Albatross is a small toolkit for developing highly stateful web applications.
The toolkit has been designed to take a lot of the pain out of constructing intranet applications although you can also use Albatross for deploying publicly accessed web applications.
In slightly more than 3000 lines of Python (according to pycount) you get the following:
* An extensible HTML templating system similar to DTML including tags for: - Conditional processing. - Macro definition and expansion. - Sequence iteration and pagination. - Tree browsing. - Lookup tables to translate Python values to arbitrary template text.
* Application classes which offer the following features: - Optional server side or browser side sessions. - The ability to place Python code for each page in a dynamically loaded module, or to place all page processing code in a single mainline.
* The ability to deploy applications as CGI, FastCGI, mod_python or a pure python HTTP server by changing less than 10 lines of code.
The toolkit application functionality is defined by a collection of fine grained mixin classes. Nine different application types and six different execution contexts are prepackaged, you are able to define your own drop in replacements for any of the mixins to alter any aspect of the toolkit semantics.
Application deployment is controlled by your choice of either cgi, FastCGI, mod_python, or BaseHTTPServer Request class. It should be possible to develop a Request class for Medusa or Twisted to allow applications to be deployed on those platforms with minimal changes.
Albatross comes with over 160 pages of documentation. HTML, PDF and PostScript formatted documentation is available from the toolkit homepage.
The toolkit homepage:
The Albatross mailing list subscription and archives:
CHANGES SINCE 1.1
There have been many improvements and bug fixes since release 1.1. The following page describes the changes in detail.
* A new BranchingSessionContext application context class, that provides better syncronisation between browser state and application state when the application state is stored server-side.
* Improved adapters for the different deployment modes (CGI, FastCGI, mod_python, standalone, etc). Application status codes (such as HTTP_INTERNAL_SERVER_ERROR) are now returned to the browser.
* The page module loader in PageModuleMixin has been reimplemented so that it does not pollute sys.modules. Page modules are now loaded into a synthetic module's namespace, rather than the global module namespace. This will break code that defined classes in page modules and placed instances of those classes into the session.
* Multi-instance response headers are now supported (so, for example, more than one Cookie can be set. The ResponseMixin.get_header() method now returns a list rather than a single string. ctx.req_equals(name) now checks for name.x if name is not found. This makes using image maps as buttons easier.
* Under some circumstances, redirect_url() would redirect to incorrect or invalid URLs (for example, an https app would redirect to http) - the URI parsing has been refactored, and this bug has been fixed. Tests were also added for the refactored URI parsing.
* Several cookie handling bugs were fixed.