module(...,package.seeall)
local eb = require("tex4ebook-exec_epub")
local dom = require("luaxml-domobject")
local log = logging.new "exec_epub3"
local ext = "xhtml"
local outputdir = nil
local input = nil
function prepare(params)
local basedir = params.input.."-".. params.format
local outputdir_name="OEBPS"
outputdir= basedir.."/"..outputdir_name
input = params.input
params.ext = ext
params.tex4ht_sty_par = params.tex4ht_sty_par .. ",html5"
params.packages = params.packages .. string.format("\\Configure{ext}{%s}",ext)
return eb.prepare(params)
end
function run(out,params)
return eb.run(out, params)
end
local function makeTOC(document)
local template = [[
<!DOCTYPE html>
<html xmlns="
http://www.w3.org/1999/xhtml"
xmlns:epub="
http://www.idpf.org/2007/ops"
xml:lang="en" lang="en"
>
<head><title>TOC</title></head>
<body>
<nav id="pub-toc" epub:type="toc" role="doc-toc">
<h1>Table of contents</h1>
<ol class="toc" hidden="hidden">
<li>
<a href="${document}">Document</a>
</li>
</ol>
</nav>
</body>
</html>
]] % {document=document}
return template
end
local function add_media_overlays(content)
local add_meta = function(package, attributes, text)
local meta = package:create_element("meta",attributes)
local dur_el = meta:create_text_node(text)
meta:add_child_node(dur_el)
package:add_child_node(meta)
end
-- calculate total audio time
local calc_times = function(times)
local time = 0
for _, curr in ipairs(times) do
-- smil file contains timestamps in the H:M:S format, we need to parse it
local hours, minutes, seconds = curr:match("(%d+):(%d+):(%d+)")
time = time + os.time({year=1970, day=1, month=1, hour=hours, min=minutes, sec=seconds})
end
return os.date("%H:%M:%S",time)
end
-- the second parameter for parse is table with void elements. the OPF format has no
-- void elements, so it needs to be empty, otherwise we may get parsing error because of
-- <meta> element, which is included in the default void elements
local opfdom = dom.parse(content, {})
local items = opfdom:query_selector("manifest item")
local ref = {}
local times = {}
local package = opfdom:query_selector("metadata")[1]
-- we must read all smil files and find references to html files
-- it is necessary to add media-overlay attribute to the referenced items
for _, item in ipairs(items) do
local href = item:get_attribute("href")
ref[href] = item
-- we must read audio length from the smil file and add it as a <meta> property
if href:match("smil$") then
local f = io.open(outputdir .. "/" .. href, "r")
if not f then break end
local smil = f:read("*all")
f:close()
local smildom = dom.parse(smil)
local audios = smildom:query_selector("audio")
local last = audios[#audios]
-- add audio duration to the metadata section
if last then
local duration = last:get_attribute("clipend")
if duration then
-- todo: calculate total audio length
table.insert(times, duration)
local audio_id = item:get_attribute("id")
add_meta(package, {property="media:duration", refines="#"..audio_id}, duration)
end
end
-- add the media-overlay attribute
local textref = smil:match('epub:textref="(.-)"')
local id = item:get_attribute("id")
local referenced = ref[textref]
if referenced then
referenced:set_attribute("media-overlay", id)
end
end
end
-- calculate length of all media overlay audio files
if #times > 0 then
local totaltime = calc_times(times)
add_meta(package,{property="media:duration"}, totaltime)
end
local serialized = opfdom:serialize()
return serialized
end
-- elements that shouldn't be put inside <a> in TOC
local stop_toc_processing_elements = {
ol = true,
ul = true
}
local function remove_spurious_TOC_elements(tocdom)
local function count_child_elements(el)
-- count children elements of the current element
local count = 0
for _, curr_el in ipairs(el:get_children()) do
if curr_el:is_element() then count = count + 1 end
end
return count
end
-- modify the TOC to comply to epubcheck tests
-- add a blank <li> to empty <ol>
for _, el in ipairs(tocdom:query_selector("ol")) do
if count_child_elements(el) == 0 then
el:remove_node()
end
end
-- place child elements of the <li> elements to an <a> element, epubcheck reports
-- error for text nodes that are direct child of <li>
for _, el in ipairs(tocdom:query_selector("li")) do
local newa = el:create_element("a")
local newchildren = {newa}
-- we want to stop putting content as child of <a> when it
-- finds child TOC entries
local keep_processing = true
for i, child in ipairs(el._children) do
child_name = child:get_element_name()
-- put contents of <li> to a new <a> element
if child:is_element() and child_name == "a" then
