| Contents: | Main | Section | See Also: | User Manual | Advanced User Manual |
The target data model should drive the definition of the Entity. The name of the class is the Display Name of the Entity. If SDA or FHIR, entities can be tagged as such and will be indexed for quick access. The primary source of the data in VistA should be defined as the Default File Number, where most if not all desired property values are stored.
Usually, an Entity maps a single record from a VistA file to an instance of a class, accepting a record internal entry number (IEN) as the identifier. Search parameters can be defined to fetch multiple records at a time, using the Entity as a template for producing each result.
The Entity ITEM (#1.51) subfile is a list of property names, each usually linked to a VistA field. Fields are assumed to be from the Default File Number, unless otherwise specified in the Item definition.
Properties are evaluated in sequence as defined. Various attributes for an Item can be defined depending on the Item Type. Simple strings can be returned, such as a fixed string or a single field value, or complex groups of multiple fields or values.
Each Entity can include additional M code fields for SETting and KILLing Entity-wide variables or performing any needed validation or set-up tasks before attempting to fetch any single record.
A flag can be set in any of these code fields to quit if a property or record should not be returned.
Reviewed/Updated: May 2026