Overview
This is another article 
that talks about URL shortening services. Today we are going to talk about Cligs, 
one of the popular shortening services on the web.
Be prepared! 
Introduction
![cligs]()
Today we are talking about another popular shortening service; it's
Cligs, one of the most popular 
shortening services that provide lots of premium features for FREE.
Enough talking, let's begin 
the discussion.
	In December 2009, Cligs 
	acquired by Mister Wong (a very 
	nice bookmarking service.)
Description
How Cligs can help you? 
Cligs gives you plenty of features, including the following:
	- Shortening URLs (registered and non-registered 
	users): You get a short URL that's no more than 20 characters (Tweetburner 
	is 22 and
	
	is.gd is only 18) including the domain
	http://cli.gs.
 
	- URL Management (registered users only): It allows 
	you to manage your short URLs, to edit them, and to remove them if you like.
 
	- Real-time Analytics (registered users only): How 
	many clicked your link, and when.
 
	- URL Previewing 
	(registered and non-registered users): Preview the URL before opening it. 
	Protects you from spam and unwanted sites.
 
API
Cligs provides you a very 
nice API with 
many advantages. The first advantage that we want to talk about is its 
simplicity. The API is very simple; it has just two functions, one for 
shortening URLs, and the other for expanding short URLs (to expand a 
URL means to get the long URL from the short one.)
Another advantage of this 
API is that it allows you to shorten the URLs whether you are a registered user 
or not. Of course a registered user need to get an API key in order to link the 
API calls to his accounts so he can manage the links generated by the API and to 
watch the analytics.
Shortening URLs
The first function is used 
for shortening URLs and it's called, create. This function has the 
following address:
http://cli.gs/api/v1/cligs/create?url={1}&title={2}&key={3}&appid={4}
The API is still in version 
1, that's why you see 'v1' in the address. This function takes four parameters, 
only the first one is required, other parameters are used for authentication:
	- Url: Required. The URL to be shortened.
  
	- Title: Optional. For authenticated calls 
	only. The name that would be displayed on the short URL in your control 
	panel (used for managing your URLs.)
  
	- key: Optional. If you are a registered user 
	and you want to link the API calls to your account, you'll need to enter 
	your API key here.
  
	- Appid: Optional. If you have used an API 
	key, then you have to provide your application name that used to generate 
	this API call (help users know the source of the link.)
 
So how can you use this 
function? If this is an anonymous call (i.e. no authentication details 
provided,) just call the function providing the long URL in its single required 
argument.
If you need to link this 
call to a specific account, then you'll need an API key, which the user can get 
by signing in to his Cligs account, choosing 'My API Keys', then clicking 
'Create New API Key' (if he doesn't have one you.) The last step generates an 
API key that's no exactly 32 characters (see figure 1.)
![Cligs - API Keys Figure 1 - Creating API Keys, Cligs]()
After you get the API key, 
you can push it to the function along with your application name in the 
appid argument.
What about the title 
argument? For registered users, they can access their clig list (see 
figure 2) and see the URLs they shortened and the titles they choose above each 
of the URLs.
![Cligs - My Cligs]()
	
	Now, let's code! The following function makes use of the Cligs API to 
	shorten URLs. It accepts three arguments, the long URL, the API key, and the 
	application name. If the API key is null (Nothing in 
	VB.NET,) the call is made anonymously, otherwise, the API key and the 
	application name are used.
	
	// C#
	string 
	Shorten(string 
	url, string 
	key, string 
	app)
	{
	    url = Uri.EscapeUriString(url);
	    string 
	reqUri =
	        String.Format(@"http://cli.gs/api/v1/cligs/create?url={0}", 
	url);
	    if 
	(key != null)
	        reqUri += 
	"&key=" 
	+ key + "&appid=" 
	+ app;
	
	    
	HttpWebRequest req = (HttpWebRequest)WebRequest.Create(reqUri);
	    req.Timeout = 5000;
	
	    
	try
	   
	{
	        using 
	(System.IO.StreamReader reader =
	            new 
	System.IO.StreamReader(req.GetResponse().GetResponseStream()))
	        {
	            return 
	reader.ReadLine();
	        }
	    }
	    catch 
	(WebException ex)
	    {
	        return 
	ex.Message;
	    }
	}
	' VB.NET
Function Shorten(ByVal url As String, ByVal key As String, ByVal app As String) As String
    url = Uri.EscapeUriString(url)
    Dim reqUri As String = String.Format("http://cli.gs/api/v1/cligs/create?url={0}", url)
    If key Is Nothing Then
        reqUri &= "&key=" & key & "&appid=" & app
    End If
 
    Dim req As WebRequest = WebRequest.Create(reqUri)
    req.Timeout = 5000
 
    Try
        Dim reader As System.IO.StreamReader = New System.IO.StreamReader(req.GetResponse().GetResponseStream())
 
        Dim retValue As String = reader.ReadLine()
        reader.Close()
 
        Return retValue
    Catch ex As WebException
        Return ex.Message
    End Try
End Function
Expanding 
	URLs
	The other function we 
	have today is the expand function that's used to get the long URL 
	from the short one (e.g. to expand the short URL
	http://cli.gs/p1hUnW to be
	http://JustLikeAMagic.com.) This 
	function is very simple and it has the following address:
	http://cli.gs/api/v1/cligs/expand?clig={1}
	This function accepts 
	only a single argument, that's the clig (short URL) to be expanded. 
	The clig can be specified using one of three ways:
			- The clig ID. e.g. p1hUnW.
 
		- The raw URL. e.g.
		http://cli.gs/p1hUnW.
 
		- The encoded URL. e.g. 
		http%3A%2F%2Fcli.gs%2Fp1hUnW.
 
	
	
		You can read more about URL encoding
		
		here.
	Now it's the time for 
	code! The following function takes a clig and returns its original URL:
	
	// C#
	HTML clipboarstring Expand(string url)
{
    url = Uri.EscapeUriString(url);
    string reqUri = String.Format(@"http://cli.gs/api/v1/cligs/expand?clig={0}", url);
 
    HttpWebRequest req = (HttpWebRequest)WebRequest.Create(reqUri);
    req.Timeout = 5000;
 
    try
    {
        using (System.IO.StreamReader reader =
            new System.IO.StreamReader(req.GetResponse().GetResponseStream()))
        {
            return reader.ReadLine();
        }
    }
    catch (WebException ex)
    {
        return ex.Message;
    }
}' VB.NET
	
Function Expand(ByVal url As String) As String
    url = Uri.EscapeUriString(url)
    Dim reqUri As String = String.Format("http://cli.gs/api/v1/cligs/expand?clig={0}", url)
    Dim req As WebRequest = WebRequest.Create(reqUri)
    req.Timeout = 5000
    Try
        Dim reader As System.IO.StreamReader =New System.IO.StreamReader(req.GetResponse().GetResponseStream())
        Dim retValue As String = reader.ReadLine()
        reader.Close()
        Return retValue
    Catch ex As WebException
        Return ex.Message
    End Try
End Function
Where to go next
	Some other articles 
	about URL shortening services are available
	
	here.