javascript events - Firefox addon: Why the self.port in the panel's contentscript is undefined? -

i meet strange thing firefox addon development:i write code this(i convert commented code chrome extension firefox addon code ):

function sendstoreidentitiesmessage(identities, remember){     console.log("storing identities: "+identities.length);     if(remember==null){         remember=false;     }     //extension.sendmessage({type:"save.identities", identities:identities, remember:remember}, function(response) {     //  identitiesnum=identities.length;     //  identitiesdate=new date();     //  sendgetpageidsmessage(function(){showcodeimagesuccess();});     //});      self.postmessage({type:"save.identities", identities:identities, remember:remember});     self.port.on("response.save.identities",function(response){         identitiesnum=identities.length;         identitiesdate=new date();         sendgetpageidsmessage(function(){showcodeimagesuccess();});     }); } 

when compile addon builder,it gets "error: ns_error_xpc_not_enough_args: not enough arguments [nsidomwindow.postmessage]" error. change code this:

function sendstoreidentitiesmessage(identities, remember){     console.log("storing identities: "+identities.length);     if(remember==null){         remember=false;     }     //extension.sendmessage({type:"save.identities", identities:identities, remember:remember}, function(response) {     //  identitiesnum=identities.length;     //  identitiesdate=new date();     //  sendgetpageidsmessage(function(){showcodeimagesuccess();});     //});      self.port.emit("message",{type:"save.identities", identities:identities, remember:remember});     self.port.on("response.save.identities",function(response){         identitiesnum=identities.length;         identitiesdate=new date();         sendgetpageidsmessage(function(){showcodeimagesuccess();});     }); } 

i got error:typeerror: self.port undefined. so, what's wrong? thanks.

change self addon.detailed document here.