Adding and delete a row of data to the Polygrid

Paul Dupuis paul at
Sun Aug 27 15:43:27 EDT 2023

I ran into an inconsistency with the Polygrid

The Polygrid property pgDataOfRow returns the data for the row indicated 
by what pgInternalPointer is set to. The pgData of the Polygrid is a 2D 
array of the form array[n][columnName]value and pgDataOfRow returns a 1D 
array of the form array[columnName]value.

Now the properties "AddDataAfter" (or "AddDataBefore") to add a row of 
data to the Polygrid After )or Before) the row pointed to by 
pgInternalPointer expects a 2D array of the same form as pgData or 

So, consider the follow use case where you want to remove a row of data 
(the last row of a table) that displays subtotals for each column but 
then later (upon some user action or whatever) you want to add it back

       put the numberOfRows      of widget "rwTableview" into N
       set the pgInternalPointer of widget "rwTableview" to N
       put the pgDataOfRow       of widget "rwTableview" into 
sColSubtotalArray -- save the subtotal row in the form 
sColSubtotalArray[columnName]value, a 1D array
       set the pgDeleteRow       of widget "rwTableview" to N -- delete 
the subtotal row

And now you want to add it back
       put the numberOfRows      of widget "rwTableview" into N
       set the pgInternalPointer of widget "rwTableview" to N
       set the addDataAfter      of widget "rwTableview" to 

That LAST line (addDataAfter) will fail since the array saved by the 
pgDataOfRow is a 1D array and addDataAfter expects a 2D array. If could 
a simple repeat look through the keys of sColSubtotalArry will let you 
build a new 2D array with 1 row and the columns being the keys or column 
names, so it is not hard to convert, but SHOULD YOU HAVE TO?

You can convert with
       put the number lines of the keys of sColSubtotalArray into N
       repeat for each key tKey in sColSubtotalArray
         put sColSubtotalArray[tKey] into tA[1][tKey]
       end repeat
      -- tA is now in the format that the addDataAfter property of the 
Polygrid requires.

I am not sure this is a BUG. It is certainly an inconsistency and 
changing it would break some current code. On the other hand, the 
Polygrid is part of the widget set for Xavvi/Livecode Create and the 
goal for that tool is to have things be super easy and super intuitive 
for beginners (non-code or low-code app building) so I think beginners 
would find thsi jarring.

So, is it a bug? What does the community think?

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