Class: TruncatedSaxDocument

Inherits:
Nokogiri::XML::SAX::Document
  • Object
show all
Defined in:
lib/abbreviato/truncated_sax_document.rb

Constant Summary collapse

IGNORABLE_TAGS = 
%w[html head body].freeze
VOID_TAGS =

These don’t have to be closed (which also impacts ongoing length calculations) www.456bereastreet.com/archive/201005/void_empty_elements_and_self-closing_start_tags_in_html/

%w[area base br col command hr img input keygen link meta param source wbr].freeze

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options) ⇒ TruncatedSaxDocument

FIXME: Call super to initialize state of the parent class.



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# File 'lib/abbreviato/truncated_sax_document.rb', line 20

def initialize(options) # rubocop:disable Lint/MissingSuper
  @html_coder = HTMLEntities.new

  @max_length = options[:max_length]
  @tail = options[:tail] || ''
  @fragment_mode = options[:fragment]

  @truncated_string = ''
  @closing_tags = []
  @estimated_length = 0
  @ignored_levels = 0
  @truncated = false
end

Instance Attribute Details

#ignored_levels ⇒ Object (readonly)

Returns the value of attribute ignored_levels.



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# File 'lib/abbreviato/truncated_sax_document.rb', line 13

def ignored_levels
  @ignored_levels
end

#max_length ⇒ Object (readonly)

Returns the value of attribute max_length.



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# File 'lib/abbreviato/truncated_sax_document.rb', line 13

def max_length
  @max_length
end

#tail ⇒ Object (readonly)

Returns the value of attribute tail.



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# File 'lib/abbreviato/truncated_sax_document.rb', line 13

def tail
  @tail
end

#truncated ⇒ Object (readonly)

Returns the value of attribute truncated.



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# File 'lib/abbreviato/truncated_sax_document.rb', line 13

def truncated
  @truncated
end

#truncated_string ⇒ Object (readonly)

Returns the value of attribute truncated_string.



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# File 'lib/abbreviato/truncated_sax_document.rb', line 13

def truncated_string
  @truncated_string
end

Instance Method Details

#cdata_block(string) ⇒ Object

This method is called when the parser encounters cdata. In practice, this also gets called for this style of comment inside an element:

<style><!--
  /* Font Definitions */
  @font-face
    {font-family:Wingdings;
    panose-1:5 0 0 0 0 0 0 0 0 0;}
--></style>



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# File 'lib/abbreviato/truncated_sax_document.rb', line 103

def cdata_block(string)
  if string.bytesize <= remaining_length
    append_to_truncated_string(string)
  else
    @truncated = true
  end
end

#characters(decoded_string) ⇒ Object

This method is called when the parser encounters characters between tags



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# File 'lib/abbreviato/truncated_sax_document.rb', line 64

def characters(decoded_string)
  if max_length_reached? || ignore_mode?
    @truncated = true
    return
  end

  # Use encoded length, so &gt; counts as 4 bytes, not 1 (which is what '>' would give)
  encoded_string = @html_coder.encode(decoded_string, :named)
  string_to_append = if encoded_string.bytesize > remaining_length
                       # This is the line which prevents HTML entities getting truncated - treat them as a single char
                       str = truncate_string(decoded_string)
                       str << tail if remaining_length - str.bytesize >= tail.bytesize
                       str
                     else
                       encoded_string
                     end
  append_to_truncated_string(string_to_append)
end

#comment(string) ⇒ Object

This method is called when the parser encounters a comment



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# File 'lib/abbreviato/truncated_sax_document.rb', line 84

def comment(string)
  comment = comment_tag(string)
  if comment.bytesize <= remaining_length
    append_to_truncated_string(comment)
  else
    @truncated = true
  end
end

#end_document ⇒ Object 



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# File 'lib/abbreviato/truncated_sax_document.rb', line 130

def end_document
  @closing_tags.reverse_each { |name| append_to_truncated_string(closing_tag(name), 0) }
end

#end_element(name) ⇒ Object

This method is called when the parser encounters a closing tag



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# File 'lib/abbreviato/truncated_sax_document.rb', line 112

def end_element(name)
  if ignore_mode?
    exit_ignored_level(name)
    return
  end

  # Note that any remaining end tags get added automatically (in `end_document`) as the document is closed
  return if max_length_reached? || ignorable_tag?(name)

  # FIXME: Style/GuardClause: Use a guard clause (return if single_tag_element?(name)) instead of wrapping the code inside a conditional expression. (https://rubystyle.guide#no-nested-conditionals)
  unless single_tag_element?(name) # rubocop:disable Style/GuardClause
    @closing_tags.pop
    # Don't count the length when closing a tag - it was accommodated when
    # the tag was opened
    append_to_truncated_string(closing_tag(name), 0)
  end
end

#start_element(name, attributes) ⇒ Object

This method is called when the parser encounters an open tag



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# File 'lib/abbreviato/truncated_sax_document.rb', line 35

def start_element(name, attributes)
  if max_length_reached? || ignorable_tag?(name)
    @truncated = true if max_length_reached?
    return
  end

  # If already in ignore mode, go in deeper
  if ignore_mode?
    enter_ignored_level(name)
    return
  end

  string_to_add = opening_tag(name, attributes)

  # Abort if there is not enough space to add the combined opening tag and (potentially) the closing tag
  length_of_tags = overridden_tag_length(name, string_to_add)
  if length_of_tags > remaining_length
    @truncated = true
    enter_ignored_level(name)
    return
  end

  # Save the tag so we can push it on at the end
  @closing_tags.push name unless single_tag_element?(name)

  append_to_truncated_string(string_to_add, length_of_tags)
end