reimagined-broccoli

Product Features

• Listing of all the links (no login required)
• Link Creation
• User Creation
• JWT Based authentication
• Vote registration and unregistration by logged in Users

Python env

• The project uses Python 3.7. Use PyEnv to install the required version
• Python environment in managed through Poetry
• Install Poetry using instructions present here
• Install the project virtual env and packages using the command. Make sure you have set the local Python version to 3.7

poetry install

• Start the project virtual env using the command

poetry shell

• To check out more details about your virtualenv please run the command

poetry env info

• In case of questions, please checkout the guide to maintaining virtual envs and python versions with over here

Application Details

• Python 3.7
• Django 2.2
• Django Filters
• Graphene Django
• Django GraphQL JWT
• The Insomnia API collection can be used to interact with the application locally is present over here

API interaction

• The GraphQL interface can be accessed using the inbuilt Graphene UI present at localhost:8000/grapqhl but it does not support JWT Auth
• To use GraphQL with JWT Auth checkout Insomnia or Postman

Precommit hooks

• isort
• flake8
• black
• in built precommit checks

Seed data

• From the root of the repo, run the following management command to generate the seed data

python manage.py seed_data

GraphQL

• The GraphQL interface can be accessed at localhost:8000/graphql
• GraphQL interfaces are of the following types:
  • Query - analogous to DQL statemets
  • Mutations - analogous to DML and DDL statements

---

Query

• Fetch Links data

query {
  links{
    id
    url
    linkVotes{
      created
      user{
        username
      }
    }
    postedBy{
      username
    }
  }
}

• Fetch HNUsers data

query{
  hnUsers{
    bio
    username
    email
    superuserAccess
  }
}

• Fetch JWT token user Details

# provide the JWT in Auth headers

query{
  me {
    username
    email
  }
}

• Fetch List of Links with the HN User Information

query {
  links{
    id
    url
    postedBy{
      username
    }
  }
}

• Fetch List of Votes

query {
  votes{
    created
    link{
      url
    }
    user{
      username
    }
  }
}

• List of Votes filtered by Vanilla Search using Q operator

query {
  vanillaFilteredLinks(search: "gringotts"){
    url
  }
}

• Paginate the List of links data by using skip and page size (first):

query {
  paginatedLinks(search: ".com", skip:10, first: 20){
    url
    description
  }
}

query {
  paginatedLinks(search: ".biz", first: 3){
    url
    description
  }
}

• Using Relay and Graphene to generate Edges and Nodes. Edges are a collection of nodes and Relay allows for pagination functionality out of the box

query {
  relayLinks(first: 3) {
    edges {
      node {
        id
        url
        description
        linkVotes {
          edges {
            node {
              id
              created
              user {
                username
              }
            }
          }
        }
      }
    }
    pageInfo {
      startCursor
      endCursor
    }
  }
}

---

Mutations

• Create Link

mutation {
  createLink(
  description: "Hustlers Den",
  url: "https://github.com/darth-dodo/hustlers-den"
  ){
    url
    description
    id
  }
}

mutation {
  createLink(url: "https://github.com/darth-dodo/discuss-it", description: "Phoenix and Elixir clone") {
    id
    url
    description
    postedBy {
      username
      email
    }
  }
}

• Create HN User

mutation {
  createHnUser(
    bio: "dummy bio"
    email: "dummy-user@email.com"
    password: "dummypassword"
    username: "dummy-1"
  ){
    hnUser {
      bio
    }
  }
}

# generate the JWT payload

mutation {
  tokenAuth(username: "dummy-1", password: "dummypassword"){
    payload
  }
}

# generate the JWT token

mutation {
  tokenAuth(username: "dummy-1", password: "dummypassword"){
    token
  }
}

# verify the JWT token

mutation {
  verifyToken(token: "eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJ1c2VybmFtZSI6ImR1bW15LTEiLCJleHAiOjE1ODczMDg5NjksIm9yaWdJYXQiOjE1ODczMDg2Njl9.sBVGWqOnHxWv7f1zeJqb6V-CUZGZ4rxKDEIbqLtsZQY"){
    payload
  }
}

• Create Vote

mutation {
  createVote(linkId: 4){
    vote {
      created
      user {
        username
      }
      link {
        url
      }
    }
  }
}

• Register Unvote

mutation {
  registerUnvote(linkId: 4){
    success
  }
}

• Create a Link using the Relay functionality

mutation {
  relayCreateLink(input: {
    url: "https://github.com/darth-dodo/meal-helper",
    description:  "Meal Plan Management tool"
  }) {
    link {
      id
      created
      url
      description
    }
  }
}

Error Handling

• GraphQL servers don't return anything but 200 and 500
• Custom middleware can handle errors of the instance GraphQLError if specific responses are desired

Further Reading

• Four years of GraphQL
• Graphene in Detail
• GraphQL official learning guide