local JSON = require("json") local RenderImage = require("ui/renderimage") local Screen = require("device").screen local ffiutil = require("ffi/util") local lfs = require("libs/libkoreader-lfs") local logger = require("logger") local util = require("util") local _ = require("gettext") local T = ffiutil.template --[[ -- Query wikipedia using Wikimedia Web API. -- https://en.wikipedia.org/w/api.php?format=jsonfm&action=query&generator=search&gsrnamespace=0&gsrsearch=ereader&gsrlimit=10&prop=extracts&exintro&explaintext&exlimit=max -- https://en.wikipedia.org/w/api.php?action=query&prop=extracts&format=jsonfm&explaintext=&redirects=&titles=E-reader -- -- To get parsed HTML : -- https://en.wikipedia.org/w/api.php?action=parse&page=E-book -- https://en.wikipedia.org/w/api.php?action=parse&page=E-book&prop=text|sections|displaytitle|revid&disablelimitreport=&disableeditsection -- https://www.mediawiki.org/wiki/API:Parsing_wikitext#parse --]] local Wikipedia = { wiki_server = "https://%s.wikipedia.org", wiki_path = "/w/api.php", default_lang = "en", -- See https://www.mediawiki.org/wiki/API:Main_page for details. -- Search query, returns introductory texts (+ main thumbnail image) wiki_search_params = { action = "query", generator = "search", gsrnamespace = "0", -- gsrsearch = nil, -- text to lookup, will be added below gsrlimit = 20, -- max nb of results to get exlimit = "max", prop = "extracts|info|pageimages", -- 'extracts' to get text, 'info' to get full page length format = "json", explaintext = "", exintro = "", -- We have to use 'exintro=' to get extracts for ALL results -- (otherwise, we get the full text for only the first result, and -- no text at all for the others }, -- Full article, parsed to output text (+ main thumbnail image) wiki_full_params = { action = "query", prop = "extracts|pageimages", format = "json", -- exintro = nil, -- get more than only the intro explaintext = "", redirects = "", -- title = nil, -- text to lookup, will be added below }, -- Full article, parsed to output HTML, for Save as EPUB wiki_phtml_params = { action = "parse", format = "json", -- we only need the following informations prop = "text|sections|displaytitle|revid", -- page = nil, -- text to lookup, will be added below -- disabletoc = "", -- if we want to remove toc IN html disablelimitreport = "", disableeditsection = "", }, -- Full article, parsed to output HTML, for images extraction -- (used with full article as text, if "show more images" enabled) wiki_images_params = { -- same as previous one, with just text html action = "parse", format = "json", -- we only need the following informations prop = "text", -- page = nil, -- text to lookup, will be added below redirects = "", disabletoc = "", -- remove toc in html disablelimitreport = "", disableeditsection = "", }, -- There is an alternative for obtaining page's images: -- prop=imageinfo&action=query&iiprop=url|dimensions|mime|extmetadata&generator=images&pageids=49448&iiurlwidth=100&iiextmetadatafilter=ImageDescription -- but it gives all images (including wikipedia icons) in any order, without -- any score or information that would help considering if they matter or not -- -- Allow for disabling prettifying full page text wiki_prettify = G_reader_settings:nilOrTrue("wikipedia_prettify"), -- Can be set so HTTP requests will be done under Trapper and -- be interruptible trap_widget = nil, -- For actions done with Trapper:dismissable methods, we may throw -- and error() with this code. We make the value of this error -- accessible here so that caller can know it's a user dismiss. dismissed_error_code = "Interrupted by user", } function Wikipedia:getWikiServer(lang) return string.format(self.wiki_server, lang or self.default_lang) end -- Get URL content local function getUrlContent(url, timeout, maxtime) local http = require("socket.http") local ltn12 = require("ltn12") local socket = require("socket") local socketutil = require("socketutil") local socket_url = require("socket.url") local parsed = socket_url.parse(url) if parsed.scheme ~= "http" and parsed.scheme ~= "https" then return false, "Unsupported protocol" end if not timeout then timeout = 10 end local sink = {} socketutil:set_timeout(timeout, maxtime or 30) local request = { url = url, method = "GET", sink = maxtime and socketutil.table_sink(sink) or ltn12.sink.table(sink), } local code, headers, status = socket.skip(1, http.request(request)) socketutil:reset_timeout() local content = table.concat(sink) -- empty or content accumulated till now -- logger.dbg("code:", code) -- logger.dbg("headers:", headers) -- logger.dbg("status:", status) -- logger.dbg("#content:", #content) if code == socketutil.TIMEOUT_CODE or code == socketutil.SSL_HANDSHAKE_CODE or code == socketutil.SINK_TIMEOUT_CODE then logger.warn("request interrupted:", code) return false, code end if headers == nil then logger.warn("No HTTP headers:", status or code or "network unreachable") return false, "Network or remote server unavailable" end if not code or code < 200 or code > 299 then -- all 200..299 HTTP codes are OK logger.warn("HTTP status not okay:", status or code or "network unreachable") logger.dbg("Response headers:", headers) return false, "Remote server error or unavailable" end if headers and headers["content-length"] then -- Check we really got the announced content size local content_length = tonumber(headers["content-length"]) if #content ~= content_length then return false, "Incomplete content received" end end return true, content end function Wikipedia:setTrapWidget(trap_widget) self.trap_widget = trap_widget end function Wikipedia:resetTrapWidget() self.trap_widget = nil end -- Possible values for page_type parameter to loadPage() local WIKIPEDIA_INTRO = 1 local WIKIPEDIA_FULL = 2 local WIKIPEDIA_PHTML = 3 local WIKIPEDIA_IMAGES = 4 --[[ -- return decoded JSON table from Wikipedia --]] function Wikipedia:loadPage(text, lang, page_type, plain) local url = require("socket.url") local query = "" local parsed = url.parse(self:getWikiServer(lang)) parsed.path = self.wiki_path if page_type == WIKIPEDIA_INTRO