Build a Library Management Module – Odoo Capstone Project

🏋️ Practical Exercise

Create the library.book and library.member models.
Add a loan model linking them.
Build views and a menu.
Add access rights.
Add a "return book" action.

🔥 Challenge Exercise

Build a complete Library module from scratch: models for books, members, and loans (with relations), views and menus, access rights, and a method to borrow and return a book with availability checks. Explain how the pieces (models, views, security, logic) fit together into a working module.

What you'll build:

Three models: library.book, library.member, library.loan
Form, list, kanban, and search views
Access rights and record rules
Computed fields: loan count, overdue status, fine amount
A wizard: "Return Book" dialog with batch processing
Customer portal: member's loan history
Scheduled action: mark overdue loans automatically

Project Overview

The library module tracks books and member loan history. The requirements:

Librarians manage books, members, and loans from the backend
Members can view their active and past loans via a portal page at /my/loans
Overdue loans (past due date) are automatically marked by a daily cron job
A "Return Book" wizard allows processing multiple returns at once

Step 1: Module Structure

Bash

library_management/
├── __init__.py
├── __manifest__.py
├── models/
│   ├── __init__.py
│   ├── library_book.py
│   ├── library_member.py
│   └── library_loan.py
├── views/
│   ├── library_book_views.xml
│   ├── library_member_views.xml
│   ├── library_loan_views.xml
│   └── library_menus.xml
├── security/
│   ├── ir.model.access.csv
│   └── library_security.xml
├── wizards/
│   ├── __init__.py
│   ├── return_book_wizard.py
│   └── return_book_wizard_views.xml
├── controllers/
│   ├── __init__.py
│   └── portal.py
├── data/
│   └── library_cron.xml
└── templates/
    └── portal_my_loans.xml

Step 2: Models

Python

# models/library_loan.py
from odoo import models, fields, api
from odoo.exceptions import ValidationError
from datetime import date

class LibraryLoan(models.Model):
    _name = 'library.loan'
    _inherit = ['portal.mixin', 'mail.thread']
    _description = 'Library Loan'
    _order = 'loan_date desc'

    member_id = fields.Many2one('res.partner', string='Member', required=True)
    book_id = fields.Many2one('library.book', string='Book', required=True)
    loan_date = fields.Date(string='Loan Date', default=fields.Date.today)
    due_date = fields.Date(string='Due Date', required=True)
    return_date = fields.Date(string='Return Date')
    state = fields.Selection([
        ('active', 'Active'),
        ('returned', 'Returned'),
        ('overdue', 'Overdue'),
    ], default='active', tracking=True)

    days_overdue = fields.Integer(
        string='Days Overdue',
        compute='_compute_days_overdue',
    )
    fine_amount = fields.Float(
        string='Fine (€)',
        compute='_compute_fine_amount',
        store=True,
    )

    @api.depends('due_date', 'return_date', 'state')
    def _compute_days_overdue(self):
        today = date.today()
        for loan in self:
            end = loan.return_date or today
            if loan.due_date and end > loan.due_date:
                loan.days_overdue = (end - loan.due_date).days
            else:
                loan.days_overdue = 0

    @api.depends('days_overdue')
    def _compute_fine_amount(self):
        rate = 0.50  # €0.50 per day overdue
        for loan in self:
            loan.fine_amount = loan.days_overdue * rate

    def _compute_access_url(self):
        for loan in self:
            loan.access_url = f'/my/loans/{loan.id}'

    @api.constrains('due_date', 'loan_date')
    def _check_due_date(self):
        for loan in self:
            if loan.due_date and loan.loan_date:
                if loan.due_date < loan.loan_date:
                    raise ValidationError(
                        'Due date must be after the loan date.'
                    )

Step 3: Return Book Wizard

Python

# wizards/return_book_wizard.py
from odoo import models, fields, api
from datetime import date

class ReturnBookWizard(models.TransientModel):
    _name = 'library.return.wizard'
    _description = 'Return Book Wizard'

    loan_ids = fields.Many2many(
        'library.loan',
        string='Loans to Return',
        domain=[('state', 'in', ['active', 'overdue'])],
    )
    return_date = fields.Date(
        string='Return Date',
        default=fields.Date.today,
        required=True,
    )

    def action_return(self):
        self.loan_ids.write({
            'state': 'returned',
            'return_date': self.return_date,
        })
        for loan in self.loan_ids:
            loan.book_id.available_copies += 1
        return {'type': 'ir.actions.act_window_close'}

Step 4: Scheduled Action

XML

<!-- data/library_cron.xml -->
<record id="ir_cron_mark_overdue_loans" model="ir.cron">
  <field name="name">Library: Mark Overdue Loans</field>
  <field name="model_id" ref="model_library_loan"/>
  <field name="state">code</field>
  <field name="code">model.mark_overdue_loans()</field>
  <field name="interval_number">1</field>
  <field name="interval_type">days</field>
  <field name="numbercall">-1</field>
  <field name="active">True</field>
</record>

Python

# In LibraryLoan model
@api.model
def mark_overdue_loans(self):
    from datetime import date
    overdue = self.search([
        ('state', '=', 'active'),
        ('due_date', '<', date.today()),
    ])
    overdue.write({'state': 'overdue'})

Step 5: Portal Integration

Add the portal controller (extend CustomerPortal) and a QWeb template. See the Portal Controllers and Portal Templates lessons for the full patterns to follow.

Key steps for the portal page:

Add portal.mixin to library.loan (already done above)
Add access rights for base.group_portal in ir.model.access.csv
Add record rule: portal users see only their own loans
Write LibraryPortal(CustomerPortal) with portal_my_loans and portal_loan_detail routes
Write QWeb templates inheriting portal.portal_layout

Extension challenges:

Add a library.category model and filter books by category in the list view
Add an email notification when a loan becomes overdue (using mail.template)
Extend the portal to allow members to request a loan via a form
Add a Kanban view for loans grouped by state
Add a dashboard with a count of active loans, overdue loans, and total fines

Interview Questions

What models would a library app need?
How do you model book–member loans?
How do you enforce that a book cannot be double-borrowed?
What security does the module need?
How do you wire a button to a Python method?

FAQ

Why use TransientModel for the return wizard instead of a regular form? +

The return wizard only needs to exist for the duration of the user's action — the data (return date, condition, note) is not a permanent business record. TransientModel records are auto-cleaned by Odoo's vacuum job, so you don't accumulate wizard records in the database over time.

What is portal.mixin and why is it added to library.loan? +

portal.mixin adds _compute_access_url() and an access token field, giving each loan record a unique portal URL. The controller uses _document_check_access() (also from the mixin) to verify the logged-in user is the loan's member before rendering the page.

How does the overdue cron job avoid updating already-returned loans? +

The cron domain filters [('state', '=', 'active'), ('due_date', '<', fields.Date.today())] — only active loans past their due date are updated to overdue. Returned or lost loans are already in a terminal state and are excluded by the domain.

🏋️ Practical Exercise

🔥 Challenge Exercise

Project Overview

Step 1: Module Structure

Step 2: Models

Step 3: Return Book Wizard

Step 4: Scheduled Action

Step 5: Portal Integration

Interview Questions

Related Topics

Related Topics

FAQ