i'm actually just working with datasets saved to the user tag. does that make any difference? no database is being used in this case: no SQL queries, just dataset references.
i know Python fairly well. still my biggest hurdle is being able to 'see' the output. i'm used to dumping contents to the console, seeing what i'm working with, and then setting up the exact functions i'm needing to get the data i want. for example, this script/dataset i'm working with puts square brackets around 2/3rds of the fields and has left most of the keys in the output. i don't know if that's representational or if that's the actual strings held in the dataset.
@jlandwerlen gave me some excellent advice on setting up logging, but that's a trip to the Gateway logging interface every damn time i want something simple. this feels lugubrious at best... and i think @nminchin hit it on the head: "it's always hard work".
as for the toggles themselves, i followed your post and it just generates this error:
Error running action 'component.onRowClick' on ian_development/ian_user_table@D/root/Table:
Traceback (most recent call last): File "<function:runAction>", line 9, in runAction TypeError:
'com.inductiveautomation.ignition.common.BasicDataset' object is unsubscriptable
and the Property Editor pane tells me that 'addtional properties aren't allowed'. 
i am too new to understand what the heck that means. this should be a simple thing. it's a toggle for heaven's sake! how does it not have any useful base functionality? *sigh* whining aside, please help me understand how this should work.