API Development and Documentation

Trivia App

This Trivia app allows users to play a trivia game where they test their knowledge by answering trivia questions The web application offers the following functionalities

1. Display questions - both all questions and by category. Questions should show the question, category and difficulty rating by default and can show/hide the answer.
2. Delete questions
3. Add questions and require that they include question and answer text.
4. Search for questions based on a text query string.
5. Play the quiz game, randomizing either all questions or within a specific category.

About the Stack

The backend direcory contains files to setup the backend to enable communication with the front end and viewing of data from the database

View the Backend README for more details.

Frontend

The frontend directory contains a complete React frontend to consume the data from the Flask server. If you have prior experience building a frontend application, you should feel free to edit the endpoints as you see fit for the backend you design. If you do not have prior experience building a frontend application, you should read through the frontend code before starting and make notes regarding:

1. What are the end points and HTTP methods the frontend is expecting to consume?
2. How are the requests from the frontend formatted? Are they expecting certain parameters or payloads?

Pay special attention to what data the frontend is expecting from each API response to help guide how you format your API.

View the Frontend README for more details.

Getting Started

Developers should have Python3,node, npm installed

Install Dependencies

1. Python 3.7 - Follow instructions to install the latest version of python for your platform in the python docs

2. Virtual Environment - We recommend working within a virtual environment whenever using Python for projects. This keeps your dependencies for each project separate and organized. Instructions for setting up a virual environment for your platform can be found in the python docs

3. PIP Dependencies - Once your virtual environment is setup and running, install the required dependencies by navigating to the /backend directory and running:

pip install -r requirements.txt

Key Pip Dependencies

• Flask is a lightweight backend microservices framework. Flask is required to handle requests and responses.

• SQLAlchemy is the Python SQL toolkit and ORM we'll use to handle the lightweight SQL database. You'll primarily work in app.pyand can reference models.py.

• Flask-CORS is the extension we'll use to handle cross-origin requests from our frontend server.

Set up the Database

With Postgres running, create a trivia database:

createbd trivia

Populate the database using the trivia.psql file provided. From the backend folder in terminal run:

psql trivia < trivia.psql

Run the Server

From within the ./src directory first ensure you are working using your created virtual environment.

To run the server, execute:

export FLASK_APP=flaskr
export FLASK_ENV=development
python -m flask run

setting the FLASK_APP=flaskr will allow the detection of flask app __init__py in the flaskr diretory

setting FLASK_ENV=development enables auto detect on the changes made during development process

API Reference

Getting started

• Backend base URL : http://127.0.0.1:5000/
• Front end base URL: http://127.0.0.1:3000/
• Authentication : Authentication and API keys have not been used in this application

Testing

To deploy the tests, run

dropdb trivia_test
createdb trivia_test
psql trivia_test < trivia.psql
python test_flaskr.py

Error Handling

Errors are returned as json object in the following format

{
    "success": False, 
    "error": 400,
    "message": "bad request"
}

The API returns three types of errors

• 404 :Not Found
• 400 :Bad Request
• 422 :Not processable

End points

GET '/categories'

• Returns an object of categories ordered by id,that contains an object of id:category_string key:value pairs, success value and total number of categories
• Sample : curl http://127.0.0.1:5000/categories

{
  "1": "Science",
  "2": "Art",
  "3": "Geography",
  "4": "History",
  "5": "Entertainment",
  "6": "Sports"
}

GET '/questions'

• Returns a paginated set of questions ,total number of questions
• Sample curl http://127.0.0.1:5000/questions

{
  "categories": {
    "1": "Science",
    "2": "Art",
    "3": "Geography",
    "4": "History",
    "5": "Entertainment",
    "6": "Sports"
  },
  "questions": [
    {
      "answer": "Tom Cruise",
      "category": 5,
      "difficulty": 4,
      "id": 4,
      "question": "What actor did author Anne Rice first denounce, then praise in the role of her beloved Lestat?"
    },
    {
      "answer": "Muhammad Ali",
      "category": 4,
      "difficulty": 1,
      "id": 9,
      "question": "What boxer's original name is Cassius Clay?"
    },
    {
      "answer": "Brazil",
      "category": 6,
      "difficulty": 3,
      "id": 10,
      "question": "Which is the only team to play in every soccer World Cup tournament?"
    },
    {
      "answer": "Uruguay",
      "category": 6,
      "difficulty": 4,
      "id": 11,
      "question": "Which country won the first ever soccer World Cup in 1930?"
    },
    {
      "answer": "George Washington Carver",
      "category": 4,
      "difficulty": 2,
      "id": 12,
      "question": "Who invented Peanut Butter?"
    },
    {
      "answer": "Lake Victoria",
      "category": 3,
      "difficulty": 2,
      "id": 13,
      "question": "What is the largest lake in Africa?"
    },
    {
      "answer": "The Palace of Versailles",
      "category": 3,
      "difficulty": 3,
      "id": 14,
      "question": "In which royal palace would you find the Hall of Mirrors?"
    },
    {
      "answer": "Agra",
      "category": 3,
      "difficulty": 2,
      "id": 15,
      "question": "The Taj Mahal is located in which Indian city?"
    },
    {
      "answer": "Escher",
      "category": 2,
      "difficulty": 1,
      "id": 16,
      "question": "Which Dutch graphic artist\u2013initials M C was a creator of optical illusions?"
    },
    {
      "answer": "Mona Lisa",
      "category": 2,
      "difficulty": 3,
      "id": 17,
      "question": "La Giaconda is better known as what?"
    }
  ],
  "success": true,
  "total_questions": 27
}

