Class: Softcover::Builders::Epub
- Inherits:
-
Softcover::Builder
- Object
- Softcover::Builder
- Softcover::Builders::Epub
- Defined in:
- lib/softcover/builders/epub.rb
Constant Summary
Constants included from Utils
Instance Attribute Summary
Attributes inherited from Softcover::Builder
Instance Method Summary collapse
- #build!(options = {}) ⇒ Object
- #chapter_name(n) ⇒ Object
-
#chapter_template(title, content) ⇒ Object
Returns the HTML template for a chapter.
-
#chapters ⇒ Object
Returns the chapters to write.
-
#clean_book_id(filename) ⇒ Object
Removes the ‘#book’ CSS id.
- #container_xml ⇒ Object
-
#content_opf ⇒ Object
Returns the content configuration file.
-
#copy_image_files ⇒ Object
Copies the image files from the HTML version of the document.
- #cover_id ⇒ Object
- #cover_page ⇒ Object
- #create_directories ⇒ Object
- #create_style_files(options) ⇒ Object
-
#html_with_math(chapter, images_dir, texmath_dir, pngs, options = {}) ⇒ Object
Returns HTML for HTML source that includes math.
- #ibooks_xml ⇒ Object
-
#inkscape ⇒ Object
Returns the Inkscape executable (if available).
-
#make_epub(options = {}) ⇒ Object
Make the EPUB, which is basically just a zipped HTML file.
-
#math?(string) ⇒ Boolean
Returns true if a string appears to have LaTeX math.
-
#move_epub ⇒ Object
Move the completed EPUB book to the ‘ebooks` directory.
-
#nav_html ⇒ Object
Returns the nav HTML content.
-
#nav_link(chapter) ⇒ Object
Returns a navigation link for the chapter.
-
#phantomjs ⇒ Object
Returns the PhantomJS executable (if available).
-
#preview? ⇒ Boolean
Returns true if generating a book preview.
-
#remove_html ⇒ Object
Removes HTML.
-
#remove_images ⇒ Object
Removes images in case they are stale.
-
#strip_attributes(doc) ⇒ Object
Strip attributes that are invalid in EPUB documents.
-
#toc_ncx ⇒ Object
Returns the Table of Contents for the spine.
-
#write_container_xml ⇒ Object
Writes the container XML file.
-
#write_contents ⇒ Object
Writes the content.opf file.
-
#write_html(options = {}) ⇒ Object
Writes the HTML for the EPUB.
-
#write_ibooks_xml ⇒ Object
Writes iBooks-specific XML.
-
#write_mimetype ⇒ Object
Writes the mimetype file.
-
#write_nav ⇒ Object
Writes the navigation file.
-
#write_toc ⇒ Object
Writes the Table of Contents.
- #zip ⇒ Object
Methods included from EpubUtils
#content_opf_template, #cover?, #cover_img, #cover_img_path, #escape, #images_dir, #nav_html_template, #toc_ncx_template
Methods included from Output
should_output?, silence!, silent?, #system, unsilence!
Methods inherited from Softcover::Builder
Methods included from Utils
#add_highlight_class!, #article?, #as_size, #book_file_lines, #chapter_label, #commands, #current_book, #dependency_filename, #digest, #executable, #execute, #filename_or_default, #get_filename, #in_book_directory?, #language_labels, #linux?, #logged_in?, #master_content, #master_filename, #master_latex_header, #mkdir, #non_comment_lines, #os_x?, #path, #raw_lines, #reset_current_book!, #rm, #rm_r, #silence, #source, #template_dir, #tmpify, #unpublish_slug, #write_master_latex_file, #write_pygments_file
Constructor Details
This class inherits a constructor from Softcover::Builder
Instance Method Details
#build!(options = {}) ⇒ Object
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# File 'lib/softcover/builders/epub.rb', line 127 def build!(={}) @preview = [:preview] Softcover::Builders::Html.new.build! if manifest.markdown? opts = .merge({ source: :polytex, origin: :markdown }) self.manifest = Softcover::BookManifest.new(opts) end remove_html remove_images create_directories write_mimetype write_container_xml write_ibooks_xml write_toc write_nav copy_image_files write_html() write_contents create_style_files() make_epub() move_epub end |
#chapter_name(n) ⇒ Object
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# File 'lib/softcover/builders/epub.rb', line 525 def chapter_name(n) n == 0 ? language_labels["frontmatter"] : chapter_label(n) end |
#chapter_template(title, content) ⇒ Object
Returns the HTML template for a chapter.
