eZ publish Enterprise Component: Http, Design
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Introduction
============

Purpose of the Http package
---------------------------

A set of classes providing misc HTTP-related functionality, such as
parsing URLs and handling file downloads.

Requirements
============

The component should provide the follwing functionality:

1. Extracting URL parts.
2. Adding previously specified prefix to an URI.
3. Handling of file download by passing the file trough PHP (passthru).

Design
======

The required functionality is split across several independant classes
described below.


ezcHttpUrl
----------

URL handling class. Serves two needs:
- URL parsing. 
- Prepending specified URIs with previously set prefix. 

URL parsing
```````````

Functionality for fetching host, port, uri, script path, 
script name, script parameters, anchor  from the given URL. 

Prepending URI prefix
`````````````````````

It's often needed to have internal links on your pages without 
depending on a specific directory structure. 
For example, you would like to display a link to internal URI '/company/contacts'. 
If your site is located under '/mysite', the link would be '/mysite/company/contants'. 
To not hardcode site directory prefix in all the links, you can set the prefix with 
ezcHttpUrl::addPrefix() and the easily prepend it to any link with ezcHttpUrl::prepend(). 


ezcHttpPassthrough
------------------

Passes specified file through to client browser, genereating the
appropriate HTTP response headers.