How to debug a chart expression in general?

[RickyLam]

Dear all,

I am a newbie in Qlik Sense. I am currently being asked to help check the expressions in various visualisations of a Qlik Sense app that is developed by someone who is no longer with us. Many of these _chart_ expressions are so complicated that when they go wrong, I really have hard time to troubleshoot them. Does Qlik Sense provide some debugging features, like trace, etc to help ease the pain of troubleshooting? 

Specifically, I found the following chart expression doesn't work:

Sum(Round(IF(SelectedChoice='Avg Amount', AmountLineTotal, QtyLineTotal)

/

IF(InMonth([OrderDate], Today(0), 0), 100, 1000), 0.01))

The above expression does not work in the sense that the actual denominator based on the computed figure of the chart is neither 100 nor 100 of a given dimension..... Please advise,

[marcus_sommer]

I think the approach itself isn't expedient - means creating a complex logic and if it don't returned the expected results to get into a debugging-mode. IMO better is the reversed way of developing the logic step by step by using an extra expression for each calculation-part - the sum(), the multiple if-loops, ... - within a table-chart against the needed dimensions and maybe also some others (higher groupings, more granular ones, ...). The parts which work could then be combined and be checked again.