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# File 'lib/softcover/builders/epub.rb', line 544 def chapter_template(title, content) %(<?xml version="1.0" encoding="utf-8"?> <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>#{title}</title> <link rel="stylesheet" href="styles/pygments.css" type="text/css" /> <link rel="stylesheet" href="styles/softcover.css" type="text/css" /> <link rel="stylesheet" href="styles/epub.css" type="text/css" /> <link rel="stylesheet" href="styles/custom.css" type="text/css"/> <link rel="stylesheet" href="styles/custom_epub.css" type="text/css"/> <link rel="stylesheet" type="application/vnd.adobe-page-template+xml" href="styles/page-template.xpgt" /> </head> <body> #{content} </body> </html>) end |
#chapters ⇒ Object
Returns the chapters to write.
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# File 'lib/softcover/builders/epub.rb', line 202 def chapters preview? ? manifest.preview_chapters : manifest.chapters end |
#clean_book_id(filename) ⇒ Object
Removes the ‘#book’ CSS id. For some reason, EPUB books hate the #book ids in the stylesheet (i.e., such books fail to validate), so remove them.
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# File 'lib/softcover/builders/epub.rb', line 378 def clean_book_id(filename) File.read(filename).gsub(/#book/, '') end |
#container_xml ⇒ Object
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# File 'lib/softcover/builders/epub.rb', line 448 def container_xml %(<?xml version="1.0"?> <container version="1.0" xmlns="urn:oasis:names:tc:opendocument:xmlns:container"> <rootfiles> <rootfile full-path="OEBPS/content.opf" media-type="application/oebps-package+xml"/> </rootfiles> </container>) end |
#content_opf ⇒ Object
Returns the content configuration file.
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# File 'lib/softcover/builders/epub.rb', line 467 def content_opf man_ch = chapters.map do |chapter| %(<item id="#{chapter.slug}" href="#{chapter.fragment_name}" media-type="application/xhtml+xml"/>) end toc_ch = chapters.map do |chapter| %(<itemref idref="#{chapter.slug}"/>) end image_files = Dir['epub/OEBPS/images/**/*'].select { |f| File.file?(f) } images = image_files.map do |image| ext = File.extname(image).sub('.', '') # e.g., 'png' ext = 'jpeg' if ext == 'jpg' # Strip off the leading 'epub/OEBPS'. sep = File::SEPARATOR href = image.split(sep)[2..-1].join(sep) # Define an id based on the filename. # Prefix with 'img-' in case the filname starts with an # invalid character such as a number. label = File.basename(image).gsub('.', '-') id = "img-#{label}" %(<item id="#{id}" href="#{href}" media-type="image/#{ext}"/>) end content_opf_template(manifest.title, manifest.copyright, manifest., manifest.uuid, cover_id, toc_ch, man_ch, images) end |
#copy_image_files ⇒ Object
Copies the image files from the HTML version of the document.
