Vendor Bill Editable Totals

Overview

This Odoo 17 module enables accountants to directly edit the tax excluded (price_subtotal) and tax included (price_total) amounts on vendor bill invoice lines. When these fields are modified, the system automatically recalculates the unit price (price_unit) to maintain exact decimal accuracy with the user-inputted amounts.

This is particularly useful when entering vendor bills where the supplier invoice shows total amounts that don't divide evenly, or when you need to match exact amounts without manually calculating unit prices.

Features

• ✅ Direct editing of tax excluded amounts - Modify price_subtotal directly on vendor bill lines
• ✅ Direct editing of tax included amounts - Modify price_total directly on vendor bill lines
• ✅ Automatic unit price recalculation - System calculates price_unit to match your entered totals
• ✅ Decimal precision accuracy - Maintains exact amounts within configured decimal precision
• ✅ Multiple tax support - Correctly handles lines with multiple taxes
• ✅ Credit note support - Works with negative values for credit notes and adjustments
• ✅ Edge case handling - Graceful handling of zero quantities, no taxes, and other edge cases
• ✅ Seamless integration - Works with standard Odoo vendor bill workflows

Installation

1. Copy the vendor_bill_editable_totals folder to your Odoo addons directory
2. Update the apps list: Go to Apps → Click Update Apps List
3. Search for "Vendor Bill Editable Totals"
4. Click Install

Configuration

No configuration is required. The module works out of the box after installation.

The module respects Odoo's existing decimal precision settings:

• Navigate to Settings → Technical → Database Structure → Decimal Accuracy
• The "Product Price" precision setting controls the rounding of calculated unit prices

Usage

Editing Tax Excluded Amount (price_subtotal)

1. Navigate to Accounting → Vendors → Bills
2. Create a new vendor bill or open an existing draft bill
3. Add or select an invoice line
4. Click on the Subtotal field (price_subtotal) in the invoice line
5. Enter the desired tax excluded amount
6. Press Enter or click outside the field
7. The Unit Price will automatically recalculate to match your entered amount

Example:

Quantity: 3
You enter Subtotal: 100.00
System calculates Unit Price: 33.33
Recomputed Subtotal: 99.99 (or 100.00 depending on precision)

Editing Tax Included Amount (price_total)

1. Navigate to Accounting → Vendors → Bills
2. Create a new vendor bill or open an existing draft bill
3. Add or select an invoice line with taxes configured
4. Click on the Total field (price_total) in the invoice line
5. Enter the desired tax included amount
6. Press Enter or click outside the field
7. The Unit Price will automatically recalculate, accounting for taxes

Example:

Quantity: 5
Tax: 10%
You enter Total: 550.00
System calculates:
  - Subtotal: 500.00 (550.00 / 1.10)
  - Unit Price: 100.00 (500.00 / 5)
Recomputed Total: 550.00

Use Cases

Use Case 1: Matching Supplier Invoice Totals

Scenario: Your supplier invoice shows a line total of €127.50 for 7 items, but the unit price doesn't divide evenly.

Solution:

1. Create vendor bill line with quantity: 7
2. Click on the Subtotal field
3. Enter: 127.50
4. System calculates unit price: 18.21 (rounded)
5. The line total will match the supplier invoice exactly

Use Case 2: Entering Tax-Included Amounts

Scenario: Your supplier invoice shows a total of $1,234.56 including 15% tax for 10 items.

Solution:

1. Create vendor bill line with quantity: 10 and 15% tax
2. Click on the Total field
3. Enter: 1234.56
4. System calculates:
   • Subtotal: 1073.53
   • Unit price: 107.35
5. The line total including tax will match exactly

Use Case 3: Credit Notes

Scenario: You need to create a credit note for a returned item worth -€50.00.

