Underpants Gnome

[UPDATE 2007-01-10] I’ve updated the scrubber, see Hpricot Scrub for more. [/UPDATE]

I went looking for a Ruby replacement for Html::Scrubber in perl for a gig and came up blank. Can it really be possible the nobody is doing anything more than blindly stripping tags?

I had seen Hpricot and thought I needed to find a reason to use it, well here it is. I monkey patched a couple methods into Hrpicot and off I went.

Here’s the Hpricot bits.

module Hpricot
  class Elements
    def strip
      each { |x| x.strip }
    end

    def strip_attributes(safe=[], patterns={})
      each { |x| x.strip_attributes(safe, patterns) }
    end
  end

  class Elem
    def strip
      parent.replace_child self, Hpricot.make(inner_html) unless 
        parent.nil?
    end

    def strip_attributes(safe=[], patterns={})
      attributes.each { |atr|
          pat = patterns[atr[0].to_sym] || ''
          remove_attribute(atr[0]) unless safe.include?(atr[0]) &&
            atr[1].match(pat)
      } unless attributes.nil?
    end
  end
end

Just that bit get’s me to the point where I can do things like this

doc = Hpricot(open('http://slashdot.org/').read)

# remove all anchors leaving behind the text inside.
(doc/:a).strip 

# strip all attributes except for src from all images
(doc/:img).strip_attributes(['src']) 

Then I made scrubber that passes in the array and hash to those methods to handle the dirty work. It looks like this, though I’m also using Tidy so mine is alittle different.

class HtmlScrubber
  @@config = YAML.load_file(
    "#{RAILS_ROOT}/config/html_scrubber.yml") unless 
      defined?(@@config)

  def self.scrub(markup)
    doc = Hpricot(markup || '', :xhtml_strict => true)
    raise 'No markup specified' if doc.nil?
    @@config[:nuke_tags].each { |tag| (doc/tag).remove }
    @@config[:allow_tags].each { |tag|
      (doc/tag).strip_attributes(@@config[:allow_attributes], 
        @@config[:attribute_patterns]) }
    doc.traverse_all_element {|e|
      e.strip unless @@config[:allow_tags].include?(e.name)
    }
    doc.inner_html
  end
end

Here is a zip of the code and a sample config: html_scrubber.zip

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I wanted to do some profiling of a Rails app, so I did a little digging and found ruby-prof with new and improved call graphs. Plus it’s very fast. The install couldn’t be easier

sudo gem install ruby-prof

Then I wanted to see if I could get this to run in before and after filters, I haven’t had any luck, though I haven’t tried all that hard. Since I wanted to be able to do this relatively easily I threw together a mini module to handle the report generation piece for me. So now I can profile a controller action by adding this to my application controller

require 'ruby_profiler'

class ApplicationController < ActionController::Base
  include RubyProfiler
end

Then in the controller I just need to

def some_action
  result = RubyProf.profile {
    ...
  }
  write_profile(result, 5, RubyProfiler::GRAPH_HTML)
end

source: ruby_profiler.rb

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Ok, so the project I’ve been workig on is getting close…

Feed Harvest if you are interested in the (very) private beta, let us know.

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I’ve been reading all this great stuff about Ruby on Rails so I told my boss that we should look into it, then I expensed a copy of Agile web Development with Rails and gave it a read. It looked promising.

I read a post on the Rails blog the other day about integrating FCKeditor with Rails and thought that would be a nice addition, unfortunately the method mentioned was little more than how to drop tags in a page to get FCKeditor to go. There wasn’t any real Rails to it.

I decided that would make a somewhat interesting project to start playing with Rails as it needs to interact with the file system a little. So I spent the past day-and-a-halfish building FCKeditor on Rails, it’s a little rough around the edges and I still want to integrate the mcpuk File Browser becasue it has so much more functionality than the default.

The end result is a Rails helper/controller that lets you add an FCKeditor instance just like you would expect in Rails:

fckeditor(:object, :param, {:width => '600px', :height => '500px'})

not to shabby. Now we will see how long it takes me to get around to adding mcpuk support.

The source can also be found in the FCKeditor trac project.

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So I spent some time this weekend putting together a PHP Class to wrap around the swish-e search engine. It handles most of the settings you would want to set and also takes care of showing highlighted contextual results, providing you used StoreDescription when you built the index.

When I get it a little more ironed out I’ll cut it loose, providing anybody gives a rip.

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