todo-model-extensions

name	todo-model-extensions
description	Extend todo task sqlmodel, add priority tags due_date recurring reminder fields to Task model. Always preserves existing fields (id, user_id, title, description, completed, created_at, updated_at) and maintains backward compatibility. Use when modifying Task model with new fields like priority, tags, due_date, recurrence, and reminders.

Todo Model Extensions

Overview

This skill provides guidance for extending the existing Task SQLModel with additional fields while maintaining backward compatibility and preserving existing functionality. It helps developers add priority, tags, due_date, recurrence, and reminder fields to the Task model following SQLModel best practices.

Extension Guidelines

When extending the Task model, always preserve existing fields and follow these patterns:

Required Existing Fields (Preserve These)

• id: Primary key (auto-generated)
• user_id: Foreign key with index for user isolation
• title: Task title (string)
• description: Optional task description
• completed: Boolean indicating completion status
• created_at: Timestamp for creation time
• updated_at: Timestamp for last update

New Extension Fields

When adding new fields, use these exact specifications:

• priority: Optional[Literal["high", "medium", "low"]] = None (with index)
• tags: List[str] = Field(default_factory=list, sa_column=Column(JSON))
• due_date: Optional[datetime] = Field(default=None, index=True)
• recurrence_rule: Optional[str] = None (RRULE string for recurrence)
• reminder_enabled: bool = False (whether to enable reminders)

SQLModel Best Practices

• Use Field() for defaults and indexes: Field(default=None, index=True)
• Use sa_column=Column(JSON) for complex types like lists
• Import JSON from sqlalchemy for JSON column type
• Import Literal from typing_extensions for literal types
• Always include proper type hints
• Add indexes to frequently queried fields (due_date, priority)

Example Implementation

from sqlmodel import Field, SQLModel
from sqlalchemy import Column, JSON
from typing import List, Optional
from typing_extensions import Literal
from datetime import datetime

class Task(SQLModel, table=True):
    id: int = Field(primary_key=True)
    user_id: int = Field(index=True)  # Preserved for user isolation
    title: str  # Preserved
    description: Optional[str] = None  # Preserved
    completed: bool = False  # Preserved
    created_at: datetime  # Preserved
    updated_at: datetime  # Preserved

    # New extension fields
    priority: Optional[Literal["high", "medium", "low"]] = Field(default=None, index=True)
    tags: List[str] = Field(default_factory=list, sa_column=Column(JSON))
    due_date: Optional[datetime] = Field(default=None, index=True)
    recurrence_rule: Optional[str] = None  # RRULE string
    reminder_enabled: bool = False

    # Relationship back-reference if needed
    user: "User" = Relationship(back_populates="tasks")

Query Patterns

When querying extended Task models, always include user_id filter for security:

# Correct query pattern with user isolation
tasks = session.exec(
    select(Task).where(
        Task.user_id == current_user.id,  # Always include user_id filter
        Task.priority == "high"
    ).order_by(Task.due_date)
).all()

# For due date queries
overdue_tasks = session.exec(
    select(Task).where(
        Task.user_id == current_user.id,  # Always include user_id filter
        Task.due_date < datetime.now(),
        Task.completed == False
    )
).all()

Migration Considerations

• Add new columns with appropriate defaults to maintain backward compatibility
• Create indexes on new indexed fields after adding the columns
• Test existing functionality still works after extensions
• Update any existing Task-related services to handle new fields appropriately