Hello. Before start some code:

class ExampleModelItem(models.Model):
    _name = "example.model.item"
    partner_id = fields.Many2one(comodel_name='res.partner')
    lines = fields.Many2many(comodel_name='sale.order.line')

    @api.onchange("partner_id")
    def _compute_sale_lines(self):
        ctx_obj = self._context['reglas']

class ExampleModel(models.Model):
    _name = "example.model"
    reglas = fields.One2many(comodel_name='example.model.item', inverse_name='...', string="...")
    lines = fields.Many2many(comodel_name='sale.order.line')

The view in "example.model" looks like :

    <field name="reglas" context="{'reglas': reglas}">
        <tree>...</tree>
        <form>...</form>
    </field>

As you can see in the view we set the field in the context, we get the value to ctx_obj variable in the _compute function.

This ctx_obj have a list of the old o2m structure [(0, False, {...}), (1, 1, {...}), (4, 3, False), ..., (type, id, data)]

The problem i facing is, how can i know in the compute method if the record is one of the records in the ctx_obj? Or even better, wich one. When self.id exists its easy, because i can find that id in the ctx_obj. But when self.id is a Newid object, the ctx_obj will be a False. Is there a way to acknowledge is the newid is already in the context object or not??

Thank you in advance