Controllers - BackAnt

In BackAnt, the route layer is the controller. Its only job is to receive an HTTP request, call the service, and return a JSON response. All logic lives in the service.

The controller pattern

A correct BackAnt route function is always short:

from flask import Blueprint, jsonify, request
from services.orders_service import myOrdersService

orders_bp = Blueprint("orders", __name__, url_prefix="/orders")

@orders_bp.get("")
def get_orders():
    response = myOrdersService.get_orders()
    return jsonify(response)

@orders_bp.post("/create")
def create_order():
    data = request.get_json()
    response = myOrdersService.create_order(data)
    return jsonify(response)

The route:

Reads input from request if needed
Passes it to the service
Returns jsonify(response)

What does NOT belong in a route

# Wrong — business logic in the route
@orders_bp.post("/create")
def create_order():
    data = request.get_json()
    if not data.get("user_id"):       # ← belongs in service
        return jsonify({"error": "user_id required"}), 400
    total = sum(item["price"] for item in data["items"])  # ← belongs in service
    order = Orders(user_id=data["user_id"], total=total)  # ← belongs in repository
    db_session.add(order)             # ← belongs in repository
    db_session.commit()               # ← belongs in repository
    return jsonify(order)

Protected routes

Apply decorators directly to the route function. The @token_required decorator validates the Authorization header before the function runs:

from decorators.token_required import token_required

@orders_bp.get("")
@token_required
def get_orders():
    response = myOrdersService.get_orders()
    return jsonify(response)

See Authentication for decorator details.

Returning HTTP status codes

Pass the status code as the second argument to jsonify():

return jsonify(response), 201   # Created
return jsonify(response), 204   # No Content

For error responses, raise APIException from the service — the error handler in app.py converts it to JSON automatically. See Error Handling.

Auto-generated controller structure

When ant generate route orders runs, the generated route file looks like:

from flask import Blueprint, jsonify
from services.orders_service import myOrdersService

orders_bp = Blueprint("orders", __name__, url_prefix="/orders")

@orders_bp.get("")
def orders_route():
    response = myOrdersService.get_orders()
    return jsonify(response)

Every subsequent ant generate subroute call appends a new endpoint function to this file.

​The controller pattern

​What does NOT belong in a route

​Protected routes

​Returning HTTP status codes

​Auto-generated controller structure

The controller pattern

What does NOT belong in a route

Protected routes

Returning HTTP status codes

Auto-generated controller structure