diff options
| author | John MacFarlane <fiddlosopher@gmail.com> | 2013-04-02 21:08:38 -0700 |
|---|---|---|
| committer | John MacFarlane <jgm@berkeley.edu> | 2013-04-14 00:31:39 -0500 |
| commit | 4fa2a947590f78160dac3197672e475f433f0e4f (patch) | |
| tree | 658c4e6ec08ce1cf3dc4217d61dd1fb6c75cb656 /data | |
| parent | dede39452f9488002daa1b402eed8d25aa88994f (diff) | |
Added `Text.Pandoc.Writers.Custom`, `--print-custom-lua-writer`.
pandoc -t data/sample.lua
will load the script sample.lua and use it as a custom writer.
data/sample.lua is provided as an example.
Added `--print-custom-lua-writer` option to print the sample
script.
Diffstat (limited to 'data')
| -rw-r--r-- | data/sample.lua | 312 |
1 files changed, 312 insertions, 0 deletions
diff --git a/data/sample.lua b/data/sample.lua new file mode 100644 index 000000000..fe425b749 --- /dev/null +++ b/data/sample.lua @@ -0,0 +1,312 @@ +-- This is a sample custom writer for pandoc. It produces output +-- that is very similar to that of pandoc's HTML writer. +-- There is one new feature: code blocks marked with class 'dot' +-- are piped through graphviz and images are included in the HTML +-- output using 'data:' URLs. +-- +-- Invoke with: pandoc -t sample.lua +-- +-- Note: you need not have lua installed on your system to use this +-- custom writer. However, if you do have lua installed, you can +-- use it to test changes to the script. 'lua sample.lua' will +-- produce informative error messages if your code contains +-- syntax errors. + +-- Character escaping +local function escape(s, in_attribute) + return s:gsub("[<>&\"']", + function(x) + if x == '<' then + return '<' + elseif x == '>' then + return '>' + elseif x == '&' then + return '&' + elseif x == '"' then + return '"' + elseif x == "'" then + return ''' + else + return x + end + end) +end + +-- Helper function to convert an attributes table into +-- a string that can be put into HTML tags. +local function attributes(attr) + local attr_table = {} + for x,y in pairs(attr) do + if y and y ~= "" then + table.insert(attr_table, ' ' .. x .. '="' .. escape(y,true) .. '"') + end + end + return table.concat(attr_table) +end + +-- Run cmd on a temporary file containing inp and return result. +local function pipe(cmd, inp) + local tmp = os.tmpname() + local tmph = io.open(tmp, "w") + tmph:write(inp) + tmph:close() + local outh = io.popen(cmd .. " " .. tmp,"r") + local result = outh:read("*all") + outh:close() + os.remove(tmp) + return result +end + +-- Table to store footnotes, so they can be included at the end. +local notes = {} + +-- Blocksep is used to separate block elements. +function Blocksep() + return "\n\n" +end + +-- This function is called once for the whole document. Parameters: +-- body, title, date are strings; authors is an array of strings; +-- variables is a table. One could use some kind of templating +-- system here; this just gives you a simple standalone HTML file. +function Doc(body, title, authors, date, variables) + local buffer = {} + local function add(s) + table.insert(buffer, s) + end + add('<!DOCTYPE html>') + add('<html>') + add('<head>') + add('<title>' .. title .. '</title>') + add('</head>') + add('<body>') + if title ~= "" then + add('<h1 class="title">' .. title .. '</h1>') + end + for _, author in pairs(authors) do + add('<h2 class="author">' .. author .. '</h2>') + end + if date ~= "" then + add('<h3 class="date">' .. date .. '</h3>') + end + add(body) + if #notes > 0 then + add('<ol class="footnotes">') + for _,note in pairs(notes) do + add(note) + end + add('</ol>') + end + add('</body>') + add('</html>') + return table.concat(buffer,'\n') +end + +-- The functions that follow render corresponding pandoc elements. +-- s is always a string, attr is always a table of attributes, and +-- items is always an array of strings (the items in a list). +-- Comments indicate the types of other variables. + +function Str(s) + return escape(s) +end + +function Space() + return " " +end + +function LineBreak() + return "<br/>" +end + +function Emph(s) + return "<em>" .. s .. "</em>" +end + +function Strong(s) + return "<strong>" .. s .. "</strong>" +end + +function Subscript(s) + return "<sub>" .. s .. "</sub>" +end + +function Superscript(s) + return "<sup>" .. s .. "</sup>" +end + +function SmallCaps(s) + return '<span style="font-variant: small-caps;">' .. s .. '</span>' +end + +function Strikeout(s) + return '<del>' .. s .. '</del>' +end + +function Link(s, src, tit) + return "<a href='" .. escape(src,true) .. "' title='" .. + escape(tit,true) .. "'>" .. s .. "</a>" +end + +function Image(s, src, tit) + return "<img src='" .. escape(src,true) .. "' title='" .. + escape(tit,true) .. "'/>" +end + +function Code(s, attr) + return "<code" .. attributes(attr) .. ">" .. escape(s) .. "</code>" +end + +function InlineMath(s) + return "\\(" .. escape(s) .. "\\)" +end + +function DisplayMath(s) + return "\\[" .. escape(s) .. "\\]" +end + +function Note(s) + local num = #notes + 1 + -- insert the back reference right before the final closing tag. + s = string.gsub(s, + '(.