gistfile1.txt

# Ruby on Rails truncate_html HTML截断并保持HTML标签不出错
# HTML截断并保持HTML标签不出错
# 可以放入 application_helper.rb 里面
# 前台调用 truncate_html(html_text,:length => 1000)
def truncate_html(html, options={})
  # Does not behave identical to current Rails truncate method i.e. you must pass options as a hash not just values
  # Sample usage: <%= html_truncate(category.description, :length => 120, :omission => "(continued...)" ) -%>...
  previous_tag = ""
  text, result = [], []
  
  # get all text (including punctuation) and tags and stick them in a hash
  html.scan(/<\/?[^>]*>|[A-Za-z.,;!"'?]+/).each { |t| text << t }
  
  text.each do |str|
    if options[:length] > 0
      if str =~ /<\/?[^>]*>/
        previous_tag = str
        result << str
      else
        result << str
        options[:length] -= str.length
      end
    else
      # now stick the next tag with a </> that matches the previous open tag on the end of the result 
      if str =~ /<\/([#{previous_tag}]*)>/
        result << str
      else
      end
    end
  end
  return result.join(" ") + options[:omission].to_s
end