class Nokogiri::HTML4::Document - nokogiri-1.15.2 Documentation

# class Nokogiri::HTML4::Document

### Public Class Methods

parse(string_or_io, url = nil, encoding = nil, options = XML::ParseOptions::DEFAULT_HTML) { |options| ... } click to toggle source

Parse `HTML`. `string_or_io` may be a String, or any object that responds to read and close such as an IO, or StringIO. `url` is resource where this document is located. `encoding` is the encoding that should be used when processing the document. `options` is a number that sets options in the parser, such as Nokogiri::XML::ParseOptions::RECOVER. See the constants in `Nokogiri::XML::ParseOptions`.

    # File lib/nokogiri/html4/document.rb, line 172
    def parse(string_or_io, url = nil, encoding = nil, options = XML::ParseOptions::DEFAULT_HTML)
      options = Nokogiri::XML::ParseOptions.new(options) if Integer === options
      yield options if block_given?

      url ||= string_or_io.respond_to?(:path) ? string_or_io.path : nil

      if string_or_io.respond_to?(:encoding)
        unless string_or_io.encoding == Encoding::ASCII_8BIT
          encoding ||= string_or_io.encoding.name
        end
      end

      if string_or_io.respond_to?(:read)
        if string_or_io.is_a?(Pathname)
          # resolve the Pathname to the file and open it as an IO object, see #2110
          string_or_io = string_or_io.expand_path.open
          url ||= string_or_io.path
        end

        unless encoding
          string_or_io = EncodingReader.new(string_or_io)
          begin
            return read_io(string_or_io, url, encoding, options.to_i)
          rescue EncodingReader::EncodingFound => e
            encoding = e.found_encoding
          end
        end
        return read_io(string_or_io, url, encoding, options.to_i)
      end

      # read_memory pukes on empty docs
      if string_or_io.nil? || string_or_io.empty?
        return encoding ? new.tap { |i| i.encoding = encoding } : new
      end

      encoding ||= EncodingReader.detect_encoding(string_or_io)

      read_memory(string_or_io, url, encoding, options.to_i)
    end

### Public Instance Methods

fragment(tags = nil) click to toggle source

Create a `Nokogiri::XML::DocumentFragment` from `tags`

    # File lib/nokogiri/html4/document.rb, line 149
    def fragment(tags = nil)
      DocumentFragment.new(self, tags, root)
    end

meta_encoding() click to toggle source

Get the meta tag encoding for this document. If there is no meta tag, then nil is returned.

    # File lib/nokogiri/html4/document.rb, line 12
    def meta_encoding
      if (meta = at_xpath("//meta[@charset]"))
        meta[:charset]
      elsif (meta = meta_content_type)
        meta["content"][/charset\s*=\s*([\w-]+)/i, 1]
      end
    end

meta_encoding=(encoding) click to toggle source

Set the meta tag encoding for this document.

If an meta encoding tag is already present, its content is replaced with the given text.

Otherwise, this method tries to create one at an appropriate place supplying head and/or html elements as necessary, which is inside a head element if any, and before any text node or content element (typically <body>) if any.

The result when trying to set an encoding that is different from the document encoding is undefined.

Beware in CRuby, that libxml2 automatically inserts a meta tag into a head element.

    # File lib/nokogiri/html4/document.rb, line 36
    def meta_encoding=(encoding)
      if (meta = meta_content_type)
        meta["content"] = format("text/html; charset=%s", encoding)
        encoding
      elsif (meta = at_xpath("//meta[@charset]"))
        meta["charset"] = encoding
      else
        meta = XML::Node.new("meta", self)
        if (dtd = internal_subset) && dtd.html5_dtd?
          meta["charset"] = encoding
        else
          meta["http-equiv"] = "Content-Type"
          meta["content"] = format("text/html; charset=%s", encoding)
        end

        if (head = at_xpath("//head"))
          head.prepend_child(meta)
        else
          set_metadata_element(meta)
        end
        encoding
      end
    end

serialize(options = {}) click to toggle source

Serialize Node using `options`. Save options can also be set using a block.

See also `Nokogiri::XML::Node::SaveOptions` and Node.

These two statements are equivalent:

    node.serialize(:encoding => 'UTF-8', :save_with => FORMAT | AS_XML)

or

    node.serialize(:encoding => 'UTF-8') do |config|
      config.format.as_xml
    end

Calls superclass method

    # File lib/nokogiri/html4/document.rb, line 142
    def serialize(options = {})
      options[:save_with] ||= XML::Node::SaveOptions::DEFAULT_HTML
      super
    end

title() click to toggle source

Get the title string of this document. Return nil if there is no title tag.

    # File lib/nokogiri/html4/document.rb, line 70
    def title
      (title = at_xpath("//title")) && title.inner_text
    end

title=(text) click to toggle source

Set the title string of this document.

If a title element is already present, its content is replaced with the given text.

Otherwise, this method tries to create one at an appropriate place supplying head and/or html elements as necessary, which is inside a head element if any, right after a meta encoding/charset tag if any, and before any text node or content element (typically <body>) if any.

    # File lib/nokogiri/html4/document.rb, line 85
    def title=(text)
      tnode = XML::Text.new(text, self)
      if (title = at_xpath("//title"))
        title.children = tnode
        return text
      end

      title = XML::Node.new("title", self) << tnode
      if (head = at_xpath("//head"))
        head << title
      elsif (meta = (at_xpath("//meta[@charset]") || meta_content_type))
        # better put after charset declaration
        meta.add_next_sibling(title)
      else
        set_metadata_element(title)
      end
    end

xpath_doctype() → Nokogiri::CSS::XPathVisitor::DoctypeConfig click to toggle source

Returns

  The document type which determines CSS-to-XPath translation.

See XPathVisitor for more information.

    # File lib/nokogiri/html4/document.rb, line 159
    def xpath_doctype
      Nokogiri::CSS::XPathVisitor::DoctypeConfig::HTML4
    end

### Private Instance Methods

meta_content_type() click to toggle source

    # File lib/nokogiri/html4/document.rb, line 60
    def meta_content_type
      xpath("//meta[@http-equiv and boolean(@content)]").find do |node|
        node["http-equiv"] =~ /\AContent-Type\z/i
      end
    end

set_metadata_element(element) click to toggle source

    # File lib/nokogiri/html4/document.rb, line 103
    def set_metadata_element(element) # rubocop:disable Naming/AccessorMethodName
      if (head = at_xpath("//head"))
        head << element
      elsif (html = at_xpath("//html"))
        head = html.prepend_child(XML::Node.new("head", self))
        head.prepend_child(element)
      elsif (first = children.find do |node|
               case node
               when XML::Element, XML::Text
                 true
               end
             end)
        # We reach here only if the underlying document model
        # allows <html>/<head> elements to be omitted and does not
        # automatically supply them.
        first.add_previous_sibling(element)
      else
        html = add_child(XML::Node.new("html", self))
        head = html.add_child(XML::Node.new("head", self))
        head.prepend_child(element)
      end
    end