[Typo3-dev] a question about TCA

[Mario Rimann]

On Sun, 13 Nov 2005 20:46:03 +0100, Thomas Hempel
<thomas at work.de> wrote:

> Hi Mario,
> 
> > Is there a way, to evaluate this second field via TCA. It's value
> > must not be larger (= later) than the first field.
> AFAIK there is no way to do this now.
> 
> You can check that with a hook in tcemain (processDatamap_preProcessFieldArray)

Hi Thomas

Thanks for your answer. Together with Roberts Article about using
existing hooks, I got a working solution.

Now my function just empties the field wich contains a wrong
value. That's a good beginning.

Do you (or someone else) have clue, on how to notify the user
about this behaviour? I think about either adding this yellow
exclamation-mark next to the field, or showing a pop-up with some
explanational text like "The field B must contain a smaller value
than field A".

I couldn't find anything about this.

Greetings,
Mario