Build a GraphQL API with Python, Flask and Ariadne

Setup

• Set virtualenv and install dependencies

$ virtualenv todo_api_env
$ source todo_api_env/bin/activate
(todo_api_env)$ pip3 install -r requirements.txt

• Create some Todos

python3
>>> from main import db
>>> db.create_all()
>>>
>>> from datetime import datetime
>>> from api.models import Todo
>>> today = datetime.today().date()
>>> todo = Todo(description="Run a marathon", due_date=today, completed=False)
>>> todo.to_dict()
{'id': None, 'completed': False, 'description': 'Run a marathon', 'due_date': '2021-08-22'}
>>> db.session.add(todo)
>>> db.session.commit()
>>> exit()

• Run application

export FLASK_APP=main.py
flask run

Open GraphQl Playground http://127.0.0.1:5000/graphql

Test

• fetchAllTodos

query fetchAllTodos {
  todos {
    success
    errors
    todos {
      description
      completed
      id
    }
  }
}

• fetchTodo by Id

query fetchTodo {
  todo(todoId: "1") {
    success
    errors
    todo {
      id
      completed
      description
      dueDate
    }
  }
}

• Create new todo

mutation newTodo {
  createTodo(description: "Go to the dentist", dueDate: "24-08-2021") {
    success
    errors
    todo {
      id
      completed
      description
    }
  }
}

• mark todo completed

mutation markDone {
  markDone(todoId: "1") {
    success
    errors
    todo {
      id
      completed
      description
      dueDate
    }
  }
}

• Delete todo

mutation {
  deleteTodo(todoId: "1") {
    success
    errors
  }
}

• update due date

mutation updateDueDate {
  updateDueDate(todoId: "2", newDate: "25-08-2021") {
    success
    errors
  }
}

• Disable virtualenv

(todo_api_env)$ deactivate