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# File 'lib/softcover/builders/epub.rb', line 383 def copy_image_files # Copy over all images to guarantee the same directory structure. FileUtils.cp_r(File.join('html', 'images'), File.join('epub', 'OEBPS')) # Parse the full HTML file with Nokogiri to get images actually used. html = File.read(manifest.full_html_file) html_image_filenames = Nokogiri::HTML(html).css('img').map do |node| node.attributes['src'].value end # Form the corresponding EPUB image paths. used_image_filenames = html_image_filenames.map do |filename| "epub/OEBPS/#{filename}" end.to_set # Delete unused images. Dir.glob("epub/OEBPS/images/**/*").each do |image| next if File.directory?(image) rm image unless used_image_filenames.include?(image) end end |
#cover_id ⇒ Object
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# File 'lib/softcover/builders/epub.rb', line 509 def cover_id cover? ? "img-#{cover_img.sub('.', '-')}" : nil end |
#cover_page ⇒ Object
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# File 'lib/softcover/builders/epub.rb', line 493 def cover_page %(<?xml version="1.0" encoding="utf-8"?> <!DOCTYPE html> <html xmlns="http://www.w3.org/1999/xhtml"> <head> <title>Cover</title> </head> <body> <div id="cover"> <img width="573" height="800" src="images/#{cover_img}" alt="cover" /> </div> </body> </html> ) end |
#create_directories ⇒ Object
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# File 'lib/softcover/builders/epub.rb', line 166 def create_directories mkdir('epub') mkdir(path('epub/OEBPS')) mkdir(path('epub/OEBPS/styles')) mkdir(path('epub/META-INF')) mkdir(images_dir) mkdir('ebooks') end |
#create_style_files(options) ⇒ Object
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# File 'lib/softcover/builders/epub.rb', line 357 def create_style_files() html_styles = File.join('html', 'stylesheets') epub_styles = File.join('epub', 'OEBPS', 'styles') FileUtils.cp(File.join(html_styles, 'pygments.css'), epub_styles) File.write(File.join(epub_styles, 'softcover.css'), clean_book_id(path("#{html_styles}/softcover.css"))) # Copy over the EPUB-specific CSS. template_dir = Softcover::Utils.template_dir() epub_css = File.join(template_dir, epub_styles, 'epub.css') FileUtils.cp(epub_css, epub_styles) # Copy over custom CSS. File.write(File.join(epub_styles, 'custom.css'), clean_book_id(path("#{html_styles}/custom.css"))) end |
#html_with_math(chapter, images_dir, texmath_dir, pngs, options = {}) ⇒ Object
Returns HTML for HTML source that includes math. As a side-effect, html_with_math creates PNGs corresponding to any math in the given source. The technique involves using PhantomJS to hit the HTML source for each page containing math to create SVGs for every math element. Since ereader support for SVGs is spotty, they are then converted to PNGs using Inkscape. The filenames are SHAs of their contents, which arranges both for unique filenames and for automatic disk caching.
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# File 'lib/softcover/builders/epub.rb', line 260 def html_with_math(chapter, images_dir, texmath_dir, pngs, ={}) content = File.read(File.join("html", "#{chapter.slug}.html")) pagejs = "#{File.dirname(__FILE__)}/utils/page.js" url = "file://#{Dir.pwd}/html/#{chapter.slug}.html" cmd = "#{phantomjs} #{pagejs} #{url}" silence { silence_stream(STDERR) { system cmd } } # Sometimes in tests the phantomjs_source.html file is missing. # It shouldn't ever happen, but it does no harm to skip it. return nil unless File.exist?('phantomjs_source.html') raw_source = File.read('phantomjs_source.html') source = strip_attributes(Nokogiri::HTML(raw_source)) rm 'phantomjs_source.html' # Remove the first body div, which is the hidden MathJax SVGs. if (mathjax_svgs = source.at_css('body div')) mathjax_svgs.remove else # There's not actually any math, so return nil. return nil end # Remove all the unneeded raw TeX displays. source.css('script').each(&:remove) # Remove all the MathJax preview spans. source.css('MathJax_Preview').each(&:remove) # Suck out all the SVGs svgs = source.css('div#book svg') frames = source.css('span.MathJax_SVG') svgs.zip(frames).each do |svg, frame| # Save the SVG file. svg['viewBox'] = svg['viewbox'] svg.remove_attribute('viewbox') first_child = frame.children.first first_child.replace(svg) unless svg == first_child output = svg.to_xhtml svg_filename = File.join(texmath_dir, "#{digest(output)}.svg") File.write(svg_filename, output) # Convert to PNG. png_filename = svg_filename.sub('.svg', '.png') pngs << png_filename unless File.exist?(png_filename) unless [:silent] || [:quiet] puts "Creating #{png_filename}" end svg_height = svg['style'].scan(/height: (.*?);/).flatten.first scale_factor = 8 # This scale factor turns out to look good. h = scale_factor * svg_height.to_f cmd = "#{inkscape} -f #{svg_filename} -e #{png_filename} -h #{h}pt" if [:silent] silence { silence_stream(STDERR) { system cmd } } else silence_stream(STDERR) { system cmd } end end rm svg_filename png = Nokogiri::XML::Node.new('img', source) png['src'] = File.join('images', 'texmath', File.basename(png_filename)) png['alt'] = png_filename.sub('.png', '') svg.replace(png) end # Make references relative. source.css('a.hyperref').each do |ref_node| ref_node['href'] = ref_node['href'].sub('.html', '_fragment.html') end source.at_css('div#book').children.to_xhtml end |
#ibooks_xml ⇒ Object
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# File 'lib/softcover/builders/epub.rb', line 457 def ibooks_xml %(<?xml version="1.0" encoding="UTF-8"?> <display_options> <platform name="*"> <option name="specified-fonts">true</option> </platform> </display_options>) end |
#inkscape ⇒ Object
Returns the Inkscape executable (if available).
