Parse Technorati-style Tags from HTML

canadaduane (Duane Johnson) — Sat, 25 Mar 2006 02:02:46 GMT

An enhancement to the String class that parses out Technorati-style tags. Uses Typo's strip_html method to remove img tags and other markup.



class String

  # Strips any html markup from a string

  TYPO_TAG_KEY = TYPO_ATTRIBUTE_KEY = /[\w:_-]+/

  TYPO_ATTRIBUTE_VALUE = /(?:[A-Za-z0-9]+|(?:'[^']*?'|"[^"]*?"))/

  TYPO_ATTRIBUTE = /(?:#{TYPO_ATTRIBUTE_KEY}(?:\s*=\s*#{TYPO_ATTRIBUTE_VALUE})?)/

  TYPO_ATTRIBUTES = /(?:#{TYPO_ATTRIBUTE}(?:\s+#{TYPO_ATTRIBUTE})*)/

  TAG = %r{<[!/?\[]?(?:#{TYPO_TAG_KEY}|--)(?:\s+#{TYPO_ATTRIBUTES})?\s*(?:[!/?\]]+|--)?>}

  def strip_html

    self.gsub(TAG, '').gsub(/\s+/, ' ').strip

  end



  def tags

    scan(/]*\s*rel=\s*(.?)tag\1[^>]*>(.+?)<\/a>/i).

    map { |match| match.last.strip_html rescue nil }.

    compact.select { |s| !s.strip.empty? }

  end

end



# Example usage



s = %{civil war  iraq }



s.tags

# => ["civil war", "iraq"]

DZone Snippets: tags code

Parse Technorati-style Tags from HTML