rex

rex is a minimalistic but robust HTTP router built on Go 1.22’s enhanced http.ServeMux. It offers a range of features for rapid web application development, including:

• Middleware Support: Apply middleware globally or to specific routes and groups.
• Helper Methods: Simplify defining routes and working with request/response handlers.
• Template Rendering: Includes automatic template inheritance (e.g., using a base template), passing context data to templates, an error template that displays error messages, and more.
• Body Parsing: Supports decoding multiple content types:
  • JSON
  • XML
  • URL-encoded and multipart forms
    Works with standard Go types, pointers, slices, and custom types implementing the rex.FormScanner interface.
• Validation: Validate request data using the validator package.
• SPA Support:
  Use r.SPA to serve a single-page application.
• Route Grouping and Subgroups:
  Apply middleware to groups or individual routes for better organization.
• Built-in Middleware:
  • Logging: Uses Go’s slog package.
  • Panic Recovery: Gracefully handles panics.
  • ETag Support: For caching optimization.
  • CORS Handling: Cross-Origin Resource Sharing middleware.
  • Seesion based cookie auth, Basic Auth & JWT Middleware: Secure your routes with seesion, basic or token-based authentication.
  • CSRF Protection: Protect your routes from CSRF attacks with the CSRF middleware.
• Custom Middleware:
  Implement your own middleware by wrapping rex.Handler.
• Static File Serving:
  Use r.Static to serve static files from a directory or r.StaticFS to serve files from a http.FileSystem.

  Both of these method can serve the minified version of the files if present and rex.ServeMinifiedAssetsIfPresent is set to true. You can also easily convert standard HTTP handlers to rex handlers:

• Use rex.WrapHandler to wrap a http.Handler.
• Use rex.WrapFunc to wrap a http.HandlerFunc.
• Centralize error handling and logging by overriding the routers error handler. The default error handler handles rex.FormError from r.BodyParser and validator.ValidationErrors if there is a validation error.

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Installation

go get -u github.com/abiiranathan/rex

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Example: Custom Type Implementing FormScanner

This example shows how to implement a custom type that satisfies the FormScanner interface.

type Date time.Time // Date in format YYYY-MM-DD

// FormScan implements the FormScanner interface.
func (d *Date) FormScan(value interface{}) error {
	v, ok := value.(string)
	if !ok {
		return fmt.Errorf("date value is not a string")
	}

	t, err := time.Parse("2006-01-02", v)
	if err != nil {
		return fmt.Errorf("invalid date format")
	}
	*d = Date(t)
	return nil
}

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Rendering Templates

For a complete example of template rendering and router usage, see the example in cmd/server/main.go.

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Middleware

rex includes a few external libraries, used only in the middleware subpackage. Explore the middleware package for more details and usage examples.

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Tests

Run all tests with the following command:

go test -v ./...

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Benchmarks

Run benchmarks with memory profiling enabled:

go test -bench=. ./... -benchmem

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Contributing

Pull requests are welcome! For major changes, please open an issue to discuss your ideas first.
Don’t forget to update tests as needed.

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License

This project is licensed under the MIT License.