then -- search query self.wiki_search_params.explaintext = plain and "" or nil for k,v in pairs(self.wiki_search_params) do query = string.format("%s%s=%s&", query, k, v) end parsed.query = query .. "gsrsearch=" .. url.escape(text) elseif page_type == WIKIPEDIA_FULL then -- full page content self.wiki_full_params.explaintext = plain and "" or nil for k,v in pairs(self.wiki_full_params) do query = string.format("%s%s=%s&", query, k, v) end parsed.query = query .. "titles=" .. url.escape(text) elseif page_type == WIKIPEDIA_PHTML then -- parsed html page content for k,v in pairs(self.wiki_phtml_params) do query = string.format("%s%s=%s&", query, k, v) end parsed.query = query .. "page=" .. url.escape(text) elseif page_type == WIKIPEDIA_IMAGES then -- images found in page html for k,v in pairs(self.wiki_images_params) do query = string.format("%s%s=%s&", query, k, v) end parsed.query = query .. "page=" .. url.escape(text) else return end local built_url = url.build(parsed) local completed, success, content if self.trap_widget then -- if previously set with Wikipedia:setTrapWidget() local Trapper = require("ui/trapper") local timeout, maxtime = 30, 60 -- We use dismissableRunInSubprocess with complex return values: completed, success, content = Trapper:dismissableRunInSubprocess(function() return getUrlContent(built_url, timeout, maxtime) end, self.trap_widget) if not completed then error(self.dismissed_error_code) -- "Interrupted by user" end else -- Smaller timeout than when we have a trap_widget because we are -- blocking without one (but 20s may be needed to fetch the main HTML -- page of big articles when making an EPUB). local timeout, maxtime = 20, 60 success, content = getUrlContent(built_url, timeout, maxtime) end if not success then error(content) end if content ~= "" and string.sub(content, 1, 1) == "{" then local ok, result = pcall(JSON.decode, content) if ok and result then logger.dbg("wiki result json:", result) return result else logger.warn("wiki result json decoding error:", result) error("Failed decoding JSON") end else logger.warn("wiki response is not json:", content) error("Response is not JSON") end end -- search wikipedia and get intros for results function Wikipedia:searchAndGetIntros(text, lang) local result = self:loadPage(text, lang, WIKIPEDIA_INTRO, true) if result then local query = result.query if query then local show_image = G_reader_settings:nilOrTrue("wikipedia_show_image") -- Scale wikipedia normalized (we hope) thumbnail by 2 (adjusted -- to screen size/dpi) for intros (and x8 more for highres image) local image_size_factor = Screen:scaleBySize(200)/100.0 if show_image then for pageid, page in pairs(query.pages) do self:addImages(page, lang, false, image_size_factor, 8) end end return query.pages end end end -- get full content of a wiki page function Wikipedia:getFullPage(wiki_title, lang) local result = self:loadPage(wiki_title, lang, WIKIPEDIA_FULL, true) if result then local query = result.query if query then local show_image = G_reader_settings:nilOrTrue("wikipedia_show_image") local show_more_images = G_reader_settings:nilOrTrue("wikipedia_show_more_images") -- Scale wikipedia normalized (we hope) thumbnails by 4 (adjusted -- to screen size/dpi) for full page (and this *4 for highres image) local image_size_factor = Screen:scaleBySize(400)/100.0 if self.wiki_prettify or show_image then for pageid, page in pairs(query.pages) do if self.wiki_prettify and page.extract then -- Prettification of the plain text full page page.extract = self:prettifyText(page.extract) end if show_image then self:addImages(page, lang, show_more_images, image_size_factor, 4) end end end return query.pages end end end -- get parsed html content and other infos of a wiki page function Wikipedia:getFullPageHtml(wiki_title, lang) local result = self:loadPage(wiki_title, lang, WIKIPEDIA_PHTML, true) if result and result.parse then return result.parse end if result.error and result.error.info then error(result.error.info) end end -- get images extracted from parsed html function Wikipedia:getFullPageImages(wiki_title, lang) local images = {} -- will be returned, each in a format similar to page.thumbnail local result = self:loadPage(wiki_title, lang, WIKIPEDIA_IMAGES, true) if result and result.parse and result.parse.text and result.parse.text["*"] then local html = result.parse.text["*"] -- html content local url = require('socket.url') local wiki_base_url = self:getWikiServer(lang) local thumbs = {} -- bits of HTML containing an image -- We first try to catch images in
, which should exclude -- wikipedia icons, flags... These seem to all end with a double
. for thtml in html:gmatch([[
%s*
]]) do table.insert(thumbs, thtml) end -- We then also try to catch images in galleries (which often are less -- interesting than those in thumbinner) as a 2nd set. for thtml in html:gmatch([[
  • %s*%s*
    .-
    %s*]]) do table.insert(thumbs, thtml) end -- We may miss some interesting images in the page's top right table, but -- there's no easy way to distinguish them from icons/flags in this table... for _, thtml in ipairs(thumbs) do -- We get )(.*)]]) if timg and tremain then -- (Should we discard those without caption ?) local caption = tremain and util.htmlToPlainText(tremain) if caption == "" then caption = nil end logger.dbg(" caption:", caption) -- logger.dbg(timg) local src = timg:match([[src="([^"]*)"]]) if src and src ~= "" then if src:sub(1,2) == "//" then src = "https:" .. src elseif src:sub(1,1) == "/" then -- non absolute url src = wiki_base_url .. src end local width = tonumber(timg:match([[width="([^"]*)"]])) local height = tonumber(timg:match([[height="([^"]*)"]])) -- Ignore img without width and height, which should exlude -- javascript maps and other unsupported stuff if width and height then -- Images in the html we got seem to be x4.5 the size of -- the thumbnail we get with searchAndGetIntros() or -- getFullPage(). Normalize them to the size of the thumbnail, -- so we can resize them all later with the same rules. width = math.ceil(width/4.5) height = math.ceil(height/4.5) -- No need to adjust width in src url here, as it will be -- done in addImages() anyway -- src = src:gsub("(.