backend-patterns

Backend Code Patterns Reference

Overview

This document provides code examples and patterns for common backend operations. Use these patterns to ensure consistency across the codebase.

Route Patterns

Standard Protected Route

from flask import Blueprint, request, jsonify
from ..utils.common_patterns import require_authenticated_user, handle_exceptions_with_logging
from ..utils.security.secure_errors import SecureErrorHandler
from app import db

my_bp = Blueprint('my', __name__, url_prefix='/api/v1/my')

@my_bp.route('/resource', methods=['GET'])
@handle_exceptions_with_logging
@require_authenticated_user
def get_resource(user):
    """Get resource for authenticated user"""
    # user is automatically provided by decorator
    resource = get_resource_for_user(user.id)
    from app.dtos.user import UserDTO
    return jsonify({
        'success': True,
        'data': UserDTO.to_response(user),
    })

Agent-Only Route

from ..utils.common_patterns import require_agent_access, handle_exceptions_with_logging

@agent_bp.route('/clients', methods=['GET'])
@handle_exceptions_with_logging
@require_agent_access
def get_clients(user):
    """Get clients for authenticated agent"""
    # user is guaranteed to be an agent
    clients = get_agent_clients(user.id)
    return jsonify({
        'success': True,
        'clients': clients
    })

Route with JSON Validation

from ..utils.common_patterns import validate_json_request, require_authenticated_user

@my_bp.route('/update', methods=['PUT'])
@validate_json_request(required_fields=['name', 'email'])
@require_authenticated_user
def update_profile(user, data):
    """Update user profile - data is automatically validated"""
    user.name = data['name']
    user.email = data['email']
    db.session.commit()
    return jsonify({'success': True})

Combined Decorator Pattern

from ..utils.common_patterns import api_route

@my_bp.route('/resource', methods=['POST'])
@api_route(require_auth=True, require_json=True, required_fields=['field1', 'field2'])
def create_resource(user, data):
    """Create resource with combined decorators"""
    # user and data are automatically provided
    resource = create_resource_for_user(user.id, data)
    from app.dtos.user import UserDTO
    return jsonify({'success': True, 'data': UserDTO.to_response(user)})