Class: Epuber::Compiler::XHTMLProcessor

Inherits:
Object
  • Object
show all
Defined in:
lib/epuber/compiler/xhtml_processor.rb

Defined Under Namespace

Classes: UnparseableLinkError

Class Method Summary collapse

Class Method Details

.add_missing_root_elements(xhtml_doc, title, epub_version) ⇒ Object

Method to add all missing items in XML root

Required items:

- html (with all namespaces and other attributes)
- body
  - head (with title)

Parameters:

  • xhtml_doc (Nokogiri::XML::Document) —

    input XML document to work with

  • title (String) —

    title of this document, since this is required by EPUB specification

  • epub_version (Epuber::Version) —

    version of result EPUB

Returns:

  • nil



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# File 'lib/epuber/compiler/xhtml_processor.rb', line 83

def self.add_missing_root_elements(xhtml_doc, title, epub_version)
  # add missing body element
  if xhtml_doc.at_css('body').nil?
    xhtml_doc.root.surround_with_element('body')
  end

  # add missing root html element
  if xhtml_doc.at_css('html').nil?
    attrs               = {}
    attrs['xmlns']      = 'http://www.w3.org/1999/xhtml'
    attrs['xmlns:epub'] = 'http://www.idpf.org/2007/ops' if epub_version >= 3
    xhtml_doc.root.surround_with_element('html', attrs)
  end

  # add missing head in html
  if xhtml_doc.at_css('html > head').nil?
    html = xhtml_doc.css('html').first
    head = xhtml_doc.create_element('head')
    head << xhtml_doc.create_element('title', title)
    head << xhtml_doc.create_element('meta', charset: 'utf-8') if epub_version >= 3.0

    html.children.first.before(head)
  end

  # https://github.com/IDPF/epubcheck/issues/631
  if epub_version < 3.0
    xhtml_doc.internal_subset.remove unless xhtml_doc.internal_subset.nil?
    xhtml_doc.create_internal_subset('html', "-//W3C//DTD XHTML 1.1//EN", "http://www.w3.org/TR/xhtml11/DTD/xhtml11.dtd")
  end
end

.add_scripts(xhtml_doc, scripts) ⇒ Object

Method for adding scripts with links, method will not add duplicate items

Parameters:

  • xhtml_doc (Nokogiri::XML::Document) —

    input XML document to work with

  • styles (Array<String>) —

    links to files

Returns:

  • nil



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# File 'lib/epuber/compiler/xhtml_processor.rb', line 139

def self.add_scripts(xhtml_doc, scripts)
  head  = xhtml_doc.at_css('html > head')
  old_links = head.css('script').map { |node| node['src'] }

  links_to_add = scripts - old_links

  links_to_add.each do |path|
    head << xhtml_doc.create_element('script', src: path, type: 'text/javascript')
  end
end

.add_styles(xhtml_doc, styles) ⇒ Object

Method for adding style sheets with links, method will not add duplicate items

Parameters:

  • xhtml_doc (Nokogiri::XML::Document) —

    input XML document to work with

  • styles (Array<String>) —

    links to files

Returns:

  • nil



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# File 'lib/epuber/compiler/xhtml_processor.rb', line 121

def self.add_styles(xhtml_doc, styles)
  head  = xhtml_doc.at_css('html > head')
  old_links = head.css('link[rel="stylesheet"]').map { |node| node['href'] }

  links_to_add = styles - old_links

  links_to_add.each do |path|
    head << xhtml_doc.create_element('link', href: path, rel: 'stylesheet', type: 'text/css')
  end
end

.add_viewport(xhtml_doc, viewport_size) ⇒ Object

Adds viewport meta tag to head of some document, but only if there is not some existing tag

Parameters:

  • xhtml_doc (Nokogiri::XML::Document)
  • viewport_size (Epuber::Size) 


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# File 'lib/epuber/compiler/xhtml_processor.rb', line 155

def self.add_viewport(xhtml_doc, viewport_size)
  head = xhtml_doc.at_css('html > head')
  return unless head.at_css("meta[name='viewport']").nil?

  s = viewport_size
  head << xhtml_doc.create_element('meta', name: 'viewport', content: "width=#{s.width},height=#{s.height}")
end

.resolve_images(xhtml_doc, file_path, file_resolver) ⇒ Object

Returns nil.

