Key Features

• Bridge Model (``product.class.attribute.line``) — Manages the relationship between classes and attributes, storing both allowed attributes and a required flag
• Strict Validation — Products assigned to a class must:
  • Use only attributes defined in that class
  • Provide values for all required attributes
• UI Enforcement — Attribute selection in product forms is restricted by the class domain filter
• Management Views — Full CRUD interface for product classes (Inventory > Configuration > Product Classes, Sales > Configuration > Product Classes)

Technical Architecture

• product.class — Main product classification model
• product.class.attribute.line — Bridge model linking classes to attributes with a required flag
• product.attribute (inherited) — Extended with reverse one-to-many to track which classes use it
• product.template (inherited) — Added class validation and computed required-attribute tracking

Table of contents

1. Create a Product Class

Navigation: Inventory → Configuration → Product Classes (or Sales → Configuration → Product Classes)

1. Click Create button
2. Enter a Product Class Name (e.g., “Chairs”)
3. In the Attributes section:
   • Click Add a line
   • Select an Attribute from the dropdown
   • Check Required if products of this class must define this attribute
   • Repeat to add more attributes
4. Click Save

Example: “Furniture” Class

2. Assign a Product to a Class

Navigation: Inventory → Products → Products

1. Create or edit a product
2. Find the Product Class field in the Attributes & Variants tab (added by this module)
3. Select the class (e.g., “Furniture”)
4. The form will now restrict Attributes to only those allowed by the class

3. Add Attribute Lines to a Classed Product

Once a class is selected, you can add attribute lines:

1. Go to the Attributes & Variants tab
2. In Attribute Lines, click Add a line
3. The Attribute field dropdown is now filtered to show only class-allowed attributes
4. Select an attribute and provide values
5. Validation will fail if:
   • You select an attribute not in the class → Error: “has attribute lines that do not belong”
   • You leave out a required attribute → Error: “is missing required attributes”

4. Remove an Attribute from a Class

Scenario: Your “Furniture” class allowed “Color” but wants to retire it.

1. Navigate to the class
2. In Attributes, find the “Color” line and delete it
3. Odoo will raise an error if products in this class still use Color
   • Fix: Remove Color from all products in the class first, then retry the class update

Workflow Example

Step 1: Set Up “Chairs” Class

• Color (required)
• Size (required)
• Leg Material (optional)

Step 2: Create a “Wooden Chair” Product

• Assign class: “Chairs”
• Add attribute “Color” = Red (satisfies required)
• Add attribute “Size” = Large (satisfies required)
• Add attribute “Leg Material” = Oak (optional, still valid)
• Save ✓ Success

Step 3: Try Invalid Assignment

• Assign class: “Chairs”
• Add attribute “Color” = Blue (satisfies required)
• Try to save without Size → Error: “is missing required attributes for the selected class ‘Chairs’: Size”
• Add Size = Medium
• Save ✓ Success

Class Attribute Line Model

The bridge model product.class.attribute.line stores:

Constraint: A class cannot configure the same attribute twice (unique on class_id + attribute_id).

Constraints & Validations

1. Class Constraint (_check_attribute_ids_used_by_products)
   • Prevents removing an attribute from a class if products still use it
   • Error: “Cannot remove attributes used in products assigned to class…”
2. Product Constraint (_check_class_attributes)
   • Ensures all attribute lines belong to the class
   • Ensures all required attributes are defined
   • Error: “Product ‘…’ has attribute lines that do not belong to the selected class ‘…’”
   • Error: “Product ‘…’ is missing required attributes for the selected class ‘…’”

Advanced: Access Control

• User (base.group_user): Can create/read/write product classes and their attributes
• System/Admin (base.group_system): Full CRUD including delete

Product class attribute lines follow the same access rules.