add revert deleted object mixin

[yaserrahimi]

added revert deleted object by ading a mixin

Description

When using django-simple-history, deleted objects are preserved in historical records, but there was no built-in way to restore them. Administrators had to manually recreate deleted objects or write custom code to restore them. This mixin solves that problem by providing a user-friendly interface for object restoration.

Key Features

1. Restore Button

• Displays a visual "🔄 Restore" button in the admin list view for deletion records
• Shows "✓ Already Restored" for objects that have been recovered
• Provides instant, one-click restoration for individual objects

2. Bulk Admin Action

• "Revert selected deleted objects" action for batch restoration
• Process multiple deleted objects simultaneously
• Intelligent filtering to only restore valid deletion records

3. Safety & Validation

• Duplicate Prevention: Checks if object already exists before restoring
• Deletion Record Validation: Only processes records with history_type == "-"
• Error Handling: Gracefully handles restoration failures with clear error messages
• ID Preservation: Restores objects with their original primary keys

4. User Feedback

• Clear success messages with object details and IDs
• Warnings for already-restored or non-deletion records
• Error messages for failed restorations
• Detailed count summaries for bulk operations

How It Works

1. Detection: Identifies deletion records in historical data (history_type == "-")
2. Validation: Verifies the record is a deletion and object doesn't already exist
3. Restoration: Recreates the object with exact field values from historical record
4. ID Preservation: Maintains original primary key for referential integrity
5. History Tracking: Creates new history record documenting the restoration

Technical Implementation

Core Components

• revert_button(obj): Renders restore button in admin list display
• handle_revert_from_button(request): Processes single-object restoration
• revert_deleted_object(request, queryset): Handles bulk restoration action
• get_actions(request): Registers the revert action with Django admin
• changelist_view(request, extra_context): Integrates button clicks with admin

Data Integrity

• Preserves all field values from the deletion point
• Maintains original primary key (ID)
• Properly handles foreign key relationships
• Creates new historical record for the restoration
• Supports all Django field types

Related Issue

Motivation and Context

recovering deleted objects in admin site

How Has This Been Tested?

i add my test in project tests folder

Screenshots (if appropriate):

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• [ x] New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• [x ] I have run the pre-commit run command to format and lint.
• [x ] My change requires a change to the documentation.
• [x ] I have updated the documentation accordingly.
• [x ] I have read the CONTRIBUTING document.
• [x ] I have added tests to cover my changes.
• [x ] I have added my name and/or github handle to AUTHORS.rst
• [x ] I have added my change to CHANGES.rst
• [x ] All new and existing tests passed.