2025-01-12 04:36:52 +08:00

525 lines
13 KiB
Lua

-- Table to store footnotes, so they can be included at the end.
local notes = {}
-- Rendering state
local in_slide = false
local build_slide = false
local in_notes = false
-- Character escaping
local function escape(s, in_attribute)
s = s:gsub("[<>&\"']",
function(x)
if x == '<' then
return '&lt;'
elseif x == '>' then
return '&gt;'
elseif x == '&' then
return '&amp;'
elseif x == '"' then
return '&quot;'
elseif x == "'" then
return '&#39;'
else
return x
end
end)
return s
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
-- Helper function to split a string on spaces
-- returns a table
local function split(str)
local words = {}
for word in str:gmatch("%S+") do table.insert(words, word) end
return words
end
-- Helper function to remove duplicates
-- returns a table http://stackoverflow.com/a/20067270
local function uniq(t)
local seen = {}
local res = {}
for _,v in ipairs(t) do
if (not seen[v]) then
res[#res+1] = v
seen[v] = true
end
end
return res
end
-- Helper function to filter a list
-- returns a table
local function grep(f, l)
local res = {}
for _,v in ipairs(l) do
if (f(v)) then
res[#res+1] = v
end
end
return res
end
-- Blocksep is used to separate block elements.
function Blocksep()
return "\n\n"
end
local function CompleteSlide()
if (in_slide) then
in_slide = false
return "</article></slide>"
else
return ""
end
end
-- This function is called once for the whole document. Parameters:
-- body is a string, metadata is a table, 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, metadata, variables)
-- complete any active slide
local suffix = CompleteSlide()
return body .. suffix
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)
s = escape(s)
if smart then
s = s:gsub("%-%-%-", "&#8212;")
s = s:gsub("%-%-", "&#8211;")
s = s:gsub("%.%.%.", "&#8230;")
end
return s
end
function Space()
return " "
end
function LineBreak()
return "<br/>"
end
function SoftBreak()
return " "
end
function Emph(s)
return "<em>" .. s .. "</em>"
end
function Underline(s)
return "<u>" .. s .. "</u>"
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 SingleQuoted(s)
if smart then
return '&lsquo;' .. s .. '&rsquo;'
else
return '"' .. s .. '"'
end
end
function DoubleQuoted(s)
if smart then
return '&ldquo;' .. s .. '&rdquo;'
else
return '"' .. s .. '"'
end
end
function Link(s, src, tit)
return "<a href='" .. escape(src,true) .. "' title='" ..
escape(tit,true) .. "'>" .. s .. "</a>"
end
function Image(s, src, tit, attr)
return "<img" .. attributes(attr) .. " src='" .. escape(src,true) .. "' title='" ..
escape(tit,true) .. "'/>"
end
function CaptionedImage(src, tit, s, attr)
local caption = ""
if fig_caption and (string.len(s) > 0) then
caption = "<p class='caption'>" .. s .. "</p>"
end
return Image(s, src, tit, attr) .. caption
end
function Code(s, attr)
return "<code" .. attributes(attr) .. ">" .. escape(s) .. "</code>"
end
function InlineMath(s)
s = escape(s)
if mathjax then
return "\\(" .. s .. "\\)"
else
return "$" .. s .. "$"
end
end
function DisplayMath(s)
s = escape(s)
if mathjax then
return "\\[" .. s .. "\\]"
else
return "$$" .. s .. "$$"
end
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 .. '">&#8617;</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 Span(s, attr)
return "<span" .. attributes(attr) .. ">" .. s .. "</span>"
end
function Cite(s)
return "<span class=\"cite\">" .. s .. "</span>"
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)
-- detect level 1 header and convert it to a segue slide
local slide_class = ""
local hgroup_class = ""
local slide_style = ""
-- make all headers < slide_level as segue slides
if lev < slide_level then
-- create a segue slide but add lev class for possible customization
slide_class = "segue dark nobackground" .. " level" .. lev
hgroup_class = " class = 'auto-fadein'"
lev = 2
end
-- support for slide specific image backgrounds
-- alternative is this css
-- slide > slide [data-slide-num="7"] {
-- background-image: url("figures/xx.jpg");
-- }
if attr["data-background"] then
-- dark is incompatible with fill and let us uniquify nobackground
local slide = split(slide_class .. " fill nobackground")
slide = grep(function (v)
if v:match("^dark$") then return false else return true end
