Is there a way in the Form API to have a form element display in a table (think like a list of fees) where one of the rows value could be changed with AJAX from another form element?
For example, if the default 'Subscription fee' is $10, and I select a different 'Subscription Plan' method, when I click the option, how do I change that fee row to $20 or whatever the amount may be?
I am trying to utilize the #ajax framework as much as possible with the Form API but I am not seeing how this is easily achievable.
The way I have rendered the form is to assemble the header and rows, then output a form Item element with theme('table') as its #markup, but I am getting an HTML string instead of an actual data array to manipulate (which is its intent, but I need something to manipulate with JS/PHP).