Session state protection and read-only items

Question

I have a requirement to create a report + form for a database table. In the form, there is mandatory database column that needs to be displayed but it should be read-only and its value derived using values entered elsewhere on the screen.
It tried Display Only, Read Only and Disabled but they either fall foul of session state protection violation or ORA-01400: cannot insert NULL. The best method that I've found was to add readonly="readonly" the item element, but this causes the input item to lose its APEX classes and I'd prefer a declarative solution anyway.
Anyone know the best approach?
I've created a DEMO - http://apex.oracle.com/pls/apex/f?p=READONLY - which demonstrates the 4 methods.
Edited by: KGelling on 17-May-2012 06:10

Answer 1

KGelling wrote:
The best method that I've found was to add readonly="readonly" the item element, but this causes the input item to lose its APEX classes and I'd prefer a declarative solution anyway.Looks like a bug to me. However a possible explanation/justification for this behaviour is that the HTML Form Element Attributes are often used to specify a custom class for the item, so the default class is removed to prevent any conflicts. IMO APEX needs to provide declarative support for the use of multiple, space-separated class values in page, region, item etc attributes.
As a workaround in this case, just include the class in the HTML Form Element Attributes:
class="number_field" readonly="readonly"
I've created a DEMO - http://apex.oracle.com/pls/apex/f?p=READONLY - which demonstrates the 4 methods.
Thanks for making the effort.