README
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ShortURL - an application to shorten URLs
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Requirements:
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The application shall shorten URLs for logged in users.
Therefore we need a storage for users. Users can log in via 
OpenID/OAuth, so we need no password storage.

After logging in, the user can see an overview of her URLs 
shortened so far. Also she has the possibility to enter a
new URL into a field that will then be shortened. 

The user at first becomes a generated URL that can then be adapted. The URL
will be stored after actively hitting a button or so.

Shortys (shortened URLs) can be altered afterwards by creating a link to the 
original one.

Shortys consist automaticaly of 6 to 8 characters including upper- and
lowercase Characters as well as the digits 0 through 9. therefore we have
62^8 possible URLs which is something about 218.340.105.584.896. That should
suffice for the moment. That makes a total of 20-22 characters for a short
URL like http://hei.gl/8chaRacs

When a short URL is called the browser is sent a 302-redirect header to the 
original URL.

When doing so, some informations are stored about the requesting user. These
include the following:

* IP-Adress (anonymized to the first two triplets for IPv4)
* User-Agent
* Referer (if there has been one)
* Prefered Language

From the IP-Adress we can retrieve the country from where the visit came,
from the user-agent we can retrieve the Users Operating System, the kind of
browser used to view the url and the version of the browser.
From the Referer we can see which pages have linked the shortUrl and from
the prefered language we can see which language the user preferes.

The application also has an API that allows users to interact via JSON, XM-RPC, 
SOAP or a REST-full interface with the shortener.

The user can klick onto one of her links to see some additional informations
about the usage of her shortURLs. The informations can be retrieved by adding
an '=' to the end of the shortURL.

Multiple Users can share a single account by adding users to an accout. So 
one user creates an account and her OpenID is added to that account. That
user can then add/remove other users to her account.

A logged in user can then select which account she now wants to use

Shortys have to be at least 6 characters long, everything below that has 
administrative purposes (i.E. to identify the API to be used)

Technical
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  User-Table 
  	holds id, name, openID, mail?, active
  Account-Table 
  	holds id, account-name, active
  User-Account-Relation 
  	holds user-id, account-id, admin-flag
  URL-Table
  	holds id, account-id, URL, short-URL, DateTime
  Visit-Table
  	holds id, url-id, IP-Address, Referer, User-Agent, Prefered Language, DateTime