Data Access (DAO)
The basics of document storage are managed by a number of generic data access layer (referred to as Data Access Objects or DAO) in the implementation code.
Individual documents are controlled by the DocDao, and Interfaces, which are always read only, are controlled the InterfaceDao. Finally the DocsDao is simply a collection of all the daos.
External, read only, resources can be accessed by the ‘external Dao’ pattern, for which
ConfigurableRestDocDao
provides an ‘out the box’ implementation that should be sufficient in most cases.
see External Data for more detail.
Basically a DocDao is built for each type in the GraphQL schema and an InterfaceDao for each interface unless there is a Dao registered to access this resource as external data.
The rules for saving, retrieving and searching each DocDao are then driven from the GraphQL schema.
This layer of the design essentially leverages a GraphQL schema to build a fairly standard resource style app that is exposed via a conventional REST style API. Probably more usefully, it is also used to drive data access for a full GraphQL query layer, see Fetchers.
A schematic of the basic wiring implemented by the DocsDao is below.
