How do I serve text/html #530

Jameswood-vega · 2024-07-31T23:56:49Z

Jameswood-vega
Jul 31, 2024

Hello Daniel,
we have recently adopted huma at my current employer, and have had great success with a data api we have built.
I am trying to expand my understanding of how to use this framework, but I can't figure out how to get it to serve good old html content.

for example I have modified the greetings example to return basic html.

I expected this to work.

package main

import (
	"context"
	"fmt"
	"net/http"

	"github.com/danielgtaylor/huma/v2"
	"github.com/danielgtaylor/huma/v2/adapters/humachi"
	"github.com/danielgtaylor/huma/v2/humacli"
	"github.com/go-chi/chi/v5"

	_ "github.com/danielgtaylor/huma/v2/formats/cbor"
)

// Options for the CLI. Pass `--port` or set the `SERVICE_PORT` env var.
type Options struct {
	Port int `help:"Port to listen on" short:"p" default:"8080"`
}

// GreetingOutput represents the greeting operation response.
type GreetingOutput struct {
	ContentType string `header:"Content-Type"`
	Body        struct {
		Message string `json:"message" example:"Hello, world!" doc:"Greeting message"`
	}
}

func main() {
	// Create a CLI app which takes a port option.
	cli := humacli.New(func(hooks humacli.Hooks, options *Options) {
		// Create a new router & API
		router := chi.NewMux()
		api := humachi.New(router, huma.DefaultConfig("My API", "1.0.0"))

		// Add the operation handler to the API.
		huma.Get(api, "/greeting/{name}", func(ctx context.Context, input *struct {
			Name string `path:"name" maxLength:"30" example:"world" doc:"Name to greet"`
		}) (*GreetingOutput, error) {
			resp := &GreetingOutput{}
			resp.Body.Message = fmt.Sprintf("<h1>Hello, %s!</h1>", input.Name)
			resp.ContentType = "text/html"
			return resp, nil
		})

		// Tell the CLI how to start your router.
		hooks.OnStart(func() {
			http.ListenAndServe(fmt.Sprintf(":%d", options.Port), router)
		})
	})

	// Run the CLI. When passed no commands, it starts the server.
	cli.Run()
}

But I get

2024/07/31 16:19:14 http: panic serving 127.0.0.1:44448: error marshaling response for GET /greeting/{name} 200: unknown content type: text/html

I have tried to figure it out on my own and I am stuck please help.

baderj · 2024-11-27T11:58:03Z

baderj
Nov 27, 2024

You probably shouldn't return plain HTML at all, but you can always set the Body to []byte to avoid serialization and just return raw bytes:

type GreetingOutput struct {
	ContentType string `header:"Content-Type"`
	Body        []byte `example:"<h1>Hello, world!</h1>" doc:"Greeting message"`
}

Then return the HTML as follows:

resp := &GreetingOutput{}
resp.Body = []byte(fmt.Sprintf("<h1>Hello, %s!</h1>", input.Name))
resp.ContentType = "text/html"
return resp, nil

1 reply

danielgtaylor Dec 5, 2024
Maintainer

Great answer, thanks! Also worth noting that if you do not need Huma's validation and input parsing then you can also just use the router in your example. Huma is happy to get out of the way when not needed!

router.Get("/", func(w http.ResponseWriter, r *http.Request) {
	w.Header().Set("Content-Type", "text/html")
	w.Write([]byte("<html><h1>Hello, world!</h1></html>"))
})

gwd · 2025-02-24T23:38:21Z

gwd
Feb 24, 2025

First off, thank you for the work you've done; I'm just playing around with it and seems quite useful.

FWIW I think there are legit reasons to return pre-rendered HTML content even through an API. My current website does HTMX-style server-side rendering of individual components of the page, which the front-end JS will request and then shove into page elements.

I managed to come up with the solution @baderj suggested, and came here to see if there was anything better.

It's OK, but it would be nicer if (e.g.) I could set contentType:"text/html" on the Body element of an output struct, and have Huma set the content type automatically.

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How do I serve text/html #530

Jameswood-vega Jul 31, 2024

Replies: 2 comments · 1 reply

baderj Nov 27, 2024

danielgtaylor Dec 5, 2024 Maintainer

gwd Feb 24, 2025

Jameswood-vega
Jul 31, 2024

Replies: 2 comments 1 reply

baderj
Nov 27, 2024

danielgtaylor Dec 5, 2024
Maintainer

gwd
Feb 24, 2025