Solution:

1. Create vendor credit note (refund)
2. Add line with quantity: 1
3. Click on the Subtotal field
4. Enter: -50.00
5. System calculates unit price: -50.00
6. Negative values are handled correctly

Technical Details

How It Works

The module extends the account.move.line model with two @api.onchange methods:

1. _onchange_price_subtotal() - Triggered when price_subtotal is modified

   • Validates quantity is not zero
   • Calculates: price_unit = price_subtotal / quantity
   • Applies decimal precision rounding

2. _onchange_price_total() - Triggered when price_total is modified

   • Validates quantity is not zero
   • Calculates tax factor from configured taxes
   • Derives: price_subtotal = price_total / (1 + tax_rate)
   • Calculates: price_unit = price_subtotal / quantity
   • Applies decimal precision rounding

View Modifications

The module inherits the vendor bill form view (account.view_move_form) and makes the following changes:

• Sets readonly="0" for price_subtotal field
• Sets readonly="0" for price_total field
• Adds conditional readonly based on:
  • Document state (only editable in 'draft' state)
  • Document type (only editable for vendor bills and refunds)

Supported Document Types

The editable fields are available for:

• Vendor Bills (move_type='in_invoice')
• Vendor Credit Notes (move_type='in_refund')

The fields remain readonly for:

• Customer Invoices
• Customer Credit Notes
• Journal Entries
• Posted documents (state != 'draft')

Limitations

• Fields are only editable in draft state (standard Odoo behavior)
• Only works for vendor bills and vendor credit notes
• Requires quantity to be set before editing totals (to avoid division by zero)
• Minor rounding differences may occur due to decimal precision limits

Error Handling

Division by Zero

If you attempt to edit price_subtotal or price_total when quantity is zero, you'll see an error:

Cannot calculate unit price: quantity must be greater than zero

Solution: Set the quantity to a non-zero value before editing the total fields.

Precision Rounding

Due to decimal precision limits, there may be minor differences (typically < 0.01) between your entered amount and the recomputed amount. This is normal and expected behavior.

Example:

You enter: 100.00
Quantity: 3
Calculated unit price: 33.333333...
Rounded unit price: 33.33 (2 decimal places)
Recomputed subtotal: 99.99

Testing

The module includes comprehensive test coverage:

Property-Based Tests

• Price subtotal calculation accuracy
• Quantity preservation during modifications
• Round-trip accuracy for price_subtotal
• Round-trip accuracy for price_total with taxes
• Decimal precision compliance

Unit Tests

• Zero quantity error handling
• Negative values (credit notes)
• No taxes scenario
• Single tax calculation
• Multiple taxes calculation
• View configuration

Integration Tests

• Full workflow: create → modify → save → verify
• Compatibility with standard Odoo validations

To run tests:

# Run all property tests
python customaddons/vendor_bill_editable_totals/tests/run_property_test.py
python customaddons/vendor_bill_editable_totals/tests/run_price_total_test.py
python customaddons/vendor_bill_editable_totals/tests/run_decimal_precision_test.py

# Run unit tests
python customaddons/vendor_bill_editable_totals/tests/run_edge_case_tests.py
python customaddons/vendor_bill_editable_totals/tests/run_view_tests.py

# Run integration tests
python customaddons/vendor_bill_editable_totals/tests/run_integration_tests.py

Compatibility

• Odoo Version: 17.0
• Python Version: 3.10+
• Database: PostgreSQL 12+
• License: LGPL-3

Dependencies

• account - Odoo core accounting module

Support

For issues, questions, or contributions, please contact your system administrator or the module maintainer.

Changelog

Version 17.0.1.0.0

• Initial release
• Direct editing of price_subtotal on vendor bill lines
• Direct editing of price_total on vendor bill lines
• Automatic unit price recalculation
• Support for multiple taxes
• Support for credit notes
• Comprehensive test coverage

Credits

Author: Your Company

Contributors:

• Development Team

License

This module is licensed under LGPL-3.

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Note: This module follows Odoo development best practices and is designed to integrate seamlessly with existing Odoo workflows. It does not modify core Odoo functionality and can be safely installed and uninstalled without affecting other modules.