From 7 to 8

Backend Modules in V8

Raphael Collet ([email protected])

Agenda

• Architecture of Odoo
• Module Open Academy

Architecture of Odoo

Architecture of Odoo

• Three-tier client/server/database
• Web client in Javascript
• Server and backend modules in Python
  • MVC framework

Module Open Academy

The Module

• Manage courses, sessions, and subscriptions
• Learn
  • Structure of a module
  • Definition of data models
  • Definition of views and menus

Structure of a Module

An Odoo module is

* a python module (data models), with
* a manifest file,
* XML and CSV data files (base data, views, menus),
* frontend resources (Javascript, CSS).

The Open Academy Module

The manifest file __odoo__.py::

{
    'name': 'Open Academy',
    'version': '1.0',
    'category': 'Tools',
    'summary': 'Courses, Sessions, Subscriptions',
    'description': "...",
    'depends' : ['base'],
    'data' : ['view/menu.xml'],
    'images': [],
    'demo': [],
    'application': True,
}

The Course Model

A model and its fields are defined in a Python class::

from odoo import Model, fields

class Course(Model):
    _name = 'openacademy.course'

    name = fields.Char(string='Title', required=True)
    description = fields.Text()

The Menu as XML data

.. code-block:: xml

<?xml version="1.0" encoding="UTF-8"?>
<openerp>
    <data>

        <menuitem name="Open Academy" id="menu_root" sequence="110"/>

        <menuitem name="General" id="menu_general" parent="menu_root"/>

        <record model="ir.actions.act_window" id="action_courses">
            <field name="name">Courses</field>
            <field name="res_model">openacademy.course</field>
            <field name="view_mode">tree,form</field>
        </record>

        <menuitem name="Courses" id="menu_courses" parent="menu_general"
            sequence="1" action="action_courses"/>
    </data>
</openerp>

Let's add a Form View

.. code-block:: xml

<record model="ir.ui.view" id="course_form">
    <field name="name">course form view</field>
    <field name="model">openacademy.course</field>
    <field name="arch" type="xml">

        <form string="Course" version="7.0">
            <sheet>
                <h1>
                    <field name="name" placeholder="Course Title"/>
                </h1>
                <notebook>
                    <page string="Description">
                        <field name="description"/>
                    </page>
                </notebook>
            </sheet>
        </form>

    </field>
</record>

The Session Model

.. code::

class Session(Model):
    _name = 'openacademy.session'

    name = fields.Char(required=True)
    start_date = fields.Date()
    duration = fields.Integer(help="Duration in days")
    seats = fields.Integer(string="Number of Seats")

Relational Fields

Let us link sessions to courses and instructors::

class Session(Model):
    _name = 'openacademy.session'

    ...

    course = fields.Many2one('openacademy.course', required=True)
    instructor = fields.Many2one('res.partner')

.. nextslide::

Let us back-link courses and sessions::

class Course(Model):
    _name = 'openacademy.course'

    ...

    responsible = fields.Many2one('res.users')
    sessions = fields.One2many('openacademy.session', 'course')

.. nextslide::

Let us link sessions to partners for attendee subscription::

class Session(Model):
    _name = 'openacademy.session'

    ...

    attendees = fields.Many2many('res.partner')

Computed Fields

The value of those fields is computed::

class Session(Model):
    _name = 'openacademy.session'

    ...

    taken_seats = fields.Float(compute='_compute_taken_seats')

    @api.one
    @api.depends('attendees', 'seats')
    def _compute_taken_seats(self):
        if self.seats:
            self.taken_seats = 100.0 * len(self.attendees) / self.seats
        else:
            self.taken_seats = 0.0

About self

Model instances are recordsets.

A recordset is an hybrid concept:

* collection of records
* record

.. code::

for session in self:
    print session.name
    print session.course.name

assert self.name == self[0].name

Feedback with "Onchange" Methods

Modify form values when some field is filled in::

class Session(Model):
    _name = 'openacademy.session'

    ...

    @api.onchange('course')
    def _onchange_course(self):
        if not self.name:
            self.name = self.course.name

Default Values

Specify the initial value to use in a form::

class Session(Model):
    _name = 'openacademy.session'

    ...

    active = fields.Boolean(default=True)
    start_date = fields.Date(default=fields.Date.today)

    ...

Model Constraints

Prevent bad data::

from odoo.exceptions import Warning

class Session(Model):
    _name = 'openacademy.session'

    ...

    @api.one
    @api.constrains('instructor', 'attendees')
    def _check_instructor(self):
        if self.instructor in self.attendees:
            raise Warning("Instructor of session '%s' "
                "cannot attend its own session" % self.name)

More Stuff

• Extend existing models
• Many view types
• Workflows
• Reports
• Security
• Translations

Backend Modules in V8

Conclusion

• Modules have a simple structure
• Model definition intuitive and efficient
  • uses Python standards (decorators, descriptors)
  • recordsets provide support for "batch" processing
  • many model hooks (default values, constraints, computed fields)