Class: Card::Content::Parser

Inherits:
Object
  • Object
show all
Defined in:
lib/card/content/parser.rb

Instance Method Summary collapse

Constructor Details

#initialize(chunk_list) ⇒ Parser

Returns a new instance of Parser.



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# File 'lib/card/content/parser.rb', line 6

def initialize chunk_list
  @chunk_list = chunk_list
end

Instance Method Details

#parse(content, content_object) ⇒ Object 



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# File 'lib/card/content/parser.rb', line 9

def parse content, content_object
  chunks = []
  return chunks unless content.is_a? String

  position = last_position = 0
  prefix_regexp = Chunk.get_prefix_regexp @chunk_list
  interval_string = ''

  while (prefix_match = content[position..-1].match(prefix_regexp))
    prefix = prefix_match[0]
    # prefix of matched chunk
    chunk_start = prefix_match.begin(0) + position
    # content index of beginning of chunk
    if prefix_match.begin(0) > 0
      # if matched chunk is not beginning of test string
      interval_string += content[position..chunk_start - 1]
      # hold onto the non-chunk part of the string
    end

    chunk_class = Chunk.find_class_by_prefix prefix
    # get the chunk class from the prefix
    match, offset =
      chunk_class.full_match content[chunk_start..-1], prefix
    # see whether the full chunk actually matches
    # (as opposed to bogus prefix)
    context_ok = chunk_class.context_ok? content, chunk_start
    # make sure there aren't contextual reasons for ignoring this chunk
    position = chunk_start
    # move scanning position up to beginning of chunk

    if match
      # we have a chunk match
      position += (match.end(0) - offset.to_i)
      # move scanning position up to end of chunk
      if context_ok
        chunks << interval_string unless interval_string.empty?
        # add the nonchunk string to the chunk list
        chunks << chunk_class.new(match, content_object)
        # add the chunk to the chunk list
        interval_string = ''
        # reset interval string for next go-round
        last_position = position
        # note that the end of the chunk was the last place where a
        # chunk was found (so far)
      end
    else
      position += 1
      # no match.  look at the next character
    end

    next unless !match || !context_ok
    interval_string += content[chunk_start..position - 1]
    # moving beyond the alleged chunk.
    # append failed string to "nonchunk" string
  end

  if chunks.any? && last_position < content.size
    remainder = content[last_position..-1]
    # handle any leftover nonchunk string at the end of content
    chunks << remainder
  end

  chunks
end