How do I make `http4k-template-thymeleaf` look for...

# http4k

[Mikael Ståldal]

How do I make http4k-template-thymeleaf look for templates with .html suffix? I am trying this:

data class Person(val name: String, val age: Int) : ViewModel

fun main() {
    val renderer = ThymeleafTemplates().CachingClasspath("templates")

    val app: HttpHandler = {
        val viewModel = Person("Bob", 45)
        Response(OK).body(renderer(viewModel))
    }

    app.asServer(SunHttp(8000)).start()
}

but it expects the template file to be Person (without suffix), I want it to be Person.html.

[dave]

Always check the tests first 🙃 . https://github.com/http4k/http4k/blob/8e32610524ed0294c53099f290cc4cd6c9669729/http4k-template/thymeleaf/src/test/kotlin/org/http4k/template/ThymeleafTemplatesTest.kt#L8

[Mikael Ståldal]

Ah, nice!

[Mikael Ståldal]

Seems like I cannot use Maven `exec:java` with http4k+Thymeleaf, since it uses `ClassLoader.getSystemClassLoader()`:
https://stackoverflow.com/questions/66375562/loading-resources-in-a-maven-project-with-exec-maven-plugin 😕

[s4nchez]

I'm aware of another example by @gypsydave5, but using handlebars: https://github.com/gypsydave5/todo-kotlin-htmx/tree/main

[gypsydave5]

ahahahah maybe I should tidy that up 😳

[s4nchez]

@gypsydave5 Why?! it's the greatest already 😛

[gypsydave5]

Needs the webdriver and maybe not using strikt...

[gypsydave5]

I'll make a todo list

[Mikael Ståldal]

Seems like the Thymeleaf integration does not really work as expected. According to the Thymeleaf documentation, you are supposed to be able to put fragments in footer.html, and refer to them with

th:insert="~{footer :: copy}"

but, I need to do

th:insert="~{footer.html :: copy}"

or rename the file to footer (without suffix).

So it seems like Thymeleaf expect the integrating framework to add a .html suffix automagically, which http4k does not.

[dave]

That seems like a failing of the actual lib because it should handle more than just HTML files (unless it magically takes the same suffix name as the current template).

Can you configure thymeleaf at all to do this for you? (When constructing the engine)

[Mikael Ståldal]

Not sure, I have not used Thymeleaf before.

[Mikael Ståldal]

But it seems like the Spring Boot integration does this.

[Mikael Ståldal]

And according to Thymeleaf docs, you are supposed to `setSuffix`:
https://www.thymeleaf.org/doc/tutorials/3.1/usingthymeleaf.html#the-template-resolver

[Mikael Ståldal]

Here I am specifying that the content type is HTML:

val renderer = ThymeleafTemplates().CachingClasspath("templates")
    val htmlLens = Body.viewModel(renderer, TEXT_HTML).toLens()

It would make sense if this also set .html suffix on the templates (which seems to be the convention for Thymeleaf), and maybe also templateResolver.setTemplateMode(TemplateMode.HTML).

[Mikael Ståldal]

If I also want to use templates for other formats than HTML which Thymeleaf supports, e.g. CSS, then I think it would make sense to have another lens with another renderer for that.

[Mikael Ståldal]

PR to use .html suffix by default for Thymeleaf templates: https://github.com/http4k/http4k/pull/942