GraphQL 

Benefits of GraphQL

• Less code
• More declarative / elegant data retrieval
• Avoids multiple REST calls
• Backward compatible and version-free
• Flexible
• Performance is better
• Powerful development tools
• Can evolve without versions

What GraphQL offers?

This is a simple query

This is a simple mutation

Calling Mutations with Variables​

...and this is a subscription

Setting up Apollo Client in your React or React Native Project

All queried data is available in the props of the same component !!

GraphQL Clients

• Relay: powerful GraphQL client developed by Facebook, heavily optimized for performance. It is only available on the web.

• Apollo Client: community-driven effort to build a powerful, flexible and production ready GraphQL client for all major development platforms. It supports various frontend frameworks (React, Angular and Vue) and platforms (iOS, Android).

GraphQL Servers

• Graphql-tools: 

A package that enables you to build a production-ready GraphQL.js schema using the GraphQL schema language

• Apollo-server: 

A production-ready Node.js GraphQL server library that supports Express, Connect, Hapi, Koa, and other popular Node HTTP servers, with built-in features like persisted queries, batching, and more. Apollo Server works with any GraphQL client, like Apollo, Relay, and more.

Limitations

• GraphQL Subscriptions lag sometimes.

• Passing variables to a query is tricky and require props to be passed from a wrapper component.

• The official docs of Apollo Client provide simple and generic examples that ​are difficult to apply to large-scale apps.

What we used

For the Chat App...

QUERIES

• Fetching all Users registered on the app

• Fetching all Messages and filtering based on sender and receiver id's

MUTATIONS

• Creating a new user (Sign Up)

• User Login (Returns a token)

SUBSCRIPTIONS

• Creating a new message

• Listening to the websocket whenever a new user is created or whenever a new message is sent for real-time applications

• Creating a new message

git commit -am "I am done with my tech talk"

Questions?