| Class | ShortURL |
| In: |
lib/shorturl.rb
|
| Parent: | Object |
Main method of ShortURL, its usage is quite simple, just give a url to shorten and an optional service. If no service is selected, RubyURL.com will be used. An invalid service symbol will raise an ArgumentError exception
Valid service values:
| :rubyurl: | uses RubyURL.com |
| :tinyurl: | uses TinyURL.com |
call-seq:
ShortURL.shorten("http://mypage.com") => Uses RubyURL
ShortURL.shorten("http://mypage.com", :tinyurl)
# File lib/shorturl.rb, line 26
26: def self.shorten(url, service = :rubyurl)
27: case service
28: when :rubyurl then rubyurl(url)
29: when :tinyurl then tinyurl(url)
30: when :shorl then shorl(url)
31: when :snipurl then snipurl(url)
32: when :metamark then metamark(url)
33: else raise ArgumentError, "Invalid service"
34: end
35: end
Abstract method to shorten a URL. Respects the DRY principle. In case of a network-related exception, return nil.
Parameters:
hostname: hostname of the service code: expected return code (200, 302, etc.) Converted to a string action: string representing the action to be executed on the HTTP object with +instance_eval+ block: block of code which scrapes the HTML and returns the shortened URL. Takes one parameter.
# File lib/shorturl.rb, line 45
45: def self.get_short_url(hostname, code, action, &block) # :yields: html_body
46: begin
47: Net::HTTP.start(hostname, 80) { |http|
48: response = http.instance_eval(action)
49:
50: if response.code == code.to_s
51: block.call(response.read_body)
52: end
53: }
54: rescue SocketError, Net::HTTPExceptions => e
55: return nil
56: end
57: end
Shorten a URL with metamark.com. Same technique as TinyURL
# File lib/shorturl.rb, line 107
107: def self.metamark(url)
108: get_short_url("metamark.net", 200,
109: "post('/add', 'long_url=#{url}')") { |body|
110: line = body.split("\n").find { |l| l =~ /xrl\.us/ }
111: short_url = URI.extract(line)[0]
112: return short_url
113: }
114: end
Shortens an URL with RubyURL.com. Since RubyURL uses a redirection (code 302), instead of using HTTP#post, we send our data directly to the create action. The response is a small HTML line which contains our shortened URL plus /rubyurl/show, so we manually remove that with gsub.
# File lib/shorturl.rb, line 65
65: def self.rubyurl(url)
66: get_short_url("rubyurl.com", 302,
67: "get('/rubyurl/create?rubyurl[website_url]=#{CGI.escape(url)}')") { |body|
68: short_url = URI.extract(body)[0].gsub("rubyurl/show/", "")
69: return short_url
70: }
71: end
Shorten a URL through with shorl.com. Same technique as TinyURL
# File lib/shorturl.rb, line 88
88: def self.shorl(url)
89: get_short_url("shorl.com", 200,
90: "post('/create.php', 'url=#{url}')") { |body|
91: short_url = URI.extract(body)[2]
92: return short_url
93: }
94: end
Shorten a URL with snipurl.com. Same technique as TinyURL
# File lib/shorturl.rb, line 97
97: def self.snipurl(url)
98: get_short_url("snipurl.com", 200,
99: "post('/index.php', 'link=#{url}')") { |body|
100: line = body.split("\n").grep(/txt/)[0]
101: short_url = URI.extract(line)[1][0..-2] # Remove trailing '
102: return short_url
103: }
104: end
Shortens an URL with TinyURL.com. We post a request to the create.php action with our URL as a parameter. We then read the HTML code, split it into an array, find an element that contains our shortened URL and extract it.
# File lib/shorturl.rb, line 78
78: def self.tinyurl(url)
79: get_short_url("tinyurl.com", 200,
80: "post('/create.php', 'url=#{url}')") { |body|
81: line = body.split("\n").find { |l| l =~ /hidden name=tinyurl/ }
82: short_url = URI.extract(line)[0]
83: return short_url
84: }
85: end