On Saturday, 16 July 2022 at 18:17:53 UTC+5:30 Albert Krewinkel wrote:

Abhishek Ulayil <abhim...@gmail.com> writes:

> I was working on a lua filter to change the Table caption to add
> numbering
>
> ```
> tables = 0
> function Table(el)
> tables = tables + 1
> local caption = "Table " .. tostring(tables) .. ": " ..
> pandoc.utils.stringify(el.caption)
> print(caption)
>
> el.caption = caption --facing problem here
> return el
> end
> ```
>
> I am facing a problem to set the caption back to the element,
>
> what will be the correct way to set the caption.

Captions consist of two parts, the normal (long) caption and a shorter
(short) description that can be used in a list of tables, for example.
The problematic line should be changed to

el.caption.long = caption

As you noticed, it's not very user-friendly though, and we should
definitely improve that.

You'll probably want to keep the markup in the caption. I'm attaching a
version that's a bit longer, but will preserve the caption's markup.

HTH!

```
tables = 0
function Table(el)
tables = tables + 1
local label = pandoc.Inlines("Table " .. tostring(tables))
local caption = el.caption.long
if not caption[1] then
-- Table has no caption, just add the label
caption = pandoc.Blocks{label}
elseif caption[1].tag == 'Plain' or caption[1].tag == 'Para' then
-- Prepend label to paragraph
label:extend{pandoc.Str ':', pandoc.Space()}
caption[1].content = label .. caption[1].content
else
-- Add label as plain block element
label:extend{pandoc.Str ':', pandoc.Space()}
caption:insert(1, pandoc.Plain(label))
end

el.caption.long = caption
return el
end
```