Hi,

I'm new to drools, and I made my first steps using the very nice video-tutorial "Build Pong in 13 minutes using JBoss Drools" found here: http://www.youtube.com/watch?v=Omj4PR3v-nI

Eclipse shows building errors, but Pong start anyway. What does this error mean?

in move.drl there is following rule:
<rule "Move Bat Up" timer(expr: bat.speed, bat.speed) no-loop when
    ui : PongUI(  ready == true )
    ( KeyPressed( keyText == "A" ) and bat : Bat( playerId == PlayerId.PlayerOne, y > pconf.padding + pconf.sideLineWidth )
      or
      KeyPressed( keyText == "K" ) and bat : Bat( playerId == PlayerId.PlayerTwo, y > pconf.padding + pconf.sideLineWidth ) )
    td : TableDirty( )      
then    
    tableG = ui.getTablePanel().getTableG();
    tableG.setColor( Color.BLACK ); // background
    tableG.fillRect( bat.x, bat.y, bat.width, bat.height );
     
    modify( bat ) { y = bat.y - 2 };
    tableG.setColor( Color.WHITE ); // background
    tableG.fillRect( bat.x, bat.y, bat.width, bat.height );  
    modify( td ) { dirty = true };
end

the error message is:
[Error: unable to resolve method using strict-mode: org.drools.spi.KnowledgeHelper.td()]
[Near : {... @Modify with( td ) { dirty = true }; ....}]


in another File (ui.drl) TableDirty is defined:

declare TableDirty
@propertyReactive
    dirty : boolean
end



Any ideas what this error message means? And why can I start pong despite this error?

Thanks a lot for helping me

Stefan