OpenHAB - Exec-Binding JSON output

Thing:
Thing exec:command:yourcommand [ command="<YOUR COMMAND> %2$s", interval=0, autorun=false ]

Items:
Switch yourcommand_Run {channel="exec:command:yourcommand:run", autoupdate="false"}
String yourcommand_Out {channel="exec:command:yourcommand:output"}
String valueItem

Rule:
rule "exec json"
when
    Item yourcommand_Out changed
then
    val String json = (yourcommand_Out .state as StringType).toString
    val String value = transform("JSONPATH", "$.tiles[?(@.id =~ /889/)].params.value", json)
    valueItem.postUpdate(value)
end