# 🚀 Odoo 19 Custom Module Development Guidelines

This document summarizes the coding standards, strict constraints, and Odoo 19 specific architectural changes discovered and enforced across the `student_ERP_Metatron` modules.

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## 1. 🖥️ User Interface & Views
- **Tree Views Deprecated**: The `<tree>` XML tag and `tree` view mode have been completely replaced by `<list>`. 
  - **Action Window Definitions**: You must define `view_mode` as `list,form` instead of `tree,form`.
  - **View Architectures**: Use `<list>` tags instead of `<tree>` when defining list view layouts.

## 2. 🗄️ Database & ORM Constraints
- **SQL Constraints Deprecated**: The `_sql_constraints` list attribute is no longer supported.
  - **Odoo 19 Standard**: Define SQL constraints using `models.Constraint` at the class level.
  - **Example**: 
    ```python
    _code_unique = models.Constraint('unique(code)', 'The Code must be unique!')
    ```
- **Strict Validation**: Models like `education.student` have strict database-level `NotNullViolation` constraints for academic fields (`batch_id`, `semester_id`, `section_id`). These must always be populated when creating records, especially during automated testing.

## 3. 🔐 Security & Access Rights
- **Group Fields**: When assigning groups to `res.users` or defining access, note that the underlying model for groups uses `res.groups.privilege`. 
- **Field Name Changes**: When creating or writing to `res.users`, the relational field for groups has been renamed from `groups_id` to `group_ids`.
- **Portal Controllers**: Portal users lack access to standard internal models (like `ir.sequence`). Sequence generation triggered from portal controllers (e.g., creating a library issue) must be executed using `.sudo()`.

## 4. 🌐 Web Controllers & Translation
- **Translation Function `_()`**: The standard translation function `_()` attempts to retrieve the user's language by accessing `self.env`.
  - **The Issue**: In HTTP controllers, `self` refers to the Controller instance, not an ORM Model. Calling `_("Error")` inside a controller (e.g., within a `raise AccessError(...)`) throws `AttributeError: 'NoneType' object has no attribute 'uid'`.
  - **The Solution**: Avoid wrapping error strings in `_()` within controllers unless explicitly using `request.env._()`.

## 5. 🧪 Automated Testing
- **Buffered ORM Operations**: Odoo 19 heavily buffers database inserts and updates. 
- **Testing Constraints**: When testing database-level exceptions (like `UniqueViolation`), the error will not trigger immediately upon calling `.create()`. You must call `self.env.flush_all()` within the `assertRaises` block to force the ORM to flush the transaction to PostgreSQL and trigger the exception.
- **Example**:
  ```python
  with self.assertRaises(Exception):
      self.env['my.model'].create({'unique_field': 'duplicate'})
      self.env.flush_all()  # Crucial for triggering the DB error!
  ```
- **Constraint Exceptions**: Odoo 19 often raises raw database exceptions (`Exception` / `psycopg2` errors) rather than cleanly wrapped `ValidationError` objects for database-level violations. Adjust assertions accordingly.