huma/examples/echo/echo.go

package main

import (
	"net/http"
	"strings"

	"github.com/danielgtaylor/huma"
	"github.com/danielgtaylor/huma/cli"
	"github.com/danielgtaylor/huma/responses"
)

// Standard middleware is supported, works with streaming. Useful for stuff
// like compression, request IDs, panic recovery/logging, etc.
func requestIDMiddleware(next http.Handler) http.Handler {
	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
		w.Header().Set("Request-ID", "abc123")
		next.ServeHTTP(w, r)
	})
}

// EchoRequest is the request input
type EchoRequest struct {
	Word  string `path:"word" doc:"The word to echo back. Cannot be 'test'."`
	Greet bool   `query:"greet" doc:"Return a greeting" default:"false"`
	Foo   int    `query:"foo" enum:"1,3,5,7" doc:"..."`
}

// Resolve does additional validation / transformation
func (e *EchoRequest) Resolve(ctx huma.Context, r *http.Request) {
	// Extra validation for returning exhaustive errors. Huma handles returning
	// the actual errors after resolving all request dependencies.
	if e.Word == "test" {
		ctx.AddError(&huma.ErrorDetail{
			Message:  "disallowed word value",
			Location: "path.word",
			Value:    e.Word,
		})
	}

	// Post-processing of fields. You can also access the raw request for
	// anything you can't model via tags.
	e.Word = strings.ToLower(e.Word)
}

// EchoResponse message which echoes a value.
type EchoResponse struct {
	Value string `json:"value"`
	Foo   int    `json:"foo,omitempty"`
}

func main() {
	app := cli.NewRouter("My API", "1.0.0")

	app.Middleware(requestIDMiddleware)

	app.Resource("/echo/{word}").
		//WithTags("echo-tag").
		Get("echo", "Echo back an input word",
			responses.OK().Headers("Etag").Model(EchoResponse{}),
			responses.BadRequest(),
		).
		//WithDeadline(30 * time.Second).
		Run(func(ctx huma.Context, input EchoRequest) {
			v := input.Word
			if input.Greet {
				v = "Hello, " + v
			}

			ctx.Header().Set("ETag", `W/"foo"`)
			ctx.WriteModel(http.StatusOK, EchoResponse{
				Value: v,
				Foo:   input.Foo,
			})
		})

	app.Run()
}