module Kramdown::Parser::Html::Parser

Contains the parsing methods. This module can be mixed into any parser to get HTML parsing functionality. The only thing that must be provided by the class are instance variable @stack for storing the needed state and @src (instance of StringScanner) for the actual parsing.

Public Instance Methods

handle_html_start_tag(line = nil) { |el, closed, handle_body| ... } click to toggle source

Process the HTML start tag that has already be scanned/checked via @src.

Does the common processing steps and then yields to the caller for further processing (first parameter is the created element; the second parameter is true if the HTML element is already closed, ie. contains no body; the third parameter specifies whether the body - and the end tag - need to be handled in case closed=false).

# File lib/kramdown/parser/html.rb, line 87
def handle_html_start_tag(line = nil) # :yields: el, closed, handle_body
  name = @src[1]
  name.downcase! if HTML_ELEMENT[name.downcase]
  closed = !@src[4].nil?
  attrs = parse_html_attributes(@src[2], line, HTML_ELEMENT[name])

  el = Element.new(:html_element, name, attrs, category: :block)
  el.options[:location] = line if line
  @tree.children << el

  if !closed && HTML_ELEMENTS_WITHOUT_BODY.include?(el.value)
    closed = true
  end
  if name == 'script' || name == 'style'
    handle_raw_html_tag(name)
    yield(el, false, false)
  else
    yield(el, closed, true)
  end
end

handle_raw_html_tag(name) click to toggle source

Handle the raw HTML tag at the current position.

# File lib/kramdown/parser/html.rb, line 127
def handle_raw_html_tag(name)
  curpos = @src.pos
  if @src.scan_until(/(?=<\/#{name}\s*>)/mi)
    add_text(extract_string(curpos...@src.pos, @src), @tree.children.last, :raw)
    @src.scan(HTML_TAG_CLOSE_RE)
  else
    add_text(@src.rest, @tree.children.last, :raw)
    @src.terminate
    warning("Found no end tag for '#{name}' - auto-closing it")
  end
end

parse_html_attributes(str, line = nil, in_html_tag = true) click to toggle source

Parses the given string for HTML attributes and returns the resulting hash.

If the optional line parameter is supplied, it is used in warning messages.

If the optional in_html_tag parameter is set to false, attributes are not modified to contain only lowercase letters.

# File lib/kramdown/parser/html.rb, line 114
def parse_html_attributes(str, line = nil, in_html_tag = true)
  attrs = {}
  str.scan(HTML_ATTRIBUTE_RE).each do |attr, val, _sep, quoted_val|
    attr.downcase! if in_html_tag
    if attrs.key?(attr)
      warning("Duplicate HTML attribute '#{attr}' on line #{line || '?'} - overwriting previous one")
    end
    attrs[attr] = val || quoted_val || ""
  end
  attrs
end

parse_raw_html(el, &block) click to toggle source

Parse raw HTML from the current source position, storing the found elements in el. Parsing continues until one of the following criteria are fulfilled:

The end of the document is reached.
The matching end tag for the element el is found (only used if el is an HTML element).

When an HTML start tag is found, processing is deferred to handle_html_start_tag, providing the block given to this method.

# File lib/kramdown/parser/html.rb, line 150
def parse_raw_html(el, &block)
  @stack.push(@tree)
  @tree = el

  done = false
  while !@src.eos? && !done
    if (result = @src.scan_until(HTML_RAW_START))
      add_text(result, @tree, :text)
      line = @src.current_line_number
      if (result = @src.scan(HTML_COMMENT_RE))
        @tree.children << Element.new(:xml_comment, result, nil, category: :block, location: line)
      elsif (result = @src.scan(HTML_INSTRUCTION_RE))
        @tree.children << Element.new(:xml_pi, result, nil, category: :block, location: line)
      elsif @src.scan(HTML_CDATA_RE)
        @tree.children << Element.new(:text, @src[1], nil, cdata: true, location: line)
      elsif @src.scan(HTML_TAG_RE)
        if method(:handle_html_start_tag).arity.abs >= 1
          handle_html_start_tag(line, &block)
        else
          handle_html_start_tag(&block) # DEPRECATED: method needs to accept line number in 2.0
        end
      elsif @src.scan(HTML_TAG_CLOSE_RE)
        if @tree.value == (HTML_ELEMENT[@tree.value] ? @src[1].downcase : @src[1])
          done = true
        else
          add_text(@src.matched, @tree, :text)
          warning("Found invalidly used HTML closing tag for '#{@src[1]}' on " \
                  "line #{line} - ignoring it")
        end
      else
        add_text(@src.getch, @tree, :text)
      end
    else
      add_text(@src.rest, @tree, :text)
      @src.terminate
      if @tree.type == :html_element
        warning("Found no end tag for '#{@tree.value}' on line " \
                "#{@tree.options[:location]} - auto-closing it")
      end
      done = true
    end
  end

  @tree = @stack.pop
end