Trivia API is a backend web development project created for the Full Stack Developer Nanodegree at Udacity. The goal of the project was to:

• Create all necessary endpoints on the backend to serve the frontend, enabling the visitor of the website to:
  • View all trivia questions stored in a database
  • View trivia questions based on their category
  • Add and delete questions to the database
  • Play trivia in a chosen category, getting random questions from the database
• Apply test-driven development, writing unit tests for each endpoint
• Make modifications to the frontend and database if necessary

The site runs on localhost and was created only for educational purposes.

• SQLAlchemy ORM as the ORM library
• PostgreSQL for the database
• Python3 and Flask as the server language and server framework
• HTML, CSS, and Javascript with Node.js and React for the frontend

All endpoints accept JSON encoded requests and return JSON encoded bodies. The following endpoints were implemented to serve requests from the frontend, interacting with the database:

/questions

• GET request:

  • returns:
  • a paginated list of questions according to the provided page parameter
  • the total number of questions as ```total_questions,
  • the categories as categories,
  • and the boolean success parameter in the body
  • example response:

    {
      "questions": [
          {
             "Question": "Who invented Peanut Butter?",
             "Answer": "George Washington Carver",
             "Category": 2,
             "Difficulty": 2
          },
          etc...
          ],
      "categories":
          {
             "1": "Science",
             "2": History",
             etc...
          },
      "success": true, 
      "totalQuestions": 13
    }
    

• POST request:

  • has 2 different functionalities: searching for questions and posting new questions
  • if searchTerm is found in the body, a list of case-insensitive search results is returned as well as the total number of results as totalQuestions
  • otherwise, a new question is inserted using the provided questions, answer, difficulty, category parameters provided and the boolean success parameter is returned in the response body
  • example response in case of searching for the term "peanut":

  {
    "questions": [
     {
       "answer": "George Washington Carver", 
       "category": 4, 
       "difficulty": 2, 
       "id": 12, 
       "question": "Who invented Peanut Butter?"
     }
   ], 
    "success": true, 
    "totalQuestions": 1
  }
  

/questions/[int:question_id]

• DELETE request:
  • deletes the question with ID == question_id from the database
  • returns the boolean success parameter in the body

/categories

• GET request:
  • returns a list of categories with IDs and category strings in a categories parameter, such as:

  {
    "success": "True"
    "categories":
    {
       "1": "Science",
       "2": History",
       etc...
    }
  }
  

/categories/[int:category_id]/questions

• GET request:
  • returns:
  • a list of questions with category == category_id,
  • the total number of questions as totalQuestions
  • the current category as currentCategory,
  • and the boolean success parameter
  • example response:

  {
    "success": True
    "questions": [
    {
       "Question": "Who invented Peanut Butter?",
       "Answer": "George Washington Carver",
       "Category": 2,
       "Difficulty": 2
    },
    etc...
    ],
    "totalQuestions": 5,
    "currentCategory": 2
  }
  

/add

• GET request:
  • assists in loading the 'Add' page
  • returns the boolean success parameter in the body

/quizzes

• POST request:
  • returns a non-recurring random question from a category based on quiz_category.id provided in the request body
  • returns the boolean success parameter in the body
  • example:

  {
    "success": True
    "question":
    {
       "Question": "Who invented Peanut Butter?",
       "Answer": "George Washington Carver",
       "Category": 2,
       "Difficulty": 2
    }
  }
  

Virtual environment

To start and run the local development server, initialize and activate a virtual environment:

$ cd YOUR_PROJECT_DIRECTORY_PATH/
$ virtualenv --no-site-packages env
$ source env/bin/activate

Install dependencies:

$ pip install -r requirements.txt

Key Dependencies:

• Flask is a lightweight backend microservices framework. Flask is required to handle requests and responses.
• SQLAlchemy is the Python SQL toolkit and ORM that handles the lightweight sqlite database.
• Flask-CORS is the extension used to handle cross origin requests from the frontend server.

Database Setup

With Postgres running, restore a database using the trivia.psql file provided. After creating a database called trivia, from the backend folder in terminal run:

psql trivia < trivia.psql

Running the server

To run the server, execute:

export FLASK_APP=flaskr
export FLASK_ENV=development
flask run

Running the frontend

First, install Node.js and npm.

Then, to run the frontend, execute:

npm start