*/)%d+(px-[^/]*)", "%1"..width.."%2") logger.dbg(" size:", width, "x", height, "url:", src) table.insert(images, { source = src, width = width, height = height, filename = filename, caption = caption, }) end end end end end return images end -- Function wrapped and plugged to image objects returned by :addImages() local function image_load_bb_func(image, highres) local source, trap_widget if not highres then -- We use an invisible widget that will resend the dismiss event, -- so that image loading in TextBoxWdiget is unobtrusive and -- interruptible trap_widget = nil source = image.source else -- We need to let the user know image loading is happening, -- with a discreet TrapWidget trap_widget = _("Loading high-res image… (tap to cancel)") source = image.hi_source end -- Image may be big or take some time to be resized on wikipedia servers. -- As we use dismissableRunInSubprocess and can interrupt this loading, -- we can use quite high timeouts local timeout, maxtime = 60, 120 logger.dbg("fetching", source) local Trapper = require("ui/trapper") -- We use dismissableRunInSubprocess with simple string return value to -- avoid serialization/deserialization of a long string of image bytes local completed, data = Trapper:dismissableRunInSubprocess(function() local success, data = getUrlContent(source, timeout, maxtime) -- With simple string value, we're not able to return the failure -- reason, so log it here if not success then logger.warn("failed fetching image from", source, ":", data) end return success and data or nil end, trap_widget, true) -- task_returns_simple_string=true local success = data and true or false -- guess success from data if not completed then logger.dbg("image fetching interrupted by user") return true -- let caller know it was interrupted end if not success then -- log it again (on Android, log from sub-process seem to not work) logger.warn("failed fetching image from", source) return end logger.dbg(" fetched", #data) local bb if not highres then -- For low-res, we should ensure the image we got from wikipedia is -- the right size, so it does not overflow our reserved area -- (TextBoxWidget may have adjusted image.width and height) -- We don't get animated GIF multiple frames to keep TextBoxWidget -- simple: they will be available when viewed in highres bb = RenderImage:renderImageData(data, #data, false, image.width, image.height) else -- We provide want_frames=true for highres images, so ImageViewer -- can display animated GIF -- No need for width and height for high-res bb = RenderImage:renderImageData(data, #data, true) end if not bb then logger.warn("failed building image from", source) return end if not highres then image.bb = bb else image.hi_bb = bb end end function Wikipedia:addImages(page, lang, more_images, image_size_factor, hi_image_size_factor) -- List of images, table with keys as expected by TextBoxWidget page.images = {} -- List of wikipedia images data structures (page.thumbnail and images -- extracted from html) made to have the same keys for common processing local wimages = {} -- We got what Wikipedia scored as the most interesting image for this -- page in page.thumbnail, and its filename in page.pageimage, ie: -- "thumbnail": { -- "source": "https://upload.wikimedia.org/wikipedia/commons/thumb/4/45/Reading_on_the_bus_train_or_transit.jpg/37px-Reading_on_the_bus_train_or_transit.jpg", -- "width": 37, -- "height": 50 -- }, -- "pageimage": "Reading_on_the_bus_train_or_transit.jpg" -- local first_image_filename = nil if page.thumbnail and page.thumbnail.source then page.thumbnail.filename = page.pageimage first_image_filename = page.pageimage table.insert(wimages, page.thumbnail) end -- To get more images, we need to make a second request to wikipedia if more_images then local ok, images_or_err = pcall(Wikipedia.getFullPageImages, Wikipedia, page.title, lang) if not ok then logger.warn("error getting more images", images_or_err) else for _, wimage in ipairs(images_or_err) do if first_image_filename and wimage.filename == first_image_filename then -- We got the same image as the thumbnail one, but it may have -- a caption: replace thumbnail one with this one table.remove(wimages, 1) table.insert(wimages, 1, wimage) else table.insert(wimages, wimage) end end end end -- All our wimages now have the keys: source, width, height, filename, caption for _, wimage in ipairs(wimages) do -- We trust wikipedia, and our x4.5 factor in :getFullPageImages(), for adequate -- and homogeneous images' sizes. We'll just scale them according to the -- provided 'image_size_factor' (which should account for screen size/DPI) local width = wimage.width or 100 -- in case we don't get any width or height local height = wimage.height or 100 -- Give a little boost in size to thin images if width < height / 2 or height < width / 2 then width = math.floor(width * 1.3) height = math.floor(height * 1.3) end width = math.ceil(width * image_size_factor) height = math.ceil(height * image_size_factor) -- All wikipedia image urls like .../wikipedia/commons/A/BC/ -- or .../wikipedia/commons/thumb/A/BC//px- -- can be transformed to another url with a requested new_width with the form: -- /wikipedia/commons/thumb/A/BC//px- -- (Additionally, the image format can be changed by appending .png, -- .jpg or .gif to it) -- The resize is so done on Wikipedia servers from the source image for -- the best quality. local source = wimage.source:gsub("(.*/)%d+(px-[^/]*)", "%1"..width.."%2") -- We build values for a high resolution version of the image, to be displayed -- with ImageViewer (x 4 by default) local hi_width = width * (hi_image_size_factor or 4) local hi_height = height * (hi_image_size_factor or 4) local hi_source = wimage.source:gsub("(.*/)%d+(px-[^/]*)", "%1"..hi_width.."