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# File 'lib/softcover/builders/epub.rb', line 333 def inkscape @inkscape ||= executable(dependency_filename(:inkscape)) end |
#make_epub(options = {}) ⇒ Object
Make the EPUB, which is basically just a zipped HTML file.
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# File 'lib/softcover/builders/epub.rb', line 404 def make_epub(={}) filename = manifest.filename zfname = filename + '.zip' base_file = "#{zip} -X0 #{zfname} mimetype" fullzip = "#{zip} -rDXg9" = "#{fullzip} #{zfname} META-INF -x \*.DS_Store -x mimetype" main_info = "#{fullzip} #{zfname} OEBPS -x \*.DS_Store \*.gitkeep" rename = "mv #{zfname} #{filename}.epub" commands = [base_file, , main_info, rename] command = commands.join(' && ') Dir.chdir('epub') do if Softcover.test? || [:quiet] || [:silent] silence { system(command) } else system(command) end end end |
#math?(string) ⇒ Boolean
Returns true if a string appears to have LaTeX math. We detect math via opening math commands: (, [, and beginequation This gives a false positive when math is included in verbatim environments and nowhere else, but it does little harm (requiring only an unnecessary call to page.js).
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# File 'lib/softcover/builders/epub.rb', line 353 def math?(string) !!string.match(/(?:\\\(|\\\[|\\begin{equation})/) end |
#move_epub ⇒ Object
Move the completed EPUB book to the ‘ebooks` directory. Note that we handle the case of a preview book as well.
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# File 'lib/softcover/builders/epub.rb', line 429 def move_epub origin = manifest.filename target = preview? ? origin + '-preview' : origin FileUtils.mv(File.join('epub', "#{origin}.epub"), File.join('ebooks', "#{target}.epub")) end |
#nav_html ⇒ Object
Returns the nav HTML content.
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# File 'lib/softcover/builders/epub.rb', line 530 def nav_html nav_list = manifest.chapters.map do |chapter| element = preview? ? chapter.title : nav_link(chapter) %(<li>#{element}</li>) end nav_html_template(manifest.title, nav_list) end |
#nav_link(chapter) ⇒ Object
Returns a navigation link for the chapter.
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# File 'lib/softcover/builders/epub.rb', line 539 def nav_link(chapter) %(<a href="#{chapter.fragment_name}">#{chapter.html_title}</a>) end |
#phantomjs ⇒ Object
Returns the PhantomJS executable (if available).
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# File 'lib/softcover/builders/epub.rb', line 328 def phantomjs @phantomjs ||= executable(dependency_filename(:phantomjs)) end |
#preview? ⇒ Boolean
Returns true if generating a book preview.
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# File 'lib/softcover/builders/epub.rb', line 151 def preview? !!@preview end |
#remove_html ⇒ Object
Removes HTML. All the HTML is generated, so this clears out any unused files.
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# File 'lib/softcover/builders/epub.rb', line 157 def remove_html FileUtils.rm(Dir.glob(path('epub/OEBPS/*.html'))) end |
#remove_images ⇒ Object
Removes images in case they are stale.
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# File 'lib/softcover/builders/epub.rb', line 162 def remove_images rm_r images_dir end |
#strip_attributes(doc) ⇒ Object
Strip attributes that are invalid in EPUB documents.
