@assigned が常に 0 なのはなぜですか?
var gates:XML = <gates>
<gate_id>
10991
</gate_id>
<gate_id>
10999
</gate_id>
<gate_id>
11000
</gate_id>
<gate_id>
11001
</gate_id>
</gates>;
var assignedGateIds:Array = ["10991","10999"];
for each(var xgate:XML in gates..gate_id){
var gateId:String = xgate.text();
if(assignedGateIds.indexOf(xgate.text())>-1){
xgate.@assigned = 1;
}else{
xgate.@assigned = 0;
}
}