Overview
Just another article of the URL shortening services series.
Today, we are going to talk
about another hot and easy-to-use service, it's Tweetburner. If you haven't used
it before, then it's the time to.
We're going to discuss how
to use Tweetburner first. After that, we'll inspect its API and learn how to use
it in your .NET application.
Introduction
Again, one of the most popular URL shortening services ever.
Today is dedicated for
Tweetburner (known as
twurl,) one of the hot, simple, and easy-to-use shortening
services that you can compare to
is.gd.
Description
When you visit Tweetburner
website (via http://tweetburner.com or
http://twurl.nl,) you can see that it allows
users to register to gain more functionalities (specifically, link analytics.)
However, at the time of this writing, the account page is disabled for technical
issues and nothing interesting would happen if you register there.
One of the hot features of
Tweetburner is that it allows you to post your links to
twitter (you guessed)
and friendfeed as
soon as they're shortened just click 'Share this link' before you leave the
page.
Unfortunately, you can't benefit from this sharing feature
programmatically, but of course, you can create your own routines.
After shrinking your URL,
you get a new short link about 22 characters long (18 in is.gd) prefixed with
http://twurl.nl.
API
Actually, Tweetburner
doesn't help you with an API.
Instead, it provides you with a simple web page (used for shortening URLs) that
you can access it from your code and get your short URLs.
Let's try it! Browse to our
key page, http://tweetburner.com/links,
and push your long URL and click the shortening button.
[caption id="attachment_2805" align="alignnone" width="500"
caption="Figure 3 - Shortening Links API, Tweetburner"]
[/caption]
So how you can access this
page via your .NET application and fill in its single field? Let's get the idea!
If you check the API documentation page,
you might find that you are required just to request information from
that page, post it the required URL via a simple string included in the
request body, link[url]={0} (where {0} is the long URL, and
just wait for the response that would contain the short URL of course if the
function succeed.
Do you find that 'link[url]={0}'
strange? Try this with me! Browse to our page,
http://tweetburner.com/links, and
save it as HTML in your PC (not required, just grab its HTML code.)
Sure we are interested on
this magical text box, so scroll down to its definition that looks like this:
<input
id="link_url"
name="link[url]"
size="30"
type="text"
/>
Notice that the text
box is given the name 'link[url]', that's why we push 'link[url]={0}' on the
request body. Given that hot information, you can push any data to any web form,
just get the information required.
Now, let's code! The next
function browses to our page,
http://tweetburner.com/links, pushes the long URL specified, and gets the
short URL back from the server. (Remember to include the namespace System.Net
for the code to work properly.)
VB.NET
Function Shorten(ByVal
url As String)
As String
url = Uri.EscapeUriString(url)
Dim req As
HttpWebRequest = _
CType(WebRequest.Create("http://tweetburner.com/links"),
HttpWebRequest)
req.Timeout = 5000
req.Method = "POST"
req.ContentType =
"application/x-www-form-urlencoded"
Dim buffer() As
Byte = _
System.Text.Encoding.UTF8.GetBytes("link[url]="
+ url)
req.ContentLength = buffer.Length
Dim ios As
System.IO.Stream = req.GetRequestStream()
ios.Write(buffer, 0, buffer.Length)
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
Notice that we have specified the POST
method because it's required if you are going to change some data in the server.
It's worth mentioning too that we have set the content type to
application/x-www-form-urlencoded because it's required if you are
going to push data to a web form (it's usually perfect for all web forms except
file-uploads.)
In addition, we have
included the input required in the request stream.
What's next
Some other articles about
URL shortening services are available
here.