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# File 'lib/softcover/builders/epub.rb', line 338 def strip_attributes(doc) attrs = %w[data-tralics-id data-label data-number data-chapter role aria-readonly target] doc.tap do attrs.each do |attr| doc.xpath("//@#{attr}").remove end end end |
#toc_ncx ⇒ Object
Returns the Table of Contents for the spine.
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# File 'lib/softcover/builders/epub.rb', line 514 def toc_ncx chapter_nav = [] chapters.each_with_index do |chapter, n| chapter_nav << %(<navPoint id="#{chapter.slug}" playOrder="#{n+1}">) chapter_nav << %( <navLabel><text>#{chapter_name(n)}</text></navLabel>) chapter_nav << %( <content src="#{chapter.fragment_name}"/>) chapter_nav << %(</navPoint>) end toc_ncx_template(manifest.title, manifest.uuid, chapter_nav) end |
#write_container_xml ⇒ Object
Writes the container XML file. This is required by the EPUB standard.
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# File 'lib/softcover/builders/epub.rb', line 183 def write_container_xml File.write(path('epub/META-INF/container.xml'), container_xml) end |
#write_contents ⇒ Object
Writes the content.opf file. This is required by the EPUB standard.
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# File 'lib/softcover/builders/epub.rb', line 197 def write_contents File.write(path('epub/OEBPS/content.opf'), content_opf) end |
#write_html(options = {}) ⇒ Object
Writes the HTML for the EPUB. Included is a math detector that processes the page with MathJax (via page.js) so that math can be included in EPUB (and thence MOBI).
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# File 'lib/softcover/builders/epub.rb', line 209 def write_html(={}) texmath_dir = File.join(images_dir, 'texmath') mkdir images_dir mkdir texmath_dir File.write(path('epub/OEBPS/cover.html'), cover_page) if cover? pngs = [] chapters.each_with_index do |chapter, i| target_filename = path("epub/OEBPS/#{chapter.fragment_name}") File.open(target_filename, 'w') do |f| content = File.read(path("html/#{chapter.fragment_name}")) doc = strip_attributes(Nokogiri::HTML(content)) body = doc.at_css('body') if body.nil? $stderr.puts "\nError: Document not built due to empty chapter" $stderr.puts "Chapters must include a title using the Markdown" $stderr.puts " # This is a chapter" $stderr.puts "or the LaTeX" $stderr.puts " \\chapter{This is a chapter}" exit(1) end inner_html = body.children.to_xhtml if math?(inner_html) html = html_with_math(chapter, images_dir, texmath_dir, pngs, ) html ||= inner_html # handle case of spurious math detection else html = inner_html end f.write(chapter_template("Chapter #{i}", html)) end end # Clean up unused PNGs. png_files = Dir[path("#{texmath_dir}/*.png")] (png_files - pngs).each do |f| if File.exist?(f) puts "Removing unused PNG #{f}" unless [:silent] FileUtils.rm(f) end end end |
#write_ibooks_xml ⇒ Object
Writes iBooks-specific XML. This allows proper display of monospace fonts in code samples, among other things.
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# File 'lib/softcover/builders/epub.rb', line 190 def write_ibooks_xml xml_filename = 'com.apple.ibooks.display-options.xml' File.write(path("epub/META-INF/#{xml_filename}"), ibooks_xml) end |
#write_mimetype ⇒ Object
Writes the mimetype file. This is required by the EPUB standard.
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# File 'lib/softcover/builders/epub.rb', line 177 def write_mimetype File.write(path('epub/mimetype'), 'application/epub+zip') end |
#write_nav ⇒ Object
Writes the navigation file. This is required by the EPUB standard.
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# File 'lib/softcover/builders/epub.rb', line 444 def write_nav File.write('epub/OEBPS/nav.html', nav_html) end |
#write_toc ⇒ Object
Writes the Table of Contents. This is required by the EPUB standard.
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# File 'lib/softcover/builders/epub.rb', line 438 def write_toc File.write('epub/OEBPS/toc.ncx', toc_ncx) end |
#zip ⇒ Object
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# File 'lib/softcover/builders/epub.rb', line 423 def zip @zip ||= executable(dependency_filename(:zip)) end |