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@scottmatthewman
Created September 20, 2011 15:04
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Validating a URL in Rails 3.1 (and optionally updating it)
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'
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
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