#30 Var2Xxx: optional ErrorHandling parameter; Var2DateTimeStr/Var2DateStr raise for a value that cannot be converted

[Thomas Mueller]

Follow-up to [bugs:#63].

1. Var2Int, Var2Int64, Var2IntStr, Var2Dbl, Var2Ext, Var2DblStr and Var2Str in u_dzVariantUtils get the same optional parameter as the TryVar2Xxx functions, _ErrorHandling: TErrorHandlingEnum = ehRaiseException. With ehNoException they return the Default (or NullValue) also for a value that cannot be converted, instead of raising EVariantConvertError.

2. Var2DateTimeStr and Var2DateStr return the NullValue not only for Null and Empty, but also for a variant that cannot be converted to a date and for a date outside the range FormatDateTime can render (before 0001-01-01 or after MaxDateTime). They are changed to work like the other Var2Xxx functions: the NullValue for Null and Empty, EVariantConvertError for both other cases, and the same _ErrorHandling parameter to get the NullValue back.

Note: 2 changes the behaviour for existing callers, e.g. u_dzDbCreatorDescription and the code generated by the DbCreator wizard use Var2DateTimeStr.

[Thomas Mueller]

Fixed in revision #2438