PropertyHandle :: Previous - Provide previous instance in collection
The function locates the previous instance in a collection starting from the currently located one. When no instance is selected, the function selects the last valid instance.
When a filter has been defined for a collection, the function returns the previous valid instance according to the filter condition.
In case of read arrors, the function returns an error, which is difficult to differ fron end of collection. Hence, the more secure way of reading instances in a collection is calling Get(index) and GetCount() in order to determin the size of collection. In case of filter conditions for the collection, one may use GetRelativeCount() and GetAt(index).
The function returns YES when the question was answered positively. Otherwise it returns NO .
Implementation details
- read_opt
- Read option
The option forces the function to read the instance when it could be located.
Default: YES