Lua filters: "string expected, got Inline" for pandoc.Div

[l1mey112]

I have this code in a Lua filter:

function Image(el)

	if el.classes:includes('png_full') then
		el.src = resolve_url(el.src)
		
		el.attributes["style"] = "border: none;"
		el.attributes["loading"] = "lazy"

		-- line 27 below
		return pandoc.Div(
			{ el },
			{ style = "text-align: center;" }
		)
	end
	
	return el
end

Running this code, I get:

string expected, got Inline
stack traceback:
        tools/resources.lua:27: in function 'Image'

Is this not the indended use of pandoc.Div ? I simply want to replace all mentions of an image tag with the png_full class with something similar to the below:

<div style="text-align: center;">
<img loading="lazy" style="border: none;" src="$resolved_source$"></img>
</div>

[jgm]

Image is an Inline element, while Div is a Block element. You can't replace an Inline with a Block; the types don't match. (I'm not sure why this precise error message was produced, though. @tarleb may be able to clarify.)

[jgm]

In your case, if you only care about HTML, you can add the needed tags using RawInline elements.

[l1mey112]

I appreciate it. Are you suggesting doing something like:

-- Adjust the below, but you get it
return pandoc.RawInline("html", "
<div style="text-align: center;">
<img loading="lazy" style="border: none;" src="$resolved_source$"></img>
</div>
")

I assume in this case the types would match up.

[jgm]

yes

[tarleb]

About the error: this is probably due to resolve_url returning an Inlines value instead of a string. The error reporting for that should be improved.