Chamberlain/LiftMaster MyQ openhab timer rule

garage.rule

import org.openhab.model.script.actions.Timer

var Timer timer = null    

var minutes = 60

rule "Garage Open Timer"
when
    Item GarageDoorString changed    
then
    if(GarageDoorString.state == "Open") {
        logInfo( "garage", "Open. Starting Timer." );
        timer = createTimer(now.plusMinutes(minutes)) [|
            logInfo( "garage", "Timer expired. Closing." );
            sendCommand(GarageDoorSwitch, OFF)
        ]
    } else {
        logInfo( "garage", "!Open." );
        if(timer != null) {
            logInfo( "garage", "Resetting timer." );
            timer.cancel
            timer = null
        }
    } 
end