Re: Lua Filter: Get to parent of current element?

[Bastien DUMONT <bastien.dumont-VwIFZPTo/vqsTnJN9+BGXg@public.gmane.org>]

You cannot get directly the parent of an element, but you can use a particular filter on the content of an element. Here is an example that emphasize spans with class 'to-emphasize' in a BlockQuote in a particular way:

```
local spans_in_quote = {
  Span = function(span)
    if span.classes:includes('to-emphasize') then
      local _, pos = span.classes:find('to-emphasize')
      span.classes:remove(pos)
      return pandoc.Underline(span)
    end
  end
}

local function Span(span)
  if span.classes:includes('to-emphasize') then
    return pandoc.Emph(span)
  end
end

local function BlockQuote(quote)
  return quote:walk(spans_in_quote)
end

return {
  { BlockQuote = BlockQuote },
  { Span = Span }
}
```

The function BlockQuote is applied first and calls the filter spans_in_quote on the content of the BlockQuote. This filter transforms the Spans with the class 'to-emphasize' and remove that class so that it is not processed again by the Span function. After the BlockQuote function returns, the Span function is called on all Spans (including those inside the BlockQuote, that's why I removed the class 'to-emphasize'!).

Exemple of use:

pandoc -L test.lua <<< '
Normal [text]{.to-emphasize}.

> [Text]{.to-emphasize} in a quotation.

'
<p>Normal <em><span class="to-emphasize">text</span></em>.</p>
<blockquote>
<p><u><span>Text</span></u> in a quotation.</p>
</blockquote>

Le Wednesday 10 May 2023 à 06:02:18AM, ThomasH a écrit :
> Hi,
> 
> is there a way to get to the parent in the Pandoc AST from the current element
> in a Lua filter?
> I would like to distinguish treatment of elements depending on their context in
> the syntax tree, e.g. handle a 'span' element differently if it is a child of a
> 'cell' element in a table.
> 
> Thanks, T.
> 
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