%2") local title = wimage.filename if title then title = title:gsub("_", " ") end local image = { -- As expected by TextBoxWidget (with additional source and -- hi_source, that will be used by load_bb_func) title = title, caption = wimage.caption, source = source, width = width, height = height, bb = nil, -- will be loaded and build only if needed hi_source = hi_source, hi_width = hi_width, hi_height = hi_height, hi_bb = nil, -- will be loaded and build only if needed } -- If bb or hi_bb is nil, TextBoxWidget will call a method named "load_bb_func" image.load_bb_func = function(highres) return image_load_bb_func(image, highres) end table.insert(page.images, image) end end -- UTF8 of unicode geometrical shapes we can use to replace -- the "=== title ===" of wkipedia plaintext pages -- These chosen ones are available in most fonts (prettier symbols -- exist in unicode, but are available in a few fonts only) and -- have a quite consistent size/weight in all fonts. local th1_sym = "\xE2\x96\x88" -- full block (big black rectangle) (never met, only for web page title?) local th2_sym = "\xE2\x96\x89" -- big black square local th3_sym = "\xC2\xA0\xE2\x97\xA4" -- black upper left triangle (indented, nicer) local th4_sym = "\xE2\x97\x86" -- black diamond local th5_sym = "\xE2\x9C\xBF" -- black florette local th6_sym = "\xE2\x9D\x96" -- black diamond minus white x -- Others available in most fonts -- local thX_sym = "\xE2\x9C\x9A" -- heavy greek cross -- local thX_sym = "\xE2\x97\xA2" -- black lower right triangle -- local thX_sym = "\xE2\x97\x89" -- fish eye -- local thX_sym = "\xE2\x96\x97" -- quadrant lower right -- For optional prettification of the plain text full page function Wikipedia:prettifyText(text) -- We use \a for an additional leading \n that we don't want shortened later text = text:gsub("\n= ", "\n\a"..th1_sym.." ") -- 2 empty lines before text = text:gsub("\n== ", "\n\a"..th2_sym.." ") -- 2 empty lines before text = text:gsub("\n=== ", "\n"..th3_sym.." ") text = text:gsub("\n==== ", "\n"..th4_sym.." ") text = text:gsub("\n===== ", "\n"..th5_sym.." ") text = text:gsub("\n====== ", "\n"..th6_sym.." ") text = text:gsub("Modifier ==", " ==") -- fr wikipedia fix for some articles modified by clumsy editors text = text:gsub("==$", "==\n") -- for a at end of text to be matched by next gsub text = text:gsub(" ===?\n+", "\n\n") -- to : empty line after text = text:gsub(" ====+\n+", "\n") -- to : single \n, no empty line text = text:gsub("\n\n+\xE2\x80\x94", "\n\xE2\x80\x94") -- em dash, used for quote author, make it stick to prev text text = text:gsub("\n +\n", "\n") -- trim lines full of only spaces (often seen in math formulas) text = text:gsub("^\n*", "") -- trim new lines at start text = text:gsub("\n*$", "") -- trim new lines at end text = text:gsub("\n\n+", "\n\n") -- shorten multiple new lines text = text:gsub("\a", "\n") -- re-add our wished \n return text end -- UTF8 of unicode geometrical shapes we'll prepend to wikipedia section headers, -- to help identifying hierarchy (othewise, the small font size differences helps). -- Best if identical to the ones used above for prettifying full plain text page. -- These chosen ones are available in most fonts (prettier symbols -- exist in unicode, but are available in a few fonts only) and -- have a quite consistent size/weight in all fonts. local h1_sym = "\xE2\x96\x88" -- full block (big black rectangle) (never met, only for web page title?) local h2_sym = "\xE2\x96\x89" -- big black square local h3_sym = "\xE2\x97\xA4" -- black upper left triangle local h4_sym = "\xE2\x97\x86" -- black diamond local h5_sym = "\xE2\x9C\xBF" -- black florette local h6_sym = "\xE2\x9D\x96" -- black diamond minus white x -- Other available ones in most fonts -- local hXsym = "\xE2\x9C\x9A" -- heavy greek cross -- local hXsym = "\xE2\x97\xA2" -- black lower right triangle -- local hXsym = "\xE2\x97\x89" -- fish eye -- local hXsym = "\xE2\x96\x97" -- quadrant lower right local ext_to_mimetype = { png = "image/png", jpg = "image/jpeg", jpeg = "image/jpeg", gif = "image/gif", webp = "image/webp", svg = "image/svg+xml", html= "application/xhtml+xml", xhtml= "application/xhtml+xml", ncx = "application/x-dtbncx+xml", js = "text/javascript", css = "text/css", otf = "application/opentype", ttf = "application/truetype", woff = "application/font-woff", } -- Display from these Wikipedia should be RTL -- The API looks like it does not give any info about the LTR/RTL -- direction of the content it returns... -- (list made by quickly and manually checking links from: -- https://meta.wikimedia.org/wiki/List_of_Wikipedias ) local rtl_wiki_code = { fa = "Persian", ar = "Arabic", he = "Hebrew", ur = "Urdu", azb = "South Azerbaijani", pnb = "Western Punjabi", ckb = "Sorani", arz = "Egyptian Arabic", yi = "Yiddish", sd = "Sindhi", mzn = "Mazandarani", ps = "Pashto", glk = "Gilaki", lrc = "Northern Luri", ug = "Uyghur", dv = "Divehi", arc = "Aramaic", ks = "Kashmiri", } function Wikipedia:isWikipediaLanguageRTL(lang) if lang and rtl_wiki_code[lang:lower()] then return true end return false end -- Create an epub file (with possibly images) function Wikipedia:createEpub(epub_path, page, lang, with_images) -- Use Trapper to display progress and ask questions through the UI. -- We need to have been Trapper.wrap()'ed for UI to be used, otherwise -- Trapper:info() and Trapper:confirm() will just use logger. local UI = require("ui/trapper") UI:info(_("Retrieving Wikipedia article…")) local ok, phtml = pcall(self.getFullPageHtml, self, page, lang) if not ok then UI:info(phtml) -- display error in InfoMessage -- Sleep a bit to make that error seen ffiutil.sleep(2) UI:reset() return false end -- We may need to build absolute urls for non-absolute links and images urls local wiki_base_url = self:getWikiServer(lang) -- Get infos from wikipedia result -- (see example at https://en.wikipedia.org/w/api.php?action=parse&page=E-book&prop=text|sections|displaytitle|revid&disablelimitreport=&disableeditsection) local cancelled = false local html = phtml.text["*"] -- html content local page_cleaned = page:gsub("_", " ") -- page title local page_htmltitle = phtml.displaytitle -- page title with possible tags -- We need to encode plain '&' in those so we can put them in