Using templ for Go code codegen

[danicc097]

I've been experimenting a bit to replace stdlib go templates with templ for go codegen (not html). The potential is huge but there are some drawbacks I quickly found:

• Escaping is enabled by default, so the output will not be valid go code unless templ.Raw is used, and if I make a custom component implementing templ.Component I will lose LSP help. templ.Raw won't work in expressions like:

  for _, lang := range data.Langs {
       { @templ.Raw(fmt.Sprintf(`Lang%s Lang = "%s"`, lang.CamelLang, lang.Lang)) }
  }

• Code is harder to read with templ.Raw( ... ) everywhere and no syntax highlighting like with html.

So in short:

1. Is there a workaround for the escaping issue above?
2. Is it feasible to have an alternate syntax where templ expressions are the ones escaped, in a similar vein to stdlib templates? E.g. the code below (if set to templ language mode in vscode) already has syntax highlighting, and its a matter of finding some expression syntax. A marker comment on top of the .templ files could be used for both the extension and the templ generate to handle go codegen properly (no escaping for templ generate, syntax change in IDE...). This would also open the door to having explicit support to generate other types of files, not just go|html (none come to mind now though)

package templates

import "fmt"

templ TranslationCode2(data TemplateData) {
	{{ // templ comments }}
	// Code generated by i18ngo. DO NOT EDIT.
	package translation

	import (
		"bytes"
		"html/template"
	)

	// Translator is implemented by all language translators.
	type Translator interface {
	  {{ // templ comments }}
            {{ for _, msg := range data.Messages }}
              {{ fmt.Sprintf("%s (%s) (string, error)", msg.MethodName, msg.Args) }}
            {{ end }}
	}

	// Lang represents available translated languages.
	type Lang string

	const (
	    {{ // templ comments }}
	  {{ for _, lang := range data.Langs }}
		  {{ fmt.Sprintf(`Lang%s Lang = "%s"`, lang.CamelLang, lang.Lang) }}
	  {{ end }}
	)

	// NewTranslators initializes all translators.
	func NewTranslators() map[Lang]Translator {
		return map[Lang]Translator{
              {{ for _, lang := range data.Langs }}
                {{ fmt.Sprintf(`// writing var %q to comment`, lang.Lang) }}
              {{ end }}
                }
          }
}

[joerdav]

Hey @danicc097

We've gone back and forth a few times on this and landed on a focus of HTML at the moment. See #385 (comment)

I think there is demand and a gap in the Go ecosystem for a non-HTML templ, because we have had a few requests and questions around it.

I agree that it would be a great way to do go codegen, but as of now it's not a goal of templ, we want to get HTML right for now :)