Class: Boilerpipe::SAX::HTMLContentHandler

Inherits:
Nokogiri::XML::SAX::Document
  • Object
show all
Defined in:
lib/boilerpipe/sax/html_content_handler.rb

Constant Summary collapse

ANCHOR_TEXT_START = 
"$\ue00a<"
ANCHOR_TEXT_END = 
">\ue00a$"
VALID_WORD_CHARACTER = 
/[\p{L}\p{Nd}\p{Nl}\p{No}]/

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ HTMLContentHandler

Returns a new instance of HTMLContentHandler.



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 9

def initialize
  @label_stacks = []
  @tag_actions = ::Boilerpipe::SAX::TagActionMap.tag_actions
  @tag_level = 0
  @sb_last_was_whitespace = false
  @text_buffer = ''
  @token_buffer = ''
  @offset_blocks = 0
  @flush = false
  @block_tag_level = -1

  @in_body_tag = 0
  @in_anchor_tag = 0
  @in_ignorable_element = 0
  @in_anchor_text = false
  @font_size_stack = []
  @last_start_tag = ''
  @title
  @text_blocks = []
end

Instance Attribute Details

#font_size_stack ⇒ Object

Returns the value of attribute font_size_stack.



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 5

def font_size_stack
  @font_size_stack
end

#in_anchor_tag ⇒ Object

Returns the value of attribute in_anchor_tag.



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 5

def in_anchor_tag
  @in_anchor_tag
end

#in_ignorable_element ⇒ Object (readonly)

Returns the value of attribute in_ignorable_element.



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 3

def in_ignorable_element
  @in_ignorable_element
end

#label_stacks ⇒ Object (readonly)

Returns the value of attribute label_stacks.



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 3

def label_stacks
  @label_stacks
end

#last_start_tag ⇒ Object (readonly)

Returns the value of attribute last_start_tag.



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 3

def last_start_tag
  @last_start_tag
end

#token_buffer ⇒ Object

Returns the value of attribute token_buffer.



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 5

def token_buffer
  @token_buffer
end

Instance Method Details

#add_label_action(label_action) ⇒ Object 



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 261

def add_label_action(label_action)
  label_stack = @label_stacks.last
  if label_stack.nil?
    label_stack = []
    @label_stacks.pop
    @label_stacks << label_stack
  end
  label_stack << label_action
end

#add_text_block(text_block) ⇒ Object 



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 230

def add_text_block(text_block)
  @label_stacks.each do |stack|
    next unless stack

    stack.each do |label_action|
      text_block.add_label(label_action.labels) if label_action
    end
  end
  @text_blocks << text_block
end

#append_space ⇒ Object

append space if last character wasn’t already one



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 242

def append_space
  return if @sb_last_was_whitespace

  @sb_last_was_whitespace = true

  @text_buffer << ' '
  @token_buffer << ' '
end

#append_text(text) ⇒ Object 



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 251

def append_text(text)
  @sb_last_was_whitespace = false
  @text_buffer << text
  @token_buffer << text
end

#append_token(token) ⇒ Object 



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 257

def append_token(token)
  @token_buffer << token
end

#characters(text) ⇒ Object 



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 47

def characters(text)
  flush_block if @flush

  return if in_ignorable_element?
  return if text.empty?

  # replace all whitespace with simple space
  text.gsub!(/\s+/, ' ')

  # trim whitespace
  started_with_whitespace = text =~ /^\s/
  ended_with_whitespace = text =~ /\s$/
  text.strip!

  #  add a single space if the block was only whitespace
  if text.empty?
    append_space
    @last_event = :WHITESPACE
    return
  end

  # set block levels
  @block_tag_level = @tag_level if @block_tag_level == -1

  append_space if started_with_whitespace
  append_text(text)
  append_space if ended_with_whitespace

  @last_event = :CHARACTERS
end

#decrease_in_ignorable_element! ⇒ Object

should we prevent less than zero here?



