eiru_salon_spa/models/project_service.py

# -*- coding: utf-8 -*-
from openerp import models, fields, api, tools
from openerp.exceptions import ValidationError, except_orm, Warning, RedirectWarning

class ProjectService(models.Model):
    _name = 'project.service'

    name = fields.Char('Nombre') 
    sequence = fields.Integer(string='Sequence')
    image_medium = fields.Binary('Binary File')
    active = fields.Boolean('Activo')
    color = fields.Integer('Color Index')

    project_service_task_ids = fields.One2many(
        'project.service.task',
        'project_id',
    )
    project_service_task_count = fields.Integer(
        string='Contador de trabajos',
        compute='_get_project_service_task_count',
    )

    _defaults = {
        'active': 1,
    }

    @api.multi
    def unlink(self):
        for project in self:
            if len(project.project_service_task_ids) > 0:
                raise Warning('No puedes borrar un proyecto que tiene tareas')
        return super(ProjectService, self).unlink()

    @api.one
    @api.depends('project_service_task_ids')
    def _get_project_service_task_count(self):
        self.project_service_task_count = len(self.project_service_task_ids)