So I have a BarcodeScannerInput field in Perspective. it gets some data similar to this ["testValue1", "testValue2", "testValue3"] I then also have an expression where I want to fetch the very last (most recent) element. {../BarcodeScannerInput.props.data}[0] This works to get the first element ho…

Expression language does not allow the use of -1 like python for collection item access, you'll have to use something like {path.to.collection}[len({path.to.collection})-1]

This is what I ended up using! Is there any where to make suggestions for expression language to support -1 indexing? I think it would be a very nice language especially since Ignition also uses Python for scripting

If you are using my Integration Toolkit (and why wouldn't you?), you can use its relatively new qvAt() function to get negative index support. [image] Automation Professionals' Integration Toolkit Module 3rd Party Modules That was easy. grin Automation Professionals is p…

As mentioned in Phil's linked thread, we already have a plan to add negative indexing to known-to-be-ordered collection types. No timeline on implementation, though.

Select last value from collection

Ignition

pturmel April 29, 2025, 8:21pm 4

If you are using my Integration Toolkit (and why wouldn't you?), you can use its relatively new qvAt() function to get negative index support.