XML/HTML -- We wouldn't need to escape as many as util.htmlEntitiesToUtf8() does, but -- we need to to not mess existing ones (' ' may happen) with our '&' -- encodes. (We don't escape < or > as these JSON strings may contain HTML tags) page_cleaned = util.htmlEntitiesToUtf8(page_cleaned):gsub("&", "&") page_htmltitle = util.htmlEntitiesToUtf8(page_htmltitle):gsub("&", "&") local sections = phtml.sections -- Wikipedia provided TOC local bookid = string.format("wikipedia_%s_%s_%s", lang, phtml.pageid, phtml.revid) -- Not sure if this bookid may ever be used by indexing software/calibre, but if it is, -- should it changes if content is updated (as now, including the wikipedia revisionId), -- or should it stays the same even if revid changes (content of the same book updated). -- We need to find images in HTML to tell how many when asking user if they should be included local images = {} local seen_images = {} local imagenum = 1 local cover_imgid = nil -- best candidate for cover among our images local processImg = function(img_tag) local src = img_tag:match([[src="([^"]*)"]]) if src == nil or src == "" then logger.info("no src found in ", img_tag) return nil end if src:sub(1,2) == "//" then src = "https:" .. src -- Wikipedia redirects from http to https, so use https elseif src:sub(1,1) == "/" then -- non absolute url src = wiki_base_url .. src end -- Some SVG urls don't have any extension, like: -- "/api/rest_v1/media/math/render/svg/154a342afea5a9f13caf1a5bb6acd5c4e69733b6"" -- Furthermore, as of early 2018, it looks like most (all?) mathematical SVG -- obtained from such urls use features not supported by crengine's nanosvg -- renderer (so, they are displayed as a blank square). -- But we can get a PNG version of it thanks to wikipedia APIs : -- https://wikimedia.org/api/rest_v1/#!/Math/get_media_math_render_format_hash -- We tweak the url now (and fix the mimetype below), before checking for -- duplicates in seen_images. -- As of mid 2022, crengine has switched from using NanoSVG to LunaSVG extended, -- which makes it able to render such Wikipedia SVGs correctly. -- We need to keep the style= attribute, which usually specifies width and height -- in 'ex' units, and a vertical-align we want to keep to align baselines. local keep_style if src:find("/math/render/svg/") then -- src = src:gsub("/math/render/svg/", "/math/render/png/") -- no longer needed keep_style = true end local cur_image if seen_images[src] then -- already seen cur_image = seen_images[src] else local src_ext = src if src_ext:find("?") then -- "/w/extensions/wikihiero/img/hiero_D22.png?0b8f1" src_ext = src_ext:match("(.-)%?") -- remove ?blah end local ext = src_ext:match(".*%.(%S%S%S?%S?%S?)$") -- extensions are only 2 to 5 chars if ext == nil or ext == "" then if src_ext:find("/math/render/svg/") then ext = "svg" elseif src_ext:find("/math/render/png/") then ext = "png" else -- we won't know what mimetype to use, ignore it logger.info("no file extension found in ", src) return nil end end ext = ext:lower() local imgid = string.format("img%05d", imagenum) local imgpath = string.format("images/%s.%s", imgid, ext) local mimetype = ext_to_mimetype[ext] or "" local width = tonumber(img_tag:match([[width="([^"]*)"]])) local height = tonumber(img_tag:match([[height="([^"]*)"]])) -- Get higher resolution (2x) image url local src2x = nil local srcset = img_tag:match([[srcset="([^"]*)"]]) if srcset then srcset = " "..srcset.. ", " -- for next pattern to possibly match 1st or last item src2x = srcset:match([[ (%S+) 2x, ]]) if src2x then if src2x:sub(1,2) == "//" then src2x = "https:" .. src2x elseif src2x:sub(1,1) == "/" then -- non absolute url src2x = wiki_base_url .. src2x end end end cur_image = { imgid = imgid, imgpath = imgpath, src = src, src2x = src2x, mimetype = mimetype, width = width, height = height, } table.insert(images, cur_image) seen_images[src] = cur_image -- Use first image of reasonable size (not an icon) and portrait-like as cover-image if not cover_imgid and width and width > 50 and height and height > 50 and height > width then cover_imgid = imgid end imagenum = imagenum + 1 end -- crengine will NOT use width and height attributes, but it will use -- those found in a style attribute. -- If we get src2x images, crengine will scale them down to the 1x image size -- (less space wasted by images while reading), but the 2x quality will be -- there when image is viewed full screen with ImageViewer widget. local style_props = {} if cur_image.width then table.insert(style_props, string.format("width: %spx", cur_image.width)) end if cur_image.height then table.insert(style_props, string.format("height: %spx", cur_image.height)) end local style = table.concat(style_props, "; ") if keep_style then -- for /math/render/svg/ style = img_tag:match([[style="([^"]*)"]]) end return string.format([[]], cur_image.imgpath, style) end html = html:gsub("(<%s*img [^>]*>)", processImg) logger.dbg("Images found in html:", images) -- See what to do with images local include_images = false local use_img_2x = false if with_images then -- If no UI (Trapper:wrap() not called), UI:confirm() will answer true if #images > 0 then include_images = UI:confirm(T(_("This article contains %1 images.\nWould you like to download and include them in the generated EPUB file?"), #images), _("Don't include"), _("Include")) if include_images then use_img_2x = UI:confirm(_("Would you like to use slightly higher quality images? This will result in a bigger file size."), _("Standard quality"), _("Higher quality")) end else UI:info(_("This article does not contain any images.")) ffiutil.sleep(1) -- Let the user see that end end if not include_images then -- Remove img tags to avoid little blank squares of missing images html = html:gsub("<%s*img [^>]*>", "") -- We could remove the whole image container
    , -- but it's a lot of nested