Parameters:

  • xhtml_doc (Nokogiri::XML::Document)
  • file_path (String) —

    path of referring file

  • file_resolver (FileResolver)

Returns:

  • nil



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# File 'lib/epuber/compiler/xhtml_processor.rb', line 287

def self.resolve_images(xhtml_doc, file_path, file_resolver)
  resolve_resources_in('img', 'src', :image, xhtml_doc, file_path, file_resolver)
end

.resolve_links(xhtml_doc, file_path, file_finder) ⇒ Array<URI>

Resolves all links to files in XHTML document and returns the valid and resolved versions

Parameters:

  • xhtml_doc (Nokogiri::XML::Document) —

    input XML document to work with

  • file_path (String) —

    path to file from which is searching for other file

  • file_finder (Epuber::Compiler::FileFinder) —

    finder for searching for files

Returns:

  • (Array<URI>) —

    resolved links



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# File 'lib/epuber/compiler/xhtml_processor.rb', line 243

def self.resolve_links(xhtml_doc, file_path, file_finder)
  [
    resolve_links_for(xhtml_doc, 'a', 'href', :text, file_path, file_finder),
    resolve_links_for(xhtml_doc, 'map > area', 'href', :text, file_path, file_finder),
  ].flatten
end

.resolve_links_for(xhtml_doc, tag_name, attribute_name, groups, file_path, file_finder) ⇒ Array<URI>

Resolves all links to files in XHTML document and returns the valid and resolved versions

Parameters:

  • xhtml_doc (Nokogiri::XML::Document) —

    input XML document to work with

  • tag_name (String) —

    CSS selector for tag

  • attribute_name (String) —

    name of attribute

  • groups (Symbol | Array<Symbol>) —

    groups of the searching file, could be for example :image when searching for file from tag <img>

  • file_path (String) —

    path to file from which is searching for other file

  • file_finder (Epuber::Compiler::FileFinder) —

    finder for searching for files

Returns:

  • (Array<URI>) —

    resolved links



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# File 'lib/epuber/compiler/xhtml_processor.rb', line 210

def self.resolve_links_for(xhtml_doc, tag_name, attribute_name, groups, file_path, file_finder)
  founded_links = []

  xhtml_doc.css("#{tag_name}[#{attribute_name}]").each do |node|
    begin
      src = node[attribute_name]
      # @type [String] src

      next if src.nil?

      target_file = resolved_link_to_file(src, groups, file_path, file_finder)
      founded_links << target_file

      node[attribute_name] = target_file.to_s
    rescue UnparseableLinkError, FileFinders::FileNotFoundError, FileFinders::MultipleFilesFoundError => e
      UI.warning(e.to_s, location: node)

      # skip not found files
      next
    end
  end

  founded_links
end

.resolve_mathml_namespace(xhtml_doc) ⇒ Object 



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# File 'lib/epuber/compiler/xhtml_processor.rb', line 275

def self.resolve_mathml_namespace(xhtml_doc)
  xhtml_doc.css('math').each do |math_node|
    math_node.add_namespace('xmlns', 'http://www.w3.org/1998/Math/MathML')
  end
end

.resolve_resources_in(node_css_query, attribute_name, resource_group, xhtml_doc, file_path, file_resolver) ⇒ Object 



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# File 'lib/epuber/compiler/xhtml_processor.rb', line 311

def self.resolve_resources_in(node_css_query, attribute_name, resource_group, xhtml_doc, file_path, file_resolver)
  dirname = File.dirname(file_path)

  xhtml_doc.css(node_css_query).each do |img|
    path = img[attribute_name]
    next if path.nil?

    begin
      new_path = file_resolver.dest_finder.find_file(path, groups: resource_group, context_path: dirname)

    rescue UnparseableLinkError, FileFinders::FileNotFoundError, FileFinders::MultipleFilesFoundError
      begin
        new_path = resolved_link_to_file(path, resource_group, dirname, file_resolver.source_finder).to_s
        pkg_abs_path = File.expand_path(new_path, dirname).unicode_normalize
        pkg_new_path = Pathname.new(pkg_abs_path).relative_path_from(Pathname.new(file_resolver.source_path)).to_s

        file_class = FileResolver.file_class_for(File.extname(new_path))
        file = file_class.new(pkg_new_path)
        file.path_type = :manifest
        file_resolver.add_file(file)

        new_path = FileResolver::renamed_file_with_path(new_path)

      rescue UnparseableLinkError, FileFinders::FileNotFoundError, FileFinders::MultipleFilesFoundError => e
        UI.warning(e.to_s, location: img)

        next
      end
    end

    img[attribute_name] = new_path
  end
end

.resolve_scripts(xhtml_doc, file_path, file_resolver) ⇒ Object

Returns nil.

Parameters:

  • xhtml_doc (Nokogiri::XML::Document)
  • file_path (String) —

    path of referring file

  • file_resolver (FileResolver)

Returns:

  • nil



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# File 'lib/epuber/compiler/xhtml_processor.rb', line 297

def self.resolve_scripts(xhtml_doc, file_path, file_resolver)
  resolve_resources_in('script', 'src', :script, xhtml_doc, file_path, file_resolver)
end

.resolve_stylesheets(xhtml_doc, file_path, file_resolver) ⇒ Object

Returns nil.