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 210

def decrease_in_ignorable_element!
  @in_ignorable_element -= 1
end

#end_element(name) ⇒ Object 



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 78

def end_element(name)
  tag = name.upcase.intern
  tag_action = @tag_actions[tag]
  if tag_action
    @flush = tag_action.end_tag(self, name) | @flush
  else
    @flush = true
  end

  @tag_level -= 1 if tag_action.nil? || tag_action.changes_tag_level?
  flush_block if @flush

  @last_event = :END_TAG
  @last_end_tag = tag
  @label_stacks.pop
end

#enter_body_tag! ⇒ Object 



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 214

def enter_body_tag!
  @in_body_tag += 1
end

#exit_body_tag! ⇒ Object 



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 218

def exit_body_tag!
  @in_body_tag -= 1
end

#flush_block ⇒ Object 



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 99

def flush_block
  @flush = false

  # set title
  if not_in_body_tag?
    @title = @token_buffer.strip if :TITLE == @last_start_tag
    clear_buffers
    return
  end

  # clear out if empty or just a space
  length = @token_buffer.size
  case length
  when 0
    return
  when 1
    clear_buffers if @sb_last_was_whitespace
    return
  end

  num_tokens = 0
  num_words = 0
  num_words_current_line = 0
  num_words_in_wrapped_lines = 0
  num_wrapped_lines = 0
  num_linked_words = 0
  current_line_length = 0
  max_line_length = 80

  tokens = ::Boilerpipe::UnicodeTokenizer.tokenize(@token_buffer)
  tokens.each do |token|
    if ANCHOR_TEXT_START == token
      @in_anchor_text = true
    elsif ANCHOR_TEXT_END == token
      @in_anchor_text = false
    elsif is_word?(token)
      num_tokens += 1
      num_words += 1
      num_words_current_line += 1
      num_linked_words += 1 if @in_anchor_text
      token_length = token.size
      current_line_length += token_length + 1

      if current_line_length > max_line_length
        num_wrapped_lines += 1
        current_line_length = token_length
        num_words_current_line = 1
      end
    else
      num_tokens += 1
    end
  end

  return if num_tokens == 0

  num_words_in_wrapped_lines = 0
  if num_wrapped_lines == 0
    num_words_in_wrapped_lines = num_words
    num_wrapped_lines = 1
  else
    num_words_in_wrapped_lines = num_words - num_words_current_line
  end

  text_block = ::Boilerpipe::Document::TextBlock.new(@text_buffer.strip,
                                                     num_words,
                                                     num_linked_words,
                                                     num_words_in_wrapped_lines,
                                                     num_wrapped_lines, @offset_blocks)

  @offset_blocks += 1
  clear_buffers
  text_block.set_tag_level(@block_tag_level)
  add_text_block(text_block)
  @block_tag_level = -1
end

#in_anchor_tag? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 226

def in_anchor_tag?
  @in_anchor_tag > 0
end

#in_ignorable_element? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 222

def in_ignorable_element?
  @in_ignorable_element > 0
end

#increase_in_ignorable_element! ⇒ Object

public void flushBlock() 

int numWords = 0;
int numLinkedWords = 0;
int numWrappedLines = 0;
int currentLineLength = -1; // don't count the first space
final int maxLineLength = 80;
int numTokens = 0;
int numWordsCurrentLine = 0;




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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 205

def increase_in_ignorable_element!
  @in_ignorable_element += 1
end

#is_word?(word) ⇒ Boolean

unicode regex - categories pL – Letter pNd – a decimal digit pNl – a letterlike numeric character pNo – a numeric character of other type

Returns:

  • (Boolean) 


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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 191

def is_word?(word)
  word =~ VALID_WORD_CHARACTER
end

#not_in_body_tag? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 95

def not_in_body_tag?
  @in_body_tag == 0
end

#start_element(name, attrs = []) ⇒ Object 



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 30

def start_element(name, attrs = [])
  @label_stacks << nil
  tag = name.upcase.intern

  tag_action = @tag_actions[tag]
  if tag_action
    @tag_level += 1 if tag_action.changes_tag_level?
    @flush = tag_action.start(self, name, attrs) | @flush
  else
    @tag_level += 1
    @flush = true
  end

  @last_event = :START_TAG
  @last_start_tag = tag
end

#text_document ⇒ Object 



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 175

def text_document
  flush_block
  ::Boilerpipe::Document::TextDocument.new(@title, @text_blocks)
end

#token_buffer_size ⇒ Object 



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# File 'lib/boilerpipe/sax/html_content_handler.rb', line 180

def token_buffer_size
  @token_buffer.size
end