How to use a global variable to update a selection field with Odoo 10?

Question

Hi is it possible to have a global variable which gets updated based on 'onchange' and assign the same to a selection field?

variable = []

class a:
    @api.onchange('some_other_filed')
    def function1(self):
        global variable
        variable = #something based on some other filed

    test = fields.Selection(variable)

Will this onchange reflect in selection field. All I get is empty list in selection field.

Answer 1

Using global variables is not recommended. You can use a persistent field on the ir.config_parameter table if you want to make it always available from anywhere in Odoo. You can see the stored configuration parameters on Settings > Technical > Parameters > System Parameters.

You can set the value of the parameter like this:

self.env['ir.config_parameter'].set_param('use_journal_setting', True)

And get some other value like this:

location = self.env['ir.config_parameter'].get_param(
    'ir_attachment.location'
)

You can also update the selection field directly with some value, or you can use the parameter to update it.

@api.onchange('field_name')
def onchange_field_name(self):
    self.test = self.env['ir.config_parameter'].get_param('parameter_name')

Note: If you need many of these global variables, consider creating your own parameters table.