type MollomState = ReaderT MollomConfiguration (StateT MollomServerList IO)
type MollomMonad = ErrorT MollomError (StateT (Maybe SessionID) MollomState)


The main concept of the code remains the same, each exported function calls the service function. The latter returns a MollomState a, to capture the fact that during the Mollom request, we potentially need to update the list of servers we can query with API calls. This result is then lifted into the MollomMonad stack by using the following function.


returnStateT a = StateT $ \s -> liftM (flip (,) s) a


This is illustrated in the following control flow figure (for a full sized image, follow the link to flickr):

The error handling is done by usage of the ErrorT monad transformer, which add the possibility to return a Left MollomError as function value, indicating a fault during the handling of the request. At this point, I have not added a decent runMollomMonad function, as I am still pondering which functions may be most useful for the users of this library. However, you can easily employ the following function, where defaultMollomConfiguration :: MollomConfiguration and we start without any servers that are available.


(\m -> (runStateT $ (runReaderT $ (runStateT . runErrorT $ m) (Nothing) ) defaultMollomConfig) UninitialisedServerList)


As usual, the code is available from both the GitHub repository, as well as from Hackage. All feedback is welcome. Thanks to #haskell and #ghentfpg for bearing with my questions.

Given that I enjoy programming in Haskell and need to sharpen my Haskell-fu, I set out to write a library for interfacing with the Mollom API. The library is far from finished, but it is functional at this point, so if you have Mollom keys, you can call the services and fight the spam war on your Haskell driven website.

I maintain two repositories where you can get the library:

• At Hackage: hMollom
• At github: hMollom.git

At this point the library has been given version 0.1. So it is still lacking quite a lot of features. Stuff that is on the immediate TODO list:

• Add fault handling
• Add server list refreshing
• Encapsulate the state in a monad

Any feedback is appreciated.

That said, first thing to do is check Hackage and find stuff we can reuse. haxr immediately comes to mind for the XMLRPC stuff. Other packages I am using are base64-string, crypto, configfile,
Installing the above will download and install a number of other libraries on which these depend. Still, Hackage seems to do the trick just fine, installing everything I needed.

You can find the tarball containing the modules and the darcs repository here. To pull from the darcs repository, use darcs get http://itkovian.net/darcs/python_mollom.

You can get the code from the darcs repository at http://itkovian.net/darcs/python_mollom. Alternatively, a packed tarball is also available.

For the moment, the repository contains two files Mollom.py and HTTPTransport.py. The former contains the MollomAPI and MollomFault classes. The latter contains a derived class to deal with HTTP transport in the XML PRC library, as the default Python code does not seem to do things correctly. To get the response from the Mollom service as a Python dictionary, you need to either use the provided HTTPTransport class or provide your own implementation

To deal with caching and using session IDs a MollomBase class is present, which can be overridden to allow a user defined caching mechanism for the server list to be used. This class is still under heavy development, so it is prone to (frequent) changes.

MollomAPI offers the following methods:

• getServerList
• checkContent
• sendFeedback
• getImageCaptcha
• getAudioCaptcha
• checkCaptcha
• getStatistics
• verifyKey

I plan to see if I can get this into Django as well as a contributed app that can be included in a Django project.

Update (2008/09/18) I have incorporated the changes made to the API document on 2008/09/10. The version of the tarball has been bumped to 0.2. Additionally some bugs were fixed, so you might want to update to this version rather than sticking with the old one.

Update (2010/02/08) I have moved the code to a new repository at GitHub. Get the library using git clone git://github.com/itkovian/PyMollom.git. For now, I do plan on keeping the darcs repo hosted at my website and the github repo in sync, so you can pull from either.

Luckily, in the past, I have shared an office with Dries who has been thinking hard on the spam problem and has been working on a solution since he completed his PhD. The goal was to provide not simply spam protection, but also to help people increase the quality of the content, by protecting against profanities, anonymous user registration etc. To shorten a long story, this website has been using Mollom as its spam protection mechanism since its inception. As you can see, Mollom has been quite effective, I’ve only had five (iirc) false negatives (spam that was classified as acceptable content), which is almost perfect.

Thanks guys, you rock!