*)</', '%1 <a href="#fnref' .. num .. '">↩</a></') + -- add a list item with the note to the note table. + table.insert(notes, '<li id="fn' .. num .. '">' .. s .. '</li>') + -- return the footnote reference, linked to the note. + return '<a id="fnref' .. num .. '" href="#fn' .. num .. + '"><sup>' .. num .. '</sup></a>' +end + +function Plain(s) + return s +end + +function Para(s) + return "<p>" .. s .. "</p>" +end + +-- lev is an integer, the header level. +function Header(lev, s, attr) + return "<h" .. lev .. attributes(attr) .. ">" .. s .. "</h" .. lev .. ">" +end + +function BlockQuote(s) + return "<blockquote>\n" .. s .. "\n</blockquote>" +end + +function HorizontalRule() + return "<hr/>" +end + +function CodeBlock(s, attr) + -- If code block has class 'dot', pipe the contents through dot + -- and base64, and include the base64-encoded png as a data: URL. + if attr.class and string.match(' ' .. attr.class .. ' ',' dot ') then + local png = pipe("base64", pipe("dot -Tpng", s)) + return '<img src="data:image/png;base64,' .. png .. '"/>' + -- otherwise treat as code (one could pipe through a highlighter) + else + return "<pre><code" .. attributes(attr) .. ">" .. escape(s) .. + "</code></pre>" + end +end + +function BulletList(items) + local buffer = {} + for _, item in pairs(items) do + table.insert(buffer, "<li>" .. item .. "</li>") + end + return "<ul>\n" .. table.concat(buffer, "\n") .. "\n</ul>" +end + +function OrderedList(items) + local buffer = {} + for _, item in pairs(items) do + table.insert(buffer, "<li>" .. item .. "</li>") + end + return "<ol>\n" .. table.concat(buffer, "\n") .. "\n</ol>" +end + +-- Revisit association list STackValue instance. +function DefinitionList(items) + local buffer = {} + for _,item in pairs(items) do + for k, v in pairs(item) do + table.insert(buffer,"<dt>" .. k .. "</dt>\n<dd>" .. + table.concat(v,"</dd>\n<dd>") .. "</dd>") + end + end + return "<dl>\n" .. table.concat(buffer, "\n") .. "\n</dl>" +end + +-- Convert pandoc alignment to something HTML can use. +-- align is AlignLeft, AlignRight, AlignCenter, or AlignDefault. +function html_align(align) + if align == 'AlignLeft' then + return 'left' + elseif align == 'AlignRight' then + return 'right' + elseif align == 'AlignCenter' then + return 'center' + else + return 'left' + end +end + +-- Caption is a string, aligns is an array of strings, +-- widths is an array of floats, headers is an array of +-- strings, rows is an array of arrays of strings. +function Table(caption, aligns, widths, headers, rows) + local buffer = {} + local function add(s) + table.insert(buffer, s) + end + add("<table>") + if caption ~= "" then + add("<caption>" .. caption .. "</caption>") + end + if widths and widths[1] ~= 0 then + for _, w in pairs(widths) do + add('<col width="' .. string.format("%d%%", w * 100) .. '" />') + end + end + local header_row = {} + local empty_header = true + for i, h in pairs(headers) do + local align = html_align(aligns[i]) + table.insert(header_row,'<th align="' .. align .. '">' .. h .. '</th>') + empty_header = empty_header and h == "" + end + if empty_header then + head = "" + else + add('<tr class="header">') + for _,h in pairs(header_row) do + add(h) + end + add('</tr>') + end + local class = "even" + for _, row in pairs(rows) do + class = (class == "even" and "odd") or "even" + add('<tr class="' .. class .. '">') + for i,c in pairs(row) do + add('<td align="' .. html_align(aligns[i]) .. '">' .. c .. '</td>') + end + add('</tr>') + end + add('</table') + return table.concat(buffer,'\n') +end + +-- The following code will produce runtime warnings when you haven't defined +-- all of the functions you need for the custom writer, so it's useful +-- to include when you're working on a writer. +local meta = {} +meta.__index = + function(_, key) + io.stderr:write(string.format("WARNING: Undefined function '%s'\n",key)) + return function() return "" end + end +setmetatable(_G, meta) + |