    and not easy to do. -- So the user will see the image legends and know a bit about -- the images he chose to not get. end UI:info(_("Building EPUB…")) -- Open the zip file (with .tmp for now, as crengine may still -- have a handle to the final epub_path, and we don't want to -- delete a good one if we fail/cancel later) local epub_path_tmp = epub_path .. ".tmp" local ZipWriter = require("ffi/zipwriter") local epub = ZipWriter:new{} if not epub:open(epub_path_tmp) then return false end -- We now create and add all the required epub files -- ---------------------------------------------------------------- -- /mimetype : always "application/epub+zip" epub:add("mimetype", "application/epub+zip") -- ---------------------------------------------------------------- -- /META-INF/container.xml : always the same content epub:add("META-INF/container.xml", [[ ]]) -- ---------------------------------------------------------------- -- OEBPS/content.opf : metadata + list of other files (paths relative to OEBPS/ directory) -- Other possible items in this file that are of no interest to crengine : -- In : -- -- -- (crengine only uses to get the cover image) -- In : -- -- And a section : -- -- -- -- local koreader_version = "KOReader" if lfs.attributes("git-rev", "mode") == "file" then local Version = require("version") koreader_version = "KOReader " .. Version:getCurrentRevision() end local content_opf_parts = {} -- head local meta_cover = "" if include_images and cover_imgid then meta_cover = string.format([[]], cover_imgid) end table.insert(content_opf_parts, string.format([[ %s Wikipedia %s %s %s %s %s ]], page_cleaned, lang:upper(), bookid, lang, koreader_version, meta_cover)) -- images files if include_images then for inum, img in ipairs(images) do table.insert(content_opf_parts, string.format([[ %s]], img.imgid, img.imgpath, img.mimetype, "\n")) end end -- tail table.insert(content_opf_parts, [[ ]]) epub:add("OEBPS/content.opf", table.concat(content_opf_parts)) -- ---------------------------------------------------------------- -- OEBPS/stylesheet.css -- crengine will use its own data/epub.css, we just add/fix a few styles -- to look more alike wikipedia web pages (that the user can ignore -- with "Embedded Style" off) epub:add("OEBPS/stylesheet.css", [[ /* Make section headers looks left aligned and avoid some page breaks */ h1, h2 { page-break-before: always; page-break-inside: avoid; page-break-after: avoid; text-align: start; } h3, h4, h5, h6 { page-break-before: auto; page-break-inside: avoid; page-break-after: avoid; text-align: start; } /* Styles for our centered titles on first page */ h1.koreaderwikifrontpage, h5.koreaderwikifrontpage { page-break-before: avoid; text-align: center; margin-top: 0; } p.koreaderwikifrontpage { font-style: italic; font-size: 90%; text-indent: 0; margin: 1em 2em 1em 2em; } hr.koreaderwikifrontpage { margin-left: 20%; margin-right: 20%; margin-bottom: 1.2em; } /* So many links, make them look like normal text except for underline */ a { display: inline; text-decoration: underline; color: inherit; font-weight: inherit; } /* No underline for links without their href that we removed */ a.newwikinonexistent { text-decoration: none; } /* Don't waste left margin for TOC, notes and other lists */ ul, ol { margin-left: 0; } ul:dir(rtl), ol:dir(rtl) { margin-right: 0; } /* OL in Wikipedia pages may inherit their style-type from a wrapping div, * ensure they fallback to decimal with inheritance */ body { list-style-type: decimal; } ol.references { list-style-type: inherit; /* Allow hiding these pages as their content is available as footnotes */ -cr-hint: non-linear; } /* Show a box around image thumbnails */ div.thumb { border: dotted 1px black; margin: 0.5em 2.5em 0.5em 2.5em; padding: 0.5em 0.5em 0.2em 0.5em; padding-top: ]].. (include_images and "0.5em" or "0.15em") .. [[; text-align: center; font-size: 90%; page-break-inside: avoid; } /* Allow main thumbnails to float */ body > div > div.thumb { float: right !important; /* Change some of their styles when floating */ -cr-only-if: float-floatboxes; clear: right; margin: 0 0 0.2em 0.5em !important; font-size: 80% !important; /* Ensure a fixed width when not in "web" render mode */ -cr-only-if: float-floatboxes -allow-style-w-h-absolute-units; width: 33% !important; } body > div:dir(rtl) > div.thumb { /* invert if RTL */ float: left !important; -cr-only-if: float-floatboxes; clear: left; margin: 0 0.5em 0.2em 0 !important; } /* Allow original mix of left/right floats in web mode */ body > div > div.thumb.tleft { -cr-only-if: float-floatboxes allow-style-w-h-absolute-units; float: left !important; clear: left; margin: 0 0.5em 0.2em 0 !important; } body > div > div.thumb.tright { -cr-only-if: float-floatboxes allow-style-w-h-absolute-units; float: right !important; clear: right; margin: 0 0 0.2em 0.5em !important; } body > div > div.thumb img { /* Make float's inner images 100% of their container's width when not in "web" mode */ -cr-only-if: float-floatboxes -allow-style-w-h-absolute-units; width: 100% !important; height: 100% !important; } /* Some other (usually wide) thumbnails are wrapped in a DIV.center: * avoid having them overflowing in web mode (no issue in other modes). * (Use "width: auto", as crengine does not support "max-width:") */ body > div > div.center > div.thumb * { -cr-only-if: allow-style-w-h-absolute-units; width: auto !important; } /* Style gallery and the galleryboxes it contains. /* LI.galleryboxes about the same topic may be in multiple UL.gallery * containers, and Wikipedia may group them by 3 or 4 in each container. * We'd rather want them in a single group, so they can be laid out * taking the full width depending on render mode and screen dpi. * So, make UL.gallery inline, and all its children inline-block. * The consecutive inline UL.gallery will be wrapped by crengine * in a single autoBoxing element, that we style a bit, hoping * Wikipedia properly have all its 1st level elements "display:block" * and we do not style other autoBoxed inlines at this level. */ body > div > ul.gallery, body > div > autoBoxing > ul.gallery { display: inline; /* keep them inline once autoBoxed */ } body > div > autoBoxing { /* created by previous style */ width: 100%; margin-top: 1em; margin-bottom: 1em; clear: