Introduction

This is the source code for the article "How to Build Systems Using GraphQL HotChocolate: A Step-by-Step Guide" at https://blog.tranchy.tech/how-to-build-systems-using-graphql-hotchocolate-a-step-by-step-guide.

The source code and configuration related to the backend are located in the Backend folder.

Setup

Here are the instructions to help run the backend system successfully.

Install dotnet tools

In the Backend folder, run the command dotnet tool restore to install the tools to support HotChocolate's schema compilation.

Run databases

In the Backend folder, run the command docker compose up mongo sql redis -d

Authorization

We use the user-jwts feature of the dotnet tool to simplify the authentication process because it is not in the scope of the article.

One thing to note is that by default this feature only applies to the scope of each project, so each project will have a different signing key.

Therefore, to ensure that the access token is accepted at the solution level, that is, all projects, we must ensure that all signing keys are the same.

We can do this by selecting a project to generate access tokens for. Then copy the signing key from that project's user secret to the other projects. See the appsettings.development.json file of each project for more information.

Here is a sample command to generate access tokens corresponding to the parameters configured in the projects:

dotnet user-jwts create --name AdminUser --role admin --role customer --issuer tranchy.tech --expires-on 2029-12-12 --audience https://ask.api --audience https://payment.api --audience https://webff --audience https://mobilebff --claim http://schemas.xmlsoap.org/ws/2005/05/identity/claims/emailaddress=customer1@example.com

Predefined access token with same signing key for all projects

Name: AdminUser

Roles: [admin, customer]

Token:

eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJ1bmlxdWVfbmFtZSI6IkFkbWluVXNlciIsInN1YiI6IkFkbWluVXNlciIsImp0aSI6IjQwYWYwOTk1Iiwicm9sZSI6WyJhZG1pbiIsImN1c3RvbWVyIl0sImVtYWlsIjoiY3VzdG9tZXIxQGV4YW1wbGUuY29tIiwiYXVkIjpbImh0dHBzOi8vYXNrLmFwaSIsImh0dHBzOi8vcGF5bWVudC5hcGkiLCJodHRwczovL3dlYmZmIiwiaHR0cHM6Ly9tb2JpbGViZmYiXSwibmJmIjoxNzIxNjM5MTY5LCJleHAiOjE4OTE3MjgwMDAsImlhdCI6MTcyMTYzOTE2OSwiaXNzIjoidHJhbmNoeS50ZWNoIn0.ZWQQx7mYJSzDF894XrUCZXIHCZkhAWJAQx6t91D2YqE

Sample operations

Queries

query {
  deposits(where: { status: { eq: "Init" } }) {
    nodes {
      id
      questionId
      status
      amount
    }
  }
}

query getQuestions {
  questions {
    communityShareAgreement
    createdBy
    createdOn
    id
    priorityKey
    status
    supportLevel
    title
    categoryKeys
    questionCategories {
      key
      description {
        value
        key
      }
    }
  }
}

query getQuestions {
  questions {
    communityShareAgreement
    createdBy
    createdOn
    id
    priorityKey
    status
    supportLevel
    title
    categoryKeys
    questionCategories {
      key
      description {
        value
        key
      }
    }
  }
}

Mutations

mutation createQuestion($input: CreateQuestionInput!) {
  createQuestion(input: $input) {
    question {
      categoryKeys
      comment
      communityShareAgreement
      createdBy
      createdOn
      id
      modifiedOn
      priorityKey
      status
      supportLevel
      title
    }
    errors {
      ... on NotFoundCategoryError {
        __typename
        categoryKeys
        message
      }
    }
  }
}

{
  "input": {
    "title": "",
    "categoryKeys": [],
    "communityShareAgreement": true,
    "priorityKey": "TODAY",
    "supportLevel": "AGENCY"
  }
}

Subscriptions

subscription {
  questionCreated {
    categoryKeys
    communityShareAgreement
    createdBy
    createdOn
    id
    priorityKey
    status
    supportLevel
    title
    questionCategories {
      createdOn
      id
      key
      modifiedOn
    }
  }
}