Provided that the HAT PDA stores any JSON-formatted data provided to it, it was important to us to design mechanisms for suitable
data retrieval. Data bundling in the HAT PDA allows for extremely flexible data transformations and filtering when retrieving data:
- picking specific parts (fields) of interest out of all the data available to avoid exposing data that is not required
for the specific application. If you visualise data in a table, this would look like vertically slicing the table.
- filtering only the data that is required, based on values of the data stored. Using the table analogy, this would look like horizontally slicing the table.
- interleaving data from different, potentially heterogeneous endpoints — think about location data coming in from a range of
different sources, when an application is only concerned with having the most recent longitude and latitude, no matter which application it has come from
- restructuring the data to the desired JSON format on the fly, for example to unify the structure of data from different
endpoints being interleaved or to reformat to something more convenient for the developer
The first step in the process is to understand Data Combinators.