both; /* Have non-full-width inline-blocks laid out centered */ text-align: center; } body > div > ul.gallery > *, body > div > autoBoxing > ul.gallery > * { /* Make all ul.gallery children inline-block and taking 100% width * so they feel like classically stacked display:block */ display: inline-block; width: 100%; /* Have gallerycaption and galleryboxes content centered */ text-align: center; } .gallerycaption { font-weight: bold; page-break-inside: avoid; page-break-after: avoid; } li.gallerybox { /* Style gallerybox just as main thumbs */ list-style-type: none; border: dotted 1px black; margin: 0.5em 2.5em 0.5em 2.5em !important; padding: 0.5em 0.5em 0.2em 0.5em !important; padding-top: ]].. (include_images and "0.5em" or "0.15em") .. [[ !important; text-indent: 0; font-size: 90%; vertical-align: top; /* align them all to their top */ /* No float here, but use these to distinguish flat/book/web modes */ -cr-only-if: -float-floatboxes; width: 100% !important; /* flat mode: force full width */ -cr-only-if: float-floatboxes; /* Remove our wide horizontal margins in book/web modes */ margin: 0.5em 0.5em 0.5em 0.5em !important; -cr-only-if: float-floatboxes -allow-style-w-h-absolute-units; /* Set a fixed width when not in "web" mode */ width: 25% !important; /* will allow rows of 3 */ /* In web mode, allow the specified widths in HTML style attributes */ } li.gallerybox p { /* Reset indent as we have everything centered */ text-indent: 0; } li.gallerybox div.thumb { /* Remove thumb styling, which we have set on the gallerybox */ border: solid 1px white; margin: 0; padding: 0; } li.gallerybox div.thumb div { /* Override this one often set in style="" with various values */ margin: 0 !important; } li.gallerybox * { /* Have sub elements take the full container width when not in "web" mode */ -cr-only-if: float-floatboxes -allow-style-w-h-absolute-units; width: 100% !important; } li.gallerybox div.thumb img { /* Make inline-block's inner images 100% of their container's width * when not in "web" mode (same as previous, but with height */ -cr-only-if: float-floatboxes -allow-style-w-h-absolute-units; width: 100% !important; height: 100% !important; } table { margin-top: 1em; margin-bottom: 1em; /* Wikipedia tables are often set as float, make them full width When not floating */ -cr-only-if: -float-floatboxes; width: 100% !important; } .citation { font-style: italic; } /* hide some view/edit/discuss short links displayed as "v m d" */ .nv-view, .nv-edit, .nv-talk { display: none; } /* hiding .noprint may discard some interesting links */ ]]) -- ---------------------------------------------------------------- -- OEBPS/toc.ncx : table of content local toc_ncx_parts = {} local depth = 0 local cur_level = 0 local np_end = [[]] local num = 1 -- Add our own first section for first page, with page name as title table.insert(toc_ncx_parts, string.format([[%s]], num, num, page_cleaned)) table.insert(toc_ncx_parts, np_end) -- Wikipedia sections items seem to be already sorted by index, so no need to sort for isec, s in ipairs(sections) do num = num + 1 -- Some chars in headings are converted to html entities in the -- wikipedia-generated HTML. We need to do the same in TOC links -- for the links to be valid. local s_anchor = s.anchor:gsub("&", "&"):gsub('"', """):gsub(">", ">"):gsub("<", "<") local s_title = string.format("%s %s", s.number, s.line) -- Titles may include and other html tags: let's remove them as -- our TOC can only display text s_title = (s_title:gsub("(%b<>)", "")) -- We need to do as for page_htmltitle above. But headings can contain -- html entities for < and > that we need to put back as html entities s_title = util.htmlEntitiesToUtf8(s_title):gsub("&", "&"):gsub(">", ">"):gsub("<", "<") local s_level = s.toclevel if s_level > depth then depth = s_level -- max depth required in toc.ncx end if s_level == cur_level then table.insert(toc_ncx_parts, np_end) -- close same-level previous navPoint elseif s_level < cur_level then table.insert(toc_ncx_parts, np_end) -- close same-level previous navPoint while s_level < cur_level do -- close all in-between navPoint table.insert(toc_ncx_parts, np_end) cur_level = cur_level - 1 end elseif s_level > cur_level + 1 then -- a jump from level N to level N+2 or more ... should not happen -- per epub spec, but we don't know about wikipedia... -- so we create missing intermediate navPoints with same anchor as current section while s_level > cur_level + 1 do table.insert(toc_ncx_parts, "\n"..(" "):rep(cur_level)) table.insert(toc_ncx_parts, string.format([[-]], num, num, s_anchor)) cur_level = cur_level + 1 num = num + 1 end -- elseif s_level == cur_level + 1 then -- sublevel, nothing to close, nothing to add end cur_level = s_level table.insert(toc_ncx_parts, "\n"..(" "):rep(cur_level)) -- indentation, in case a person looks at it table.insert(toc_ncx_parts, string.format([[%s]], num, num, s_title, s_anchor)) end -- close nested while cur_level > 0 do table.insert(toc_ncx_parts, np_end) cur_level = cur_level - 1 end -- Prepend NCX head table.insert(toc_ncx_parts, 1, string.format([[ %s ]], bookid, depth, page_cleaned)) -- Append NCX tail table.insert(toc_ncx_parts, [[ ]]) epub:add("OEBPS/toc.ncx", table.concat(toc_ncx_parts)) -- ---------------------------------------------------------------- -- OEBPS/content.html -- Some small fixes to Wikipedia HTML to make crengine and the user happier -- Most images are in a link to the image info page, which is a useless -- external link for us, so let's remove this link. html = html:gsub("]*>%s*(<%s*img [^>]*>)%s*", "%1") -- crengine does not support the family of tags for displaying formulas, -- which results in lots of space taken by individual character in the formula, -- each on a single line... -- Also, usally, these tags are followed by a tag pointing to a -- SVG version of the formula, that we took care earlier to change the url to -- point to a PNG version of the formula (which is still not perfect, as it does -- not adjust to the current html font size, but it is at least readable). -- So, remove the whole ... content html = html:gsub([[]], "") -- Fix internal wikipedia links with full server url (including lang) so -- ReaderLink can notice them and deal with them with a LookupWikipedia event. -- We need to remove any "?somekey=somevalue" from url (a real "?" part of the -- wiki_page word would be encoded as %3F, but ReaderLink would get it decoded and -- would not be able to distinguish them). -- Do that first (need to be done first) for full links to other language wikipedias local cleanOtherLangWikiPageTitle = function(wiki_lang, wiki_page) wiki_page = wiki_page:gsub("%?.