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Re: 20030516: DataChoices

Paul
> 
>   I'll bet you thought I was gone...you're not so lucky :)  Here's an easy
> question: what are the differences between DataChoice types
> (DirectDataChoice, DerivedDataChoice, UnboundDataChoice, etc)?  The JavaDoc
> is a little sparse for those classes.

Here is what I understand.
If is is not enough to get started please ask particular questions.

DirectDataChoice is associated with  a real DataSource and gets the data
from the datasource.
This is what you use when you are reading data from a file, to display
that data.

DerivedDataChoice has some operands and makes a new data object from
them.
Used for "derived parameters" computed from data fields read in from
sources
outside the IDV.

UnboundDataChoice is used for the operands in a DerivedDataChoice, and
has data filled
by the DerivedDataChoice processing. So it is a holder for temporary
data inside the IDV
and I don't expect ever shows up in the data selector window.

UserDataChoice holds a value that the user entered.

Source code documentation was scanty but now Jeff McWhirter and Don are
actively putting
in javadoc and much of that is supposed to complete for the June IDV
release.

Stu Wier

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