A Step-by-Step Guide to Download Sale Invoices from Odoo 17 Using Python Flask and XML-RPC

1. Importing necessary libraries

```python

from flask import Flask, request, jsonify, send_file

import xmlrpc.client

import requests

```

- Flask: A web framework used for building web applications in Python.

- xmlrpc.client: A library for making XML-RPC calls.

- requests: A library for making HTTP requests.

2. Setting up Odoo connection details

```python

url = 'https://your_odoo_instance_url.com'

db = 'your_odoo_database'

username = 'your_odoo_username'

password = 'your_odoo_password'

```

- url: URL of your Odoo instance.

- db: Database name in Odoo.

- username: Username for authentication.

- password: Password for authentication.

3. Authenticating with Odoo

```python

session_url = f'{url}web/session/authenticate'

data = {

    'jsonrpc': '2.0',

    'method': 'call',

    'params': {

        "service": "common",

        "method": "login",

        'db': db,

        'login': username,

        'password': password,

    }

}

session_response = requests.post(session_url, json=data)

session_data = session_response.json()

session_id = session_response.cookies['session_id']

```

- The code initiates a session with the Odoo instance by sending authentication data in a JSON format.

- It then extracts the session ID from the response cookies.

4. Authenticating using XML-RPC

```python

common = xmlrpc.client.ServerProxy('{}/xmlrpc/2/common'.format(url))

uid = common.authenticate(db, username, password, {})

```

- Uses XML-RPC to authenticate with the Odoo server and obtain a user ID (uid).

5. Accessing Odoo models

```python

models = xmlrpc.client.ServerProxy('{}/xmlrpc/2/object'.format(url))

```

- Creates an XML-RPC client object to interact with Odoo models.

6. Downloading the PDF file

```python

invoice = models.execute_kw(db, uid, password, 'account.move', 'read', [21566], {'fields': ['name']})

pdf_file = models.execute_kw(db, uid, password, 'account.move.send', 'action_send_and_print', [4,[21566]])

```

- Retrieves invoice details and PDF file URL using XML-RPC.

7. Downloading the PDF content

```python

headers = {'Cookie': f'session_id={session_id}'}

download_url = f'{url}{pdf_file["url"]}'

response = requests.get(download_url, headers=headers)

pdf_content = response.content

```

- Constructs headers with the session ID and makes a GET request to download the PDF file.

8. Saving the PDF file

```python

filename = '{}.pdf'.format(invoice[0]['name'])

with open(filename, 'wb') as f:

    f.write(pdf_content)

```

- Saves the downloaded PDF content to a file on disk.

Complete Code

```python

from flask import Flask, request, jsonify, send_file

import xmlrpc.client

import requests

# Replace these with your own Odoo connection details

url = 'https://your_odoo_instance_url.com'

db = 'your_odoo_database'

username = 'your_odoo_username'

password = 'your_odoo_password'

session_url = f'{url}web/session/authenticate'

data = {

    'jsonrpc': '2.0',

    'method': 'call',

    'params': {

        "service": "common",

        "method": "login",

        'db': db,

        'login': username,

        'password': password,

    }

}

session_response = requests.post(session_url, json=data)

session_data = session_response.json()

session_id = session_response.cookies['session_id']

common = xmlrpc.client.ServerProxy('{}/xmlrpc/2/common'.format(url))

uid = common.authenticate(db, username, password, {})

# Create a new XML-RPC client object

models = xmlrpc.client.ServerProxy('{}/xmlrpc/2/object'.format(url))

# Download the PDF file for the first invoice in the list

invoice = models.execute_kw(db, uid, password, 'account.move', 'read', [21566], {'fields': ['name']})

pdf_file = models.execute_kw(db, uid, password, 'account.move.send', 'action_send_and_print', [4,[21566]])

# Call the URL and send authorization

# Set the cookie value in the request headers

headers = {'Cookie': f'session_id={session_id}'}

# Call the URL with the specified cookie value

download_url = f'{url}{pdf_file["url"]}'

response = requests.get(download_url, headers=headers)

pdf_content = response.content

# Save the PDF file to disk

filename = '{}.pdf'.format(invoice[0]['name'])

with open(filename, 'wb') as f:

    f.write(pdf_content)

```

This code should authenticate with your Odoo instance, retrieve the specified invoice, download its associated PDF, and save it locally. Make sure to replace the placeholder values with your actual Odoo connection details.