Lecture: Building a Backend Using Rust, Actix-Web, and SurrealDB

Introduction

• Objective: Learn how to build a backend using Rust, Actix-Web framework, and SurrealDB as the data layer.

Demo and Project Setup

• Tools: Postman for API demonstration
• Endpoints:
  • GET /pizzas: Get a list of pizzas
  • POST /buy_pizza: Buy a pizza
  • PATCH /update_pizza: Update a pizza
• Initial Rust Project Creation:
  • Create Rust project using cargo new r_backend
  • Navigate to project: cd r_backend
  • Default structure has Cargo.toml and src folder

Adding Dependencies

• Required Crates:
  • actix-web: Web framework
  • serde-json: JSON format handling
  • serde: Serialization/Deserialization
  • surrealdb: Database handling
  • uuid: Unique ID generation
  • validator: Data validation
  • async-std: Async functions
  • derive_more: Additional derive features
• Installation: Add these dependencies in Cargo.toml and build: cargo build

Writing Initial Code

• Endpoint handlers:
  • Define endpoint routes using Actix-Web macros
  • Implement basic GET, POST, PATCH handlers
  • Set up the main function with Actix-Web server
  • Use async functions for web handling
• Building and Running: Run using cargo run or cargo watch

Creating Models

• Define buy_pizza_request struct in models/pizza.rs
  • Use serde for serialization
  • Use validator for validation
• Configure models/mod.rs and main.rs to include new models

Handling Database (SurrealDB)

• Initialization: Set up and initialize SurrealDB
  • Install SurrealDB and check connection with Postman
  • Create db/database.rs for database interaction
• Database Struct: Define Database struct and implement init function for connection

Implementing CRUD Operations

• GET pizzas: Fetch data from SurrealDB
  • Implement get_all_pizzas function in database.rs
• POST buy_pizza: Add pizza data to SurrealDB
  • Implement data validation and pizza creation
• PATCH update_pizza: Update pizza data in SurrealDB
  • Fetch pizza by UUID and update it

Error Handling

• Custom Errors: Create pizza_error in errors.rs
  • Define error cases: NoPizzasFound, PizzaCreationFailure, NoSuchPizzaFound
  • Implement error responses using Actix-Web

Refactoring with Traits

• Creating Traits: Define pizza_data_trait.rs for pizza operations
  • Implement PizzaDataTrait for database interactions
• Code Refactoring: Move functions to trait implementation
  • Update endpoint handlers to use new trait functions

Conclusion

• Summary: Demonstrated how to build and update APIs in Rust using Actix-Web and SurrealDB
• Maintenance: Discussed the organization of code using traits for long-term maintainability
• Next Steps: Encourage adding more endpoints and exploring additional features

Final Thoughts

• Improvements: Emphasized code maintainability using traits
• Engagement: Suggested subscribing, liking, and sharing for more content

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