DELETE '/questions/{question_id}

• Deletes the question of the given id if it exists
• Returns a success value, id of the deleted question and total number of questions
• sample curl -X DELETE http://127.0.0.1:5000/14

{
  "delete_id": 14,
  "success": true,
  "total_questions": 24
}

POST '/questions'

• Creates a new question using the submitted question,answer,category and difficulty
• Returns success value,id of created question and total number of questions
• sample curl http://127.0.0.1:5000/questions -X POST -H "Content-Type: application/json" --data "{\"question\": \"Frankie Fredericks represented which African country in athletics?\", \"answer\": \"Cleo\", \"difficulty\": \"3\", \"category\": \"6\" }"

{
  "created": 36,
  "success": true,
  "total_questions": 25
}

POST '/questions'

• Returns questions that match the searchTerm,success,total search query
• sample curl http://127.0.0.1:5000/questions -X POST -H "Content-Type: application/json" -d "{\"searchTerm\": \"what\"}"

{
  "questions": [
    {
      "answer": "Muhammad Ali",
      "category": 4,
      "difficulty": 1,
      "id": 9,
      "question": "What boxer's original name is Cassius Clay?"
    },
    {
      "answer": "Lake Victoria",
      "category": 3,
      "difficulty": 2,
      "id": 13,
      "question": "What is the largest lake in Africa?"
    },
    {
      "answer": "Mona Lisa",
      "category": 2,
      "difficulty": 3,
      "id": 17,
      "question": "La Giaconda is better known as what?"
    },
    {
      "answer": "The Liver",
      "category": 1,
      "difficulty": 4,
      "id": 20,
      "question": "What is the heaviest organ in the human body?"
    },
    {
      "answer": "Blood",
      "category": 1,
      "difficulty": 4,
      "id": 22,
      "question": "Hematology is a branch of medicine involving the study of what?"
    },
    {
      "answer": "bop",
      "category": 3,
      "difficulty": 5,
      "id": 28,
      "question": "whats my name"
    }
  ],
  "success": true,
  "total_results": 6
}

GET '/categories/{category_id}/questions

• Retrives questions with a given category id
• Returns success value, paginated questions with the given category id,total questions
• sample curl http://127.0.0.1:5000/categories/1/questions

{
  "questions": [
    {
      "answer": "Muhammad Ali",
      "category": 4,
      "difficulty": 1,
      "id": 9,
      "question": "What boxer's original name is Cassius Clay?"
    },
    {
      "answer": "Lake Victoria",
      "category": 3,
      "difficulty": 2,
      "id": 13,
      "question": "What is the largest lake in Africa?"
    },
    {
      "answer": "Mona Lisa",
      "category": 2,
      "difficulty": 3,
      "id": 17,
      "question": "La Giaconda is better known as what?"
    },
    {
      "answer": "The Liver",
      "category": 1,
      "difficulty": 4,
      "id": 20,
      "question": "What is the heaviest organ in the human body?"
    },
    {
      "answer": "Blood",
      "category": 1,
      "difficulty": 4,
      "id": 22,
      "question": "Hematology is a branch of medicine involving the study of what?"
    },
    {
      "answer": "bop",
      "category": 3,
      "difficulty": 5,
      "id": 28,
      "question": "whats my name"
    }
  ],
  "success": true,
  "total_results": 6
}

POST '/quizzes'

• Takes two parameters, category and previous questions
• Returns a success value, random questions not in the previous question

{
  "question": {
    "answer": "The Liver", 
    "category": 1, 
    "difficulty": 4, 
    "id": 20, 
    "question": "What is the heaviest organ in the human body?"
  }, 
  "success": true
}

Authors

• Cleophas Kadima

Acknowledgements

• Udacity