[Typo3-dev] dynamic default value in TCA

[Mathieu Lecarme]

in my TCA forms, i'd like dynamic default value. In tt_news, for
example, i'd like the logued user for default writer, or in a book
module, i'd like default information from amazon distant API when i put
ISBN information.
The 3 hooks in tcemain, like processDatamap_postProcessFieldArray are
readonly, and values in $TCA is either userform or classical static form.

What is the best method for that problem?

M.