The formatted data that's stored in the dataset may not be in the same format you want/need to use at the presentation level (UI). If you are confident with the VCL approach, you may think you can format data through the TField.DisplayFormat property (either by adding persistent fields to your dataset and setting DisplayFormat at design time or by accessing it at runtime via code), and you would be right.
However, LiveBindings comes with a more general mechanism that allows us to format data by passing it through the binding (unidirectionally or bidirectionally): using the CustomFormat and CustomParse properties.
As we saw previously when we introduced the LiveBindings expression evaluation engine, expressions can be complex. The technology supports a number of powerful functionalities, such as methods and output converters, to make expressions flexible and rich. The same expressions and functionalities are available through the CustomFormat and CustomParse properties...
