graphql-mongodb-backend-example

This is a basic backend boilerplate for setting up a graphql server with mongodb and express.

installation

npm install

npm start

File structure

• config
  • index
• data
  • models
    • comment.js
    • index.js
    • post.js
    • user.js
  • services
    • commentService.js
    • index.js
    • postService.js -userService.js
  • types
    • customScalars
    • date.js
    • comment.js
    • post.js
    • query.js
    • user.js
  • index.js
  • node.js
  • schema.graphql
  • schema.js
  • schema.json
• node_modules
• scripts
  • schema
    • updateSchema.js
  • seed
    • seedDatabase.js
• .babelrc
• gitignore
• package.json
• server.js
• webpack.config.js

GraphQL

go to http://localhost:8080/graphql to work with the graphqil to make queries from schema.js root query is:

export var Schema = new GraphQLSchema({
  query: QueryType,
});

QueryType has these fields that can be queried on: in types/query.js

• node
• users : retrieves all users
• user(id) : retrieves user by id
• posts : retrieves all posts
• post(id) : retrieves post by id
• comments : retrieves all comments
• comment(id) : retrieves all comments by id

graphiql queries look like this:

Database

Models

• user
• post
• comment

Example schema in [model].js

import mongoose from 'mongoose';

let newModelSchema = new mongoose.Schema({
  _id: {
    type: String,
    required: true,
    default: mongoose.Types.ObjectId,
  content: {
    type: String,
  },
  createdAt: {
    type: Date,
    default: Date.now,
  },
  //add in field for graphql type 
  type: { 
    type: String,
  }
})

export default mongoose.model('User', UserSchema);

Schema

Node interface and Node field

Node Interface used for re-fetching of objects

let nodeInterface = new GraphQLInterfaceType({
  name: 'Node',
  description: 'An object with an ID',
  fields: () => ({
    id: {
      type: new GraphQLNonNull(GraphQLID),
      description: 'The global unique ID of an object'
    },
    type: {
      type: new GraphQLNonNull(GraphQLString),
      description: "The type of the object"
    }
  }),
  resolveType: (obj) => {
    if (obj.type === 'user') {
      return UserType;
    } else if (obj.type === 'post') {
      return PostType;
    } else if (obj.type === 'comment') {
      return CommentType;
    }
  }
});

module.exports = {
  nodeInterface: () => [ nodeInterface ], //wrap nodeInterface in function to avoid circular dependency issues 
  nodeField: nodeField,
}