Pulling avatars from twitter in a Rails App

Something which may be of use to all bloggers and social app builders is that it is pretty easy to pull someones twitter profile photo in RoR heres the code :

# call the twitter api
url = 'http://twitter.com/users/show/show.xml?email='+CGI.escape(test@test.test)

# get the XML data as a string
xml_data = Net::HTTP.get_response(URI.parse(url)).body

# extract profile image tag information
doc = REXML::Document.new(xml_data)
profile_image = nil
doc.elements.each('user/profile_image_url') do |ele|
        profile_image = ele.text
end
	
# if we have an image and its not a default avatar then continue
if profile_image and ! profile_image.include? "static.twitter.com"
	begin
		profile_image=profile_image.gsub("_normal","_bigger")
		filename="/tmp/"+rand(100000).to_s+File.extname(profile_image).downcase
		file=open(filename,"w")
		file.write(open(profile_image).read)
		file.close
		# do as you will with the avatar
	rescue
		#fail
	end
else
	#fail
end

Passing a parameter to a before filter

Creating a controller filter that accepts a parameter is less than obvious as I found today while trying to add more than basic authentication to a controller.

Turns out that you need to do it like this :

before_filter :only => [:create, :update, :destroy] do |controller|
controller.filter_function(parameter)
end

rather than allowing a parameters array to pass into the before_filter function which would be nice.