Relay specification compliance in GraphQL - Mini Project: Build & Apply

Relay Specification Compliance with GraphQL

📖 Scenario: You are building a simple GraphQL API for a blog. The API must follow the Relay specification to support pagination and global object identification.

🎯 Goal: Create a GraphQL schema that implements Relay-compliant connections for a list of blog posts, including nodes, edges, and pageInfo fields.

📋 What You'll Learn

Create a Post type with id and title fields

Implement a PostConnection type with edges and pageInfo

Use cursor and node in edges

Add a posts query that returns a PostConnection

Include first and after arguments for pagination

💡 Why This Matters

🌍 Real World

Relay-compliant GraphQL APIs are used in modern web apps to efficiently fetch and paginate data.

💼 Career

Understanding Relay specification is important for frontend and backend developers working with GraphQL in production.

1

Define the Post type with id and title

Create a GraphQL type called Post with two fields: id of type ID! and title of type String!.

GraphQL

# Define the Post type with id and title fields
# Your code here

Need a hint?

Use type Post { id: ID! title: String! } to define the Post type.

2

Create the PostEdge and PostConnection types

Add a PostEdge type with cursor of type String! and node of type Post. Then create a PostConnection type with edges as a list of PostEdge and pageInfo of type PageInfo!.

GraphQL

type Post {
  id: ID!
  title: String!
}

# Define PostEdge and PostConnection types
# Your code here

Need a hint?

Define PostEdge with cursor and node, then PostConnection with edges and pageInfo.

3

Add the PageInfo type for pagination info

Create a PageInfo type with four fields: hasNextPage and hasPreviousPage of type Boolean!, and startCursor and endCursor of type String.

GraphQL

type Post {
  id: ID!
  title: String!
}

type PostEdge {
  cursor: String!
  node: Post
}

type PostConnection {
  edges: [PostEdge]
  pageInfo: PageInfo!
}

# Define PageInfo type
# Your code here

Need a hint?

PageInfo holds pagination booleans and cursors.

4

Add the posts query with first and after arguments

Add a Query type with a posts field that returns a PostConnection. The posts field should accept two arguments: first of type Int and after of type String.

GraphQL

type Post {
  id: ID!
  title: String!
}

type PostEdge {
  cursor: String!
  node: Post
}

type PostConnection {
  edges: [PostEdge]
  pageInfo: PageInfo!
}

type PageInfo {
  hasNextPage: Boolean!
  hasPreviousPage: Boolean!
  startCursor: String
  endCursor: String
}

# Add Query type with posts field accepting first and after arguments
# Your code here

Need a hint?

The Query type defines the entry point for fetching posts with pagination arguments.