Parameters:

  • xhtml_doc (Nokogiri::XML::Document)
  • file_path (String) —

    path of referring file

  • file_resolver (FileResolver)

Returns:

  • nil



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# File 'lib/epuber/compiler/xhtml_processor.rb', line 307

def self.resolve_stylesheets(xhtml_doc, file_path, file_resolver)
  resolve_resources_in('link[rel="stylesheet"]', 'href', :style, xhtml_doc, file_path, file_resolver)
end

.resolved_link_to_file(path, groups, file_path, file_finder) ⇒ URI

Method which will resolve path to file from pattern

Parameters:

  • path (String) —

    pattern or path of the file

  • groups (Symbol | Array<Symbol>) —

    groups of the searching file, could be for example :image when searching for file from tag <img>

  • file_path (String) —

    path to file from which is searching for other file

  • file_finder (Epuber::Compiler::FileFinder) —

    finder for searching for files

Returns:

  • (URI) —

    resolved path to file or remote web page

Raises:

  • UnparseableLinkError, FileFinder::FileNotFoundError, FileFinder::MultipleFilesFoundError



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# File 'lib/epuber/compiler/xhtml_processor.rb', line 174

def self.resolved_link_to_file(path, groups, file_path, file_finder)
  raise FileFinders::FileNotFoundError.new(path, file_path) if path.empty?

  begin
    uri = URI(path)
  rescue URI::InvalidURIError
    begin
      uri = URI(URI::encode(path))
    rescue URI::InvalidURIError
      # skip not valid uri
      raise UnparseableLinkError, "Unparseable link `#{path}`"
    end
  end

  # skip uri with scheme (links to web pages)
  return uri unless uri.scheme.nil?

  # skip empty path
  return uri if uri.path.empty? && !uri.fragment.nil? && !uri.fragment.empty?

  uri.path = file_finder.find_file(uri.path, groups: groups, context_path: file_path)

  uri
end

.using_javascript?(xhtml_doc) ⇒ Bool

Parameters:

  • xhtml_doc (Nokogiri::XML::Document) —

    input XML document to work with

Returns:

  • (Bool) 


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# File 'lib/epuber/compiler/xhtml_processor.rb', line 254

def self.using_javascript?(xhtml_doc)
  !xhtml_doc.at_css('script').nil?
end

.using_mathml?(xhtml_doc) ⇒ Bool

Parameters:

  • xhtml_doc (Nokogiri::XML::Document) —

    input XML document to work with

Returns:

  • (Bool) 


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# File 'lib/epuber/compiler/xhtml_processor.rb', line 271

def self.using_mathml?(xhtml_doc)
  !xhtml_doc.at_css('math|math', 'math' => 'http://www.w3.org/1998/Math/MathML').nil?
end

.using_remote_resources?(xhtml_doc) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/epuber/compiler/xhtml_processor.rb', line 258

def self.using_remote_resources?(xhtml_doc)
  regexp = %r{^[^:/?#]+://.*}

  result = false
  result ||= xhtml_doc.css('[src]').any? { |node| node['src'] =~ regexp }
  result ||= xhtml_doc.css('link[href]').any? { |node| node['href'] =~ regexp }
  result
end

.xml_document_from_string(text, file_path = nil) ⇒ Nokogiri::XML::Document

Method for parsing incomplete XML, supports multiple root elements

Parameters:

  • text (String) —

    input XHTML text

Returns:

  • (Nokogiri::XML::Document) —

    parsed document



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# File 'lib/epuber/compiler/xhtml_processor.rb', line 22

def self.xml_document_from_string(text, file_path = nil)
  if /\A[\n\r ]+(<\?xml)/ =~ text
    UI.warning('XML header must be at the beginning of document', location: UI::Location.new(file_path, 1))

    text = text.lstrip
  end

  xml_header = ''
  if /\A\s*(<\?xml[^>]*\?>)/ =~ text
    match = Regexp.last_match
    xml_header = text[match.begin(1)...match.end(1)]
    text[match.begin(1)...match.end(1)] = ''
  end

  doctypes = []
  while /(\n|\?>|\A)?(<!DOCTYPE [^>]*>\n*)/ =~ text
    doctypes << $2.strip

    match = Regexp.last_match
    text[match.begin(2)...match.end(2)] = ''
  end

  before = ([xml_header] + doctypes).compact.join("\n")
  unless before.empty?
    before = before + "\n"
  end

  parse_options = Nokogiri::XML::ParseOptions::DEFAULT_XML |
                  Nokogiri::XML::ParseOptions::NOERROR | # to silence any errors or warnings printing into console
                  Nokogiri::XML::ParseOptions::NOWARNING

  doc = Nokogiri::XML("#{before}<root>#{text}</root>", nil, nil, parse_options)
  doc.encoding = 'UTF-8'
  doc.file_path = file_path

  root = root_node = doc.root
  root_elements = root.children.select { |a| a.element? || a.comment? }

  if root_elements.count == 1
    doc.root = root_elements.first
  elsif root_node.at_css('body').nil?
    root_node.node_name = 'body'
  end

  doc
end