widget="selection" ...>

in an 'on_change' method set the appropriate domain for your selection field and return this domain , this will change the values appearing in your dropdown selection list

def onchange_for_my_field(self, cr, uid, ids, param1, param2, ... , context=None):
     ...
       return {'domain' : 
             {'my_field':
             [('field1','=',val1),('field2','=',val2),... ] }
     }

where field1 and field2 , ... are fields in the table 'my.table' that could be used to filter the result.

Hope this solution is useful