if PANDOC_VERSION and PANDOC_VERSION.must_be_at_least then – Actually, this check is redundant since `Version’ objects were – introduced in pandoc v2.7.3, but I’ve left it in for clarity. PANDOC_VERSION:must_be_at_least(“2.7.3”) else error(“pandoc version >=2.7.3 is required”) end
-local OPTIONS = { image_directory = “.” }
-local SPECIAL_CLASSES = { [“lilypond”] = true, [“ly-fragment”] = true, [“ly-norender”] = true }
-local SPECIAL_ATTRIBUTES = { [“ly-caption”] = true, [“ly-name”] = true, [“ly-resolution”] = true, [“ly-title”] = true }
-– pandoc.system.with_temporary_directory had a different (undocumented) – name in the 2.7.3 release. local with_temporary_directory = tostring(PANDOC_VERSION) == “2.7.3” and pandoc.system.with_temp_directory or pandoc.system.with_temporary_directory
-– This is the extra boilerplate that’s added to code snippets when the –ly-fragment' class is present. It's adapted from whatlilypond-book’ – does. (The file `lilypond-book-preamble.ly’ is placed on the include – path as part of the default LilyPond installation.) local function wrap_fragment(src) return table.concat( { [[
-“lilypond-book-preamble.ly”]], [[]], src, }, “” ) end
-local function generate_image(name, input, dpi) local fullname = name .. “.png” return fullname, with_temporary_directory( “lilypond-lua-XXXXX,” function (tmp_dir) return pandoc.system.with_working_directory( tmp_dir, function () pandoc.pipe( “lilypond,” { “–silent,” “–png,” dpi and “-dresolution=” .. dpi or "“,”–output=" .. name, “-” }, input ) local fh = io.open(fullname, ‘rb’) local data = fh:read(’*all’) fh:close() return data end ) end ) end
-local function process_lilypond(elem, inline) local code = elem.text local fragment = elem.classes:includes(“ly-fragment”) or inline local input = fragment and wrap_fragment(code) or code local dpi = elem.attributes[“ly-resolution”] local name = elem.attributes[“ly-name”] or pandoc.sha1(code)
-local image_filename, image_data = generate_image(name, input, dpi) local src = OPTIONS.image_directory .. ‘/’ .. image_filename pandoc.mediabag.insert(src, “image/png,” image_data)
-local caption = elem.attributes[“ly-caption”] or “Musical notation” – The “fig:” prefix causes this image to be rendered as a proper figure – in HTML ouput (this is a rather ugly pandoc feature and may be replaced – by something more elegant in the future). local fudge = inline and "" or “fig:” – Strip newlines, indendation, etc. from the code for a more readable title. local title = fudge .. (elem.attributes[“ly-title”] or code:gsub(“%s+,” " "))
-– Strip most of the LilyPond-related attributes from this code element, for – tidiness. local classes = elem.classes:filter( function (cls) return not SPECIAL_CLASSES[cls] end ) table.insert( classes, – Add one special class for styling/manipulation purposes. inline and “lilypond-image-inline” or “lilypond-image-standalone” ) local attributes = elem.attributes for a, t in pairs(SPECIAL_ATTRIBUTES) do attributes[a] = nil end local attrs = pandoc.Attr(elem.identifier, classes, attributes)
-return pandoc.Image(caption, src, title, attrs) end
-– Update `OPTIONS’ based on the document metadata. local function meta_transformer(md) local ly_block = md.lilypond or {} local dir_conf = ly_block.image_directory OPTIONS.image_directory = dir_conf and pandoc.utils.stringify(dir_conf) or OPTIONS.image_directory md.lilypond = nil return md end
-local function code_transformer(elem) if elem.classes:includes(“lilypond”) and not elem.classes:includes(“ly-norender”) then return process_lilypond(elem, true) else return elem end end
-local function code_block_transformer(elem) if elem.classes:includes(“lilypond”) and not elem.classes:includes(“ly-norender”) then – When replacing a block element we must wrap the generated image – in a Para' sinceImage’ is an inline element. return pandoc.Para({process_lilypond(elem, false)}) else return elem end end
– Make sure the metadata transformation runs first so that the code – transformations operate with the correct options. return { {Meta = meta_transformer}, {Code = code_transformer, CodeBlock = code_block_transformer}, }
- -