[TYPO3-dev] $TCA TYPE: "inline" child field default value based on parent record field.

[Viktor Livakivskyi]

Hi, Koen 
 
> Is it possible to set the value of the parent record as the default 
> value of the child records?
> 
> Assume you have a general course 'Stress' with x (not default, but 
> entered by the user) minimum and x maximum participants.
> When you create a child record, you want this x min and x max value as 
> the default value for the child record min and max values.
> (They are mostly the same, but sometimes they can be different)
> In this way the user doesn't have to fill them all the time.

It is not exactly, what you want, but sort of: you may use TCA's placeholder feature [1] in combination with 'useOrOverridePlaceholder' mode [2]. In this case, I think, you still need to programm the FE logic by yourself, but at least BE will be more intuitive for editors.

[1]: http://docs.typo3.org/typo3cms/TCAReference/6.2/Reference/Columns/Input/Index.html#columns-input-properties-placeholder 
[2]: http://docs.typo3.org/typo3cms/TCAReference/6.2/Reference/Columns/Input/Index.html#columns-input-properties-mode