A few old friends and I often hang together on our usual IRC channel, and while discussing we like to share links. I thought it might be a good idea to use a web tool for that so that we can also share our favorite links with the rest of the world. I thought a private Digg clone could play that role, and I needed an excuse for more PHP development. After some research I found that Pligg was the best candidate. I downloaded Beta 9.7 and I have been quite amazed how fast I got a smooth Pligg site up and running – it seems like much work went into this code.

The first bug that arose was mangled accents in some URLs. I solved it by adding a few cases to a character substitution matrix. This matrix is used to sanitize strings before using them for URLs. The problem is that this method requires each accented character to be treated individually. Maybe a more general solution exists. Anyway I am surprised that no other user noticed that problem with French accents before.

Since I wanted to use Pligg in a way closely associated with our IRC habit, I thought it might be a good idea to make Pligg capable of notifying an IRC channel of an upcoming story. Rumaging through PHP libraries capable of speaking IRC I ended up using Net_SmartIRC which is available in Debian as php-net-smartirc. The examples packaged with the class are quite good at teaching its use so I soon wrote a small proof-of-concept of notifying an IRC channel from PHP.

Some more hacking later I figured how to splice that IRC notification functionality into Pligg. This is a prototype : it works fine for me but you need to overwrite a file from the standard Pligg and edit it with your parameters, and it probably ignores any convention used by those who are familiar with working on Pligg. To reach release quality this functionality should probably be architectured as a proper configurable Pligg plugin. To use it, you need to install Net_SmartIRC which is available in Debian as php-net-smartirc. Make sure that the path of that library as declared in my submit.php is correct.Then you need to edit my submit.php to set connect parameters, login parameters, and the channel. Make a backup of your original submit.php and replace it with mine. That is all !

With IRC notification in place I found that I did not want just anyone spamming our favorite IRC channel. Pligg has three hardcoded user levels : “user”, “admin” and “god”. By default the users can submit posts. I decided to restrict posting to the “admin” and “god” levels. That way we keep control of posting, our friends can vote and comment as “user” and the rest of the anonymous world can read the site.

With the beginning of a familiarity with the Pligg code it did not take me too much grepping to understand the conditional access system and wedge a typical implementation where it should work. And work it did, just as advertised ! I am not sure that the core Pligg developers intended this previously clean switch statement to be hacked like that, but it works for me. A further step would be to make this restriction code conditional and to make the condition a user-configurable parameter in /admin_config.php so that god can choose at which user level submissions are allowed. I am sure that many site operators would appreciate this feature.

So as a summary and conclusion, here is the patch that modifies Pligg’s 9.7 submit.php to provide post submission restriction by user level and IRC notification of posts :

Have fun with Pligg ! I’m done with it for now but who knows what other functions I’ll feel like hacking into it in the future…