I'm writing a functionality that isn't a plugin but simply an extension function (I see no need for a full-flegded plugin for this) where the functionality exposes path with

get

and

post

routes. The

post

would handle, preprocess, and then delegate to call scoped callback, the form contents that the

get

route builds and sends (normal HTML form). I'd like to make it possible for the user to use what ever templating they choose to create the HTML page and the form, but I'd also need them to have some predefined fields in the form. Would there be any universal way to inject the needed raw HTML into the page, or would I need to offer some form of interface with the arguments/lookup functions that the user would need to use and inject themselves?

Can you please share some code to illustrate your problem?