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 = [[
TOC
]] % {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
-- 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 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 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