[Rules DSL] Get item from string name!

Tutorials & Examples
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21

I’m curious to see an example where other means could not be used to ensure that the Item exists. Using the ItemRegistry may be the easiest, but it comes with a performance hit, so it would be best to find another way. That said, there are other useful ItemRegistry methods. In Jython, I use this to check for the existence of an Item…

if ir.getItems("Current_Timestamp") == []:

This is not used in a rule, but in a script that is creating Items if they do not already exist. This uses ItemRegistry.getItems() (note the ‘s’), which returns a collection of Items matching a regex. The regex being a literal string. The same could be done in a DSL rule using…

if (ScriptServiceUtil.getItemRegistry.getItems("item_name_to_check_for_existence") == newArrayList) {

This could potentially be used as another workaround for checking existence of an Item given an Item name as a string. For example…

val test = ScriptServiceUtil.getItemRegistry.getItems("bad_item_name")
if (test == newArrayList) {
    logInfo("Rules", "Bad item")
} else {
    logInfo("Rules", "Test [{}]", test.get(0).name)
    test.get(0).sendCommand(ON)
}
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