Unlocking the Power of Relay and Rust: A Game-Changing Combination

What is Relay?

Relay is a GraphQL client that allows you to think in terms of small scopes. By creating fragments, you can tell Relay to only source the specific data required inside a particular component. This approach, called colocation, prevents over-fetching and under-fetching data, resulting in better application performance.

The Power of Fragments

Fragments are reusable pieces of code that can be used in multiple components. They’re easy to refactor and make your application more efficient. With Relay, you can create fragments that stitch together at compile time, forming a query that fetches all the needed data.

fragment UserFragment on User {
  id
  name
  email
}

Data Masking: A Runtime Advantage

Relay’s data masking feature provides scope management at runtime. The compiler creates data files that serve each component its own required data, preventing components from accessing data they didn’t specify in their GraphQL fragments. This approach prevents data dependency bugs and provides stability to your application.

Why Relay Needs a Compiler

Relay uses a compiler to improve runtime performance and guarantee stability. By executing most of the components’ work and GraphQL communication at build time, Relay significantly improves application performance.

Refetching and Pagination Made Easy

Tasks like refetching data and pagination can be tricky to implement and error-prone. Relay’s APIs, such as useRefetchableFragment and usePaginationFragment, automate these tasks, making it easier to implement pagination in your app.

import { useRefetchableFragment } from 'elay';

const userFragment = useRefetchableFragment(
  graphql`
    fragment UserFragment on User {
      id
      name
      email
    }
  `,
  refetchVariables => ({ id: refetchVariables.userID }),
);

Automatic Type Generation

The Relay compiler enables automatic type generation, implementing type safety in your application and preventing bugs.

Optimizing Performance

The compiler optimizes performance by removing redundancies in queries, reducing the size of your query payload, and creating compact, optimized queries that run smoothly at runtime.

Using a Unique Query ID

Instead of sending a long query to your application’s server, the compiler generates a unique query ID, saving bandwidth and improving performance.

The Limitations of JavaScript

The previous compiler was written in JavaScript, which had performance limitations due to its single-threaded nature.

Why Rust?

Rust was chosen for its speed, memory safety, and concurrency features. With Rust, large data structures can be easily and safely shared across different threads.

Features of the New Rust Compiler

• TypeScript support
• Support for remote persisted queries
• The @no_inline directive
• The @required directive

Handling Null Values

The @required directive simplifies null checks, allowing you to specify what to do if a field is null.

fragment UserFragment on User {
  id
  name
  email @required
}

Why Many Use Rust to Rewrite JavaScript Tooling

Rust’s speed, performance, and memory efficiency make it an attractive choice for rewriting JavaScript tooling.