-- set id and href of the new <a> element, if it isn't set already
if not newa:get_attribute("href") then
local id = child:get_attribute("id")
local href = child:get_attribute("href")
newa:set_attribute("id", id)
newa:set_attribute("href", href)
end
-- copy <a> contents to the new <a> element
for _, x in ipairs(child._children or {}) do newa:add_child_node(x:copy_node()) end
elseif stop_toc_processing_elements[child_name] then
-- don't put child toc entries to the new <a>
keep_processing = false
newchildren[#newchildren+1] = child
elseif keep_processing == true then
-- put every node before <ol> or <ul> into the new <a>
newa:add_child_node(child:copy_node())
else
newchildren[#newchildren+1] = child
end
end
-- set contents of <li> to be the new <a>
el._children = newchildren
end
return tocdom
end
local function cleanTOC(content)
-- remove spurious empty elements from the TOC, to make epubcheck happy
-- find the file with TOC ("properties" attribute set to "nav"
local opfdom = dom.parse(content,{})
for _,item in ipairs(opfdom:query_selector("item")) do
local properties = item:get_attribute("properties") or ""
if properties:match("nav") then
local filename = item:get_attribute("href")
if filename then
filename = outputdir .. "/" .. filename
local f = io.open(filename, "r")
if not f then
log:warning("Cannot open TOC file for clean-up: " .. filename)
return nil
end
local t = f:read("*all")
f:close()
local tocdom = dom.parse(t)
tocdom = remove_spurious_TOC_elements(tocdom)
f = io.open(filename,"w")
f:write(tocdom:serialize())
f:close()
end
end
end
end
local function fix_properties(content)
-- some properties should be used only in the <spine> element, so we need to move them
-- here from the <manifest> section
-- because why it should be easy, when you can just make messy specification
-- and of course my old code is extremely messy as well.
if content:match("page%-spread%-") or content:match("rendition") then
local spread_ids = {}
local opfdom = dom.parse(content,{})
local update_properties = function(id, s)
local current_val = spread_ids[id] or {}
current_val[#current_val + 1] = s
spread_ids[id] = current_val
return ""
end
for _,item in ipairs(opfdom:query_selector("manifest item")) do
local properties = item:get_attribute "properties"
if properties then
local id = item:get_attribute "id"
properties = properties:gsub("(page%-spread%-[^%s]+)", function(s) return update_properties(id,s) end)
properties = properties:gsub("(rendition%:[^%s]+)", function(s) return update_properties(id,s) end)
-- properties attribute cannot be empty, we must disable it if
-- it doesn't contain anything after removing of the page spread
if properties:match("^%s*$") then properties = nil
end
item:set_attribute("properties", properties)
end
end
for _, item in ipairs(opfdom:query_selector("spine itemref")) do
local idref = item:get_attribute("idref")
local spread = spread_ids[idref]
if spread then
item:set_attribute("properties", table.concat(spread, " "))
end
end
return opfdom:serialize()
end
return content
end
local function cleanOPF()
-- in epub3, there must be table of contents
-- if there is no toc in the document, we must add generic one
local opf = "content.opf"
local f = io.open(opf,"r")
if not f then
log:info("Cannot open "..opf .. " for toc searching")
return nil
end
local content = f:read("*all")
f:close()
if content:find "properties[%s]*=[%s]*\"[^\"]*nav" then
log:info "TOC nav found"
cleanTOC(content)
else
log:info "no TOC, using a generic one"
local inputfile = input .. "." .. ext
log:info("Main file name: ".. inputfile)
-- write toc file
local toc_name = "generic_toc" .."."..ext
local f = io.open(outputdir .. "/" .. toc_name, "w")
f:write(makeTOC(inputfile))
f:close()
-- add toc file to the conten.opf
content = content:gsub("<manifest>","<manifest>\n<item id='htmltoc'" ..
" properties=\"nav\" media-type=\"application/xhtml+xml\" href=\""..
toc_name .."\" />\n")
-- we shouldn't add the TOC to the spine, because it is not linear and not linked from anywhere,
-- resulting in error in EpubCheck
-- content = content:gsub("<spine([^>]*)>", "<spine%1>\n<itemref idref=\"htmltoc\" linear=\"no\"/>\n")
end
-- remove empty guide element
content = eb.remove_empty_guide(content)
content = add_media_overlays(content)
content = fix_properties(content)
f = io.open(outputdir .. "/" ..opf,"w")
f:write(content)
f:close()
--makeTOC(inputfile)
end
function writeContainer()
--local ret = eb.writeContainer()
log:info "write container"
eb.make_opf()
cleanOPF()
eb.clean_xml_files()
local ret = eb.pack_container()
return ret
end
function clean()
return eb.clean()
end