*", "") return string.format([[href="https://%s.wikipedia.org/wiki/%s"]], wiki_lang, wiki_page) end html = html:gsub([[href="https?://([^%.]+).wikipedia.org/wiki/([^"]*)"]], cleanOtherLangWikiPageTitle) -- Now, do it for same wikipedia short urls local cleanWikiPageTitle = function(wiki_page) wiki_page = wiki_page:gsub("%?.*", "") return string.format([[href="%s/wiki/%s"]], wiki_base_url, wiki_page) end html = html:gsub([[href="/wiki/([^"]*)"]], cleanWikiPageTitle) -- Remove href from links to non existant wiki page so they are not clickable : -- PageTitle____on -- (removal of the href="" will make them non clickable) html = html:gsub([[]* class="new"[^>]*>]], [[]]) -- Fix some other protocol-less links to wikipedia (href="//fr.wikipedia.org/w/index.php..) html = html:gsub([[href="//]], [[href="https://]]) if self.wiki_prettify then -- Prepend some symbols to section titles for a better visual feeling of hierarchy html = html:gsub("

    ", "

    "..h1_sym.." ") html = html:gsub("

    ", "

    "..h2_sym.." ") html = html:gsub("

    ", "

    "..h3_sym.." ") html = html:gsub("

    ", "

    "..h4_sym.." ") html = html:gsub("

    ", "
    "..h5_sym.." ") html = html:gsub("
    ", "
    "..h6_sym.." ") end -- Note: in all the gsub patterns above, we used lowercase for tags and attributes -- because it's how they are in wikipedia HTML and it makes the pattern simple. -- If one day this changes, they'll have to be replaced with href => [Hh][Rr][Ee][Ff] ... -- We can finally build the final HTML with some header of our own local saved_on = T(_("Saved on %1"), os.date("%b %d, %Y %H:%M:%S")) local online_version_htmllink = string.format([[%s]], wiki_base_url, page:gsub(" ", "_"), _("online version")) local see_online_version = T(_("See %1 for up-to-date content"), online_version_htmllink) -- Set dir= attribute on the HTML tag for RTL languages local html_dir = "" if self:isWikipediaLanguageRTL(lang) then html_dir = ' dir="rtl"' end epub:add("OEBPS/content.html", string.format([[ %s

    %s

    Wikipedia %s

    %s
    %s


    %s ]], html_dir, page_cleaned, page_htmltitle, lang:upper(), saved_on, see_online_version, html)) -- Force a GC to free the memory we used till now (the second call may -- help reclaim more memory). collectgarbage() collectgarbage() -- ---------------------------------------------------------------- -- OEBPS/images/* if include_images then local nb_images = #images for inum, img in ipairs(images) do -- Process can be interrupted at this point between each image download -- by tapping while the InfoMessage is displayed -- We use the fast_refresh option from image #2 for a quicker download local go_on = UI:info(T(_("Retrieving image %1 / %2 …"), inum, nb_images), inum >= 2) if not go_on then cancelled = true break end local src = img.src if use_img_2x and img.src2x then src = img.src2x end logger.dbg("Getting img ", src) local success, content = getUrlContent(src) -- success, content = getUrlContent(src..".unexistant") -- to simulate failure if success then logger.dbg("success, size:", #content) else logger.info("failed fetching:", src) end if success then -- Images do not need to be compressed, so spare some cpu cycles local no_compression = true if img.mimetype == "image/svg+xml" then -- except for SVG images (which are XML text) no_compression = false end epub:add("OEBPS/"..img.imgpath, content, no_compression) else go_on = UI:confirm(T(_("Downloading image %1 failed. Continue anyway?"), inum), _("Stop"), _("Continue")) if not go_on then cancelled = true break end end end end -- Done with adding files if cancelled then if UI:confirm(_("Download did not complete.\nDo you want to create an EPUB with the already downloaded images?"), _("Don't create"), _("Create")) then cancelled = false end end if cancelled then UI:info(_("Canceled. Cleaning up…")) else UI:info(_("Packing EPUB…")) end epub:close() -- This was nearly a no-op, so sleep a bit to make that progress step seen ffiutil.usleep(300000) UI:reset() -- close last InfoMessage if cancelled then -- Build was cancelled, remove half created .epub if lfs.attributes(epub_path_tmp, "mode") == "file" then os.remove(epub_path_tmp) end return false end -- Finally move the .tmp to the final file os.rename(epub_path_tmp, epub_path) logger.info("successfully created:", epub_path) -- Force a GC to free the memory we used (the second call may help -- reclaim more memory). collectgarbage() collectgarbage() return true end -- Wrap Wikipedia:createEpub() with UI progress info, provided -- by Trapper module. function Wikipedia:createEpubWithUI(epub_path, page, lang, result_callback) -- To do any UI interaction while building the EPUB, we need -- to use a coroutine, so that our code can be suspended while waiting -- for user interaction, and resumed by UI widgets callbacks. -- All this is hidden and done by Trapper with a simple API. local Trapper = require("ui/trapper") Trapper:wrap(function() Trapper:setPausedText("Download paused") -- If errors in Wikipedia:createEpub(), the coroutine (used by -- Trapper) would just abort (no reader crash, no error logged). -- So we use pcall to catch any errors, log it, and report -- the failure via result_callback. local ok, success = pcall(self.createEpub, self, epub_path, page, lang, true) if ok and success then result_callback(true) else Trapper:reset() -- close any last widget not cleaned if error logger.warn("Wikipedia.createEpub pcall:", ok, success) result_callback(false) end end) end return Wikipedia