How to automatically call a function when a column is modified?

jeff3928

I have a character column in a data table which allows the user to change the data via a list check. The column is prefilled with values and I need a way to detect when the user changes a value in the column so I can call a function that re-colors the rows accordingly. Subscribing to the datatable won't work because I need to detect changes in existing rows and not the addition of new ones. Is there some way to do this with MakeRowStateHandler? I made an attempt but ended up with too many recursions because the called function actually changes the row states and this re-triggers the row state handler.

pmroz

This is a bit of a kluge but should work:

Let's suppose your character column is called A.

Create two hidden columns, B and C:

1. B is a copy of column A

2. C is a formula column who's formula is:

     a. Do the two columns A and B have the same value?

     b. If yes do nothing.

     c. If no call your function, and then set the B equal to the new value of A

You might get some ideas on formula columns for step 2 from my poster: http://www.jmp.com/about/events/summit2011/protected/Poster11_PeterMroz.pdf

See section 4, where a table cell acts like a hyperlink.  This approach might not be what you need, as I needed the user to just click on a column cell for things to happen.