There's a method ToHtmlContent that you can use to implement this without involving PocketView. PocketViewTags.HTML actually probably belongs with the methods under Microsoft.DotNet.Interactive.Kernel and the whole thing should probably move into Microsoft.DotNet.Interactive.Jupyter.

I'm not sure I follow. If in C# I do div("foo") that will call TryInvoke which internally just calls SetContent() and the body of that method does all of the fancy HTML escaping and encoding.

The ToHtmlContent() methods that I found only operate on string, so I don't know how I would apply that in the F# case. E.g.,

let content = "foo".ToHtmlContent() // this is now of the type `IHtmlContent`
div.<what_do_I_put_here_so_that_I_can_pass_in_content_from_above>(content)

This is made doubly difficult in that F# doesn't have dynamic and we're so strongly typed that it's sometimes painful.

My comment was only about the HTML method, which is unrelated to PocketView, and doesn't require dynamic.

    public static IHtmlContent HTML(string content) => content.ToHtmlContent();

Can you give an example? Do you mean this?

-default __.HTML content =
-    p.SetContent([|content|])
+default __.HTML (content: string) =
+    p.SetContent([|content.ToHtmlContent()|])

I'm suggesting we remove HTML from PocketViewTags and move it to someplace where it can be called directly from F# submissions. It doesn't need an F# wrapper or alternate implementation. It belongs in the same class with display and Javascript.

Ah, I think I see the confusion.

I'm simply trying to get around the fact that an F# object can't be directly invoked. E.g., this doesn't work:

div.["class", "c"]("body")
//                ^^^^^^^^ this fails because
//  ^^^^^^^^^^^^^^         this isn't a function

So we have to have an actual function that can be invoked:

div.["class", "c"].HTML("body")
//                 ^^^^ this IS a function and it CAN be invoked

Originally I called this innerHTML to mimic the HTML DOM, but then I found HTML() on PocketViewTags and thought I'd mimic that. Ultimately I don't care what this is called; the only restriction is that it has to exist.

Is there a name you'd prefer, or is HTML (or innerHTML) fine?

Quick edit:

The display and Javascript methods you mentioned feel like the wrong place for this, at least for F#, because the API would look like this and it feels clunky:

a.["href", "bing.com"].HTML("Click for bing!") // this is the current state in this PR
content(a.["href", "bing.com"], "Click for bing!") // this feels terrible
a.["href", "bing.com"].content("Click for bing!") // having `content` be an extension method feels acceptable, see below

If content() is an extension method then the API would have to look like this to be consumable by F#:

public static object content(this FSharpPocketViewTags tags, object body)
{
    tags.somehow_we_get_access_to_the_underlying_PocketView_value.SetContent(body);
}

And if we need an explicit overload just for F#, I'd rather leave it as it is in this PR; a dedicated method directly tied to the FSharpPocketViewTags class.

Spoke offline with @jonsequitur and @TIHan and long story short I mis-read the meaning of the HTML() method. To try to make the meaning clear I'm copying the DOM method name innerHTML().

There were other discussions about utilizing a constructor to set the inner content, but that opens a whole new can of worms around using the helper effectively.