DisplayMode.Disabled object does not execute OnChange? Options?

[Sorweel]

I'm making a more refined excel-like experience for my app.  I'm displaying and modifying a dataset in a grid using label objects.  Some columns are calculated from others and so I don't want users modifying them so I set DisplayMode.Disabled on those label objects.  Some columns users can directly input data affecting those other calculations, those are left enabled.  My problem is the Disabled labels do not allow the Onchange function to fire, creating an unnecessary headache in development.

My example:

I have a row of data with columns:  A - B - C - D - E - F - G

Red items are calculated and their label is set to Disabled.  User's want to see those calcs so they need to remain visible.  Blue/underlined items users can control the input directly.

A*B=C

C*D=E

E*F=G

In a smart app, I'd use labels A and B's OnChange function to modify C.  Then C and D's OnChange to modify E.  E and F's OnChange to modify G.  Except I can't use OnChange for C or E because they are disabled....even though I am changing the values in the label and on the base dataset, they don't initiate an OnChange event...

So now I need to set A and B' OnChange to modify all downstream calculations for C, E and G using D and F.  Then D's Onchange to grab A, and B so I can modify E and G.  F's OnChange to use A, B, and D to modify G.  Doing it this way is so much extra overlap.

Perhaps not a huge problem at this level, but say I want any change to G to trigger another calculation update elsewhere in the app.  Guess where that logic goes?  I have to go all the way back to A, B, D, and F and add that same functionality copied to 4 items, rather than simply having OnChange G trigger an update.

If I need to make a change to the calculations, I have to track down the whole schematic back to the base inputs and maintain parity across all related items.  I can change the whole row at once, but my use-case is more complicated than the above example where I'd want a change on certain columns to fire an update elsewhere in the app.  I'd like to keep this rationale of a series of a events that can be affected at any point along the series rather than an everything-at-once-approach.

Am I approaching this the wrong way?  Can I set up a series of event triggers that can be initiated from different places?  OnChange seemed to be the proper way to me until Disabled objects got in the mix.  Is there a use case for having the Disabled object disregard the OnChange function or can we simply ask Microsoft to enable OnChange to fire for disabled objects?

[Pstork1]

Try using DisplayMode.View instead of DisplayMode.Disabled.  Also, are you using TextInputs rather than Labels? Labels don't have an OnChange property and the OnChange event in a TextInput control requires that it be selected first.  So I don't think there is any way to do what you want.

[Sorweel]

DisplayMode.View does not update OnChange either from my testing.

You are correct, TextInputs.  

[Pstork1 · Accepted solution]

As I mentioned, OnChange only fires after the control has been selected and you leave the control to focus on another control. So I don't think you have any choice other than putting the logic in the OnChange of one of the controls being updated by the user.  But for example, you could easily have the OnChange from D set a variable used as the default for E and make use of the value from C.

Or just put the formula in the default property of E directly.  Then if the value for C or D change E will update.

[Sorweel]

I see.  The problem is the OnChange is really a user interaction event and not a data change event.  That helps me understand it better.  I think the answer is to continue to struggle through and instead of an order of events, update a data table with all related data located within the same row and changed in entirety whenever a change is acted at any step in series.

I appreciate the insight!