GraphQL example

Backend

The backend is developed using Spring boot 2, the GraphQL Java implementation and the Spring boot starter.

Installation

No additional installation is necessary before being able to run the application. However, you can always load the dependencies and generate the JAR file using the following command:

./mvnw clean package

Configuration

The backend can be ran properly without any additional configuration. However, the demo code used a hardcoded profile ID to store new questions and answers. So to make this example work, it's recommended to create a file called tech-talk-api/src/main/resources/data.sql and to include the following content:

INSERT INTO profile (id, username, title, email, bio) VALUES
  (1, 'g00glen00b', 'Software engineer', '[email protected]', 'Consultant at Cronos and Tech lead at Aquafin. Usually you can find me trying out new libraries and technologies. Loves both Java and JavaScript.');

Obviously, you're free to change the data to whatever you'd like.

Running

To run the application, you can use the following Maven command:

./mvnw spring-boot:run

This will compile the application and run it at port 8080.

Frontend

The frontend is developed using Angular 7 and Apollo GraphQL.

Installation

To install the required dependencies, you can use the following command:

npm install

Configuration

No additional configuration is required.

Running

To run the application, you can use the following npm script:

npm start

Snippets

The following snippets have been used during the presentation:

Type definition

type Organization {
    id: ID!
    name: String
    employees: [Employee]
    employeeCount: Int
}

Query type definition

type Query {
    organizations(offset: Int, limit: Int): [Organization]
    organization(id: ID!): Organization
    organizationCount: Int
    employees(offset: Int, limit: Int): [Employee]
    employee(id: ID): Employee
    employeeCount: Int
}

Mutation type definition

type Mutation {
    createOrganization(input: OrganizationInput!): Organization
    deleteOrganization(id: ID!): Boolean
}

Input type definition

input OrganizationInput {
    name: String
}

Java resolver

public int getEmployeeCount(Organization organization) {
    return employeeRepo.countByOrganization(organization);
}

JavaScript resolver

return {
  employeeCount: ({id}) => Employee.count({organization: id})
};

Querying

query AllOrganizations($offset: Int, $limit: Int) {
    organizations(offset: $offset, limit: $limit) {
        id
        name
        employeeCount
    }
}

{"offset": 0, "limit": 10}