end, slide)
slide_class = table.concat(uniq(slide), " ")
if attr["data-background"]:match("^#") then
slide_style = 'background: ' .. attr["data-background"] .. ';'
else
-- assume url
slide_style = 'background-image: url(' .. attr["data-background"] .. ');'
local bg_size = attr["data-background-size"]
if not bg_size then bg_size = "contain" end
slide_style = slide_style .. ' background-size: ' .. bg_size .. ';'
local bg_position = attr["data-background-position"]
if not bg_position then bg_position = "center" end
slide_style = slide_style .. ' background-position: ' .. bg_position .. ';'
end
-- remove noise attributes for article
attr["data-background"] = nil
attr["data-background-size"] = nil
attr["data-background-position"] = nil
end
-- extract optional subtitle
local subtitle = ""
if lev == 2 then
local i, j = string.find(s, "|")
if i then
subtitle = string.sub(s, i+1, string.len(s))
s = string.sub(s, 1, i-1)
end
end
-- trick: as lev value 2 is used in code below to start a new slide
-- we force all lev <= slide_level as new slides
if lev > 2 and lev <= slide_level then
lev = 2
end
-- build slide header (including optional subtitle)
local header = "<h" .. lev .. ">" .. s .. "</h" .. lev .. ">"
if string.len(subtitle) > 0 then
header = header .. "<h3>" .. subtitle .. "</h3>"
end
-- treat level 2 headers as slides
if lev == 2 then
-- complete previous slide
local preface = CompleteSlide()
-- start a new slide
in_slide = true
-- update build flag (used by ol and ul)
if attr["class"] and string.find(attr["class"], "build") then
build_slide = true
else
build_slide = false
end
-- add 'smaller' class if it was globally specified
if smaller then
if (attr["class"]) then
attr["class"] = "smaller " .. attr["class"]
else
attr["class"] = "smaller"
end
end
if string.len(slide_style) > 0 then
slide_style = ' style="' .. slide_style .. '"'
end
-- return the beginning of the slide
return preface .. "<slide class=\"" .. slide_class .. "\"" .. slide_style .. ">" ..
"<hgroup" .. hgroup_class .. ">" .. header .. "</hgroup>" ..
"<article " .. attributes(attr) .. ">"
else
return header
end
end
function BlockQuote(s)
-- if this is a list then blockquote means invert the default
-- incremental behavior
local prefix = string.sub(s, 1, 3)
if prefix == "<ol" or prefix == "<ul" then
if not incremental then
s = s:gsub(prefix .. ">", prefix .. " class = 'build'>", 1)
else
s = s:gsub(prefix .. " class = 'build'>", prefix .. ">", 1)
end
return s
else
return "<blockquote>\n" .. s .. "\n</blockquote>"
end
end
function HorizontalRule()
return Header(2, "", {})
end
function CodeBlock(s, attr)
-- if this code block has a class then add prettyprint to it
local class_attrib = ''
if attr["class"] then
local class = attr["class"]
if string.len(class) > 0 then
class_attrib = "class = 'prettyprint lang-" .. class .. "'"
end
end
-- substitute for code highlighting/emphasis
local code = escape(s)
code_sub = code:gsub("[ \t]*[#/]+[ \t]*&lt;b&gt;[ \t]*\n", "<b>")
code = code_sub:gsub("[ \t]*[#/]+[ \t]*&lt;/b&gt;[ \t]*\n", "</b>")
code = code:gsub("[ \t]*[#/]+[ \t]*&lt;/b&gt;[ \t]*$", "</b>")
return "<pre " .. class_attrib .. ">" .. code .. "</pre>"
end
function BulletList(items)
local buffer = {}
for _, item in pairs(items) do
table.insert(buffer, "<li>" .. item .. "</li>")
end
list_class = ""
if incremental then
list_class = " class = 'build'"
end
return "<ul" .. list_class .. ">\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
list_class = ""
if incremental then
list_class = " class = 'build'"
end
return "<ol" .. list_class .. ">\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 class = 'rmdtable'>")
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("%f%%", 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
function Div(s, attr)
if attr["class"] == "notes" then
return "<aside class='note'><section>" .. s ..
"</section></aside>"
else
return "<div" .. attributes(attr) .. ">\n" .. s .. "</div>"
end
end
function Span(s, attr)
return "<span" .. attributes(attr) .. ">\n" .. s .. "</span>"
end
function RawInline(f, s)
if f == "html" then
return s
else
return ''
end
end
function RawBlock(f, s)
if f == "html" then
return s
else
return ''
end
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)