From e274bb1757aa3c27645c181bae6164131a7a35dd Mon Sep 17 00:00:00 2001
From: Jeff Shumate <jeff@catapulsion.net>
Date: Wed, 25 Jan 2012 22:27:46 -0700
Subject: add source url for post

---
 config/initializers/url_validator.rb | 85 ++++++++++++++++++++++++++++++++++++
 1 file changed, 85 insertions(+)
 create mode 100644 config/initializers/url_validator.rb

(limited to 'config/initializers')

diff --git a/config/initializers/url_validator.rb b/config/initializers/url_validator.rb
new file mode 100644
index 0000000..15635e0
--- /dev/null
+++ b/config/initializers/url_validator.rb
@@ -0,0 +1,85 @@
+require 'net/http'
+
+class UrlValidator < ActiveModel::EachValidator
+
+  def validate_each(record, attribute, value)
+    url = value
+    
+    # Regex code by 'Arsenic' from http://snippets.dzone.com/posts/show/3654
+    if url =~ /^
+( (https?):\/\/ )?
+( [a-z\d]+([\-\.][a-z\d]+)*\.[a-z]{2,6} )
+(
+(:
+( \d{1,5} )
+)?
+( \/.* )?
+)?
+$/ix
+      url = "http#{'s' if $7 == '81'}://#{url}" unless $1
+    else
+      record.errors[attribute] << 'Not a valid URL'
+    end
+
+    if options[:verify]
+      begin
+        url_response = RedirectFollower.new(url).resolve
+        url = url_response.url if options[:verify] == [:resolve_redirects]
+      rescue RedirectFollower::TooManyRedirects
+        record.errors[attribute] << 'URL is redirecting too many times'
+      rescue
+        record.errors[attribute] << 'could not be resolved'
+      end
+    end
+
+    if options[:update]
+      value.replace url
+    end
+  end
+end
+
+# Code below written by John Nunemaker
+# See blog post at http://railstips.org/blog/archives/2009/03/04/following-redirects-with-nethttp/
+class RedirectFollower
+  class TooManyRedirects < StandardError; end
+
+  attr_accessor :url, :body, :redirect_limit, :response
+
+  def initialize(url, limit=5)
+    @url, @redirect_limit = url, limit
+    logger.level = Logger::INFO
+  end
+
+  def logger
+    @logger ||= Logger.new(STDOUT)
+  end
+
+  def resolve
+    raise TooManyRedirects if redirect_limit < 0
+
+    self.response = Net::HTTP.get_response(URI.parse(url))
+
+    logger.info "redirect limit: #{redirect_limit}"
+    logger.info "response code: #{response.code}"
+    logger.debug "response body: #{response.body}"
+
+    if response.kind_of?(Net::HTTPRedirection)
+      self.url = redirect_url
+      self.redirect_limit -= 1
+
+      logger.info "redirect found, headed to #{url}"
+      resolve
+    end
+
+    self.body = response.body
+    self
+  end
+
+  def redirect_url
+    if response['location'].nil?
+      response.body.match(/<a href=\"([^>]+)\">/i)[1]
+    else
+      response['location']
+    end
+  end
+end
\ No newline at end of file
-- 
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