Mozilla hacking While learning about XPCOM, I took a deeper look at mozilla itself and I decided to finally fix the itches I have.  I use mozilla as  browser,mail reader and calendar  ( when I don't use pine, konqueror and korganizer ). On top of my list of things I don't like is the weird "mork" database used to store the addressbook. I wouldn't mind it if it would allow export to vcard/ics - which can be read and is used as primary file format by all other addressbook applications. So I'm trying to write a small extension to export the ab, and maybe synchronize it with other apps ( Multisync does a great job already for evolution, zaurus, ce, and many other apps ).

I think I found the magic incantation to get the addressbook, in the mess of badly documented objects and components:

    const abURI = "moz-abmdbdirectory://abook.mab";

    var rdf=Components.classes["@mozilla.org/rdf/rdf-service;1"].getService(Components.interfaces.nsIRDFService);

<>    var directory = rdf.GetResource(abURI).QueryInterface(Components.interfaces.nsIAbDirectory);
    var childE=directory.childCards;
    
    try {
        childE.first();
        var card;
        while( 1 ) {
            card=childE.currentItem().QueryInterface( Components.interfaces.nsIAbCard );
            processCard( card );
            childE.next();
        }
    } catch( ex ) {
        // nothing - it's how enumerations end... Weird xpcom/js - isDone is also throwing exception.
    }

The enumeration is very weird - at least for a java programmer not used with flow-control-by-exceptions. 

Few other things I discovered:

• Ignore the books/tutorial and anything that talks about how to use DTD for internationalization and all the super-complex layouts.
  
• Hacking mozilla extensions can be actually fun and easy if you find the simple way to do it, just like in java ( and just like in java, a lot of mozilla developers love unnecessary complexity )
  
• All interesting things happen in the chrome directory, after you register your stuff in the installed-chrome.txt-  the scripts won't be executed otherwise.
• You do need contents.rdf ( their manifest ), the contents directory, a xul and a js. So far this is the minimum - pretty reasonable.
  
• XPI ( installer ) is indeed very easy. Uninstalling is a different story.
  

Posted by costin at April 02, 2004 09:11 AM