Overview

The rm.data_structures package contains two packages: the item_structure package and the history package. The first describes generic, path-addressable data structures, while the latter describes a generic notion of linear history, for recording events in past time. The data_structures package is illustrated in the UML diagram below.

RM data structures
Figure 1. rm.data_structures Package

The data_structures package itself contains a single class, DATA_STRUCTURE, which is the ancestor of all openEHR data structures. Its only feature is the function as_hierarchy, which is implemented by each subtype of DATA_STRUCTURE, in order to generate a physical representation of the structure in ISO 13606 form. The ISO 13606 form is usually less optimal than the openEHR form, but is compatible with the less semantically rich standard, and is guaranteed (in theory) to be comprehensible to other systems which support ISO 13606 as an interoperability standard.

Class Descriptions

DATA_STRUCTURE Class

  • Definition

  • Effective

  • BMM

  • UML

Class

DATA_STRUCTURE (abstract)

Description

Abstract parent class of all data structure types. Includes the as_hierarchy function which can generate the equivalent CEN EN13606 single hierarchy for each subtype’s physical representation. For example, the physical representation of an ITEM_LIST is List<ELEMENT>; its implementation of as_hierarchy will generate a CLUSTER containing the set of ELEMENT nodes from the list.

Inherit

LOCATABLE

Functions

Signature

Meaning

1..1

as_hierarchy (): ITEM

Hierarchical equivalent of the physical representation of each subtype, compatible with CEN EN 13606 structures.
DATA_STRUCTURE (abstract)

Abstract parent class of all data structure types. Includes the as_hierarchy function which can generate the equivalent CEN EN13606 single hierarchy for each subtype’s physical representation. For example, the physical representation of an ITEM_LIST is List<ELEMENT>; its implementation of as_hierarchy will generate a CLUSTER containing the set of ELEMENT nodes from the list.

Inherits: Any, PATHABLE, LOCATABLE

Attributes

LOCATABLE.name: DV_TEXT [1..1]

Runtime name of this fragment, used to build runtime paths. This is the term provided via a clinical application or batch process to name this EHR construct: its retention in the EHR faithfully preserves the original label by which this entry was known to end users.

LOCATABLE.archetype_node_id: String [1..1]

Design-time archetype identifier of this node taken from its generating archetype; used to build archetype paths. Always in the form of an at-code, e.g. at0005. This value enables a 'standardised' name for this node to be generated, by referring to the generating archetype local terminology.

At an archetype root point, the value of this attribute is always the stringified form of the archetype_id found in the archetype_details object.

LOCATABLE.uid: UID_BASED_ID [0..1]

Optional globally unique object identifier for root points of archetyped structures.

LOCATABLE.links: List<LINK> [0..1]

Links to other archetyped structures (data whose root object inherits from ARCHETYPED, such as ENTRY, SECTION and so on). Links may be to structures in other compositions.

LOCATABLE.archetype_details: ARCHETYPED [0..1]

Details of archetyping used on this node.

LOCATABLE.feeder_audit: FEEDER_AUDIT [0..1]

Audit trail from non-openEHR system of original commit of information forming the content of this node, or from a conversion gateway which has synthesised this node.

Functions

(abstract) Any.is_equal (
other: Any[1]
): Boolean [1..1]

Value equality: return True if this and other are attached to objects considered to be equal in value.

Parameters
other

Other object for comparison.

Any.equal alias "=", "==" (
other: Any[1]
): Boolean [1..1]

Reference equality for reference types, value equality for value types.

Parameters
other

Other object for comparison.

Any.instance_of (
a_type: String[1]
): Any [1..1]

Create new instance of a type.

Any.type_of (
an_object: Any[1]
): String [1..1]

Type name of an object as a string. May include generic parameters, as in "Interval<Time>".

Any.not_equal alias "!=", "≠" (
other: Ordered[1]
): Boolean [1..1]

True if current object not equal to other. Returns not equal().

PATHABLE.parent (): PATHABLE [1..1]

Parent of this node in a compositional hierarchy.

PATHABLE.item_at_path (
a_path: String[1]
): Any

Pre: path_unique (a_path) [1..1]

The item at a path (relative to this item); only valid for unique paths, i.e. paths that resolve to a single item.

PATHABLE.items_at_path (
a_path: String[1]
): List<Any> [0..1]

List of items corresponding to a non-unique path.

PATHABLE.path_exists (
a_path: String[1]
): Boolean

Pre: not a_path.is_empty [1..1]

True if the path exists in the data with respect to the current item.

PATHABLE.path_unique (
a_path: String[1]
): Boolean

Pre: path_exists (a_path) [1..1]

True if the path corresponds to a single item in the data.

PATHABLE.path_of_item (
a_loc: PATHABLE[1]
): String [1..1]

The path to an item relative to the root of this archetyped structure.

LOCATABLE.concept (): DV_TEXT [1..1]

Clinical concept of the archetype as a whole (= derived from the archetype_node_id' of the root node)

LOCATABLE.is_archetype_root (): Boolean [1..1]

True if this node is the root of an archetyped structure.

as_hierarchy (): ITEM [1..1]

Hierarchical equivalent of the physical representation of each subtype, compatible with CEN EN 13606 structures.

Invariants

LOCATABLE.Links_valid: links /= Void implies not links.is_empty

LOCATABLE.Archetyped_valid: is_archetype_root xor archetype_details = Void

LOCATABLE.Archetype_node_id_valid: not archetype_node_id.is_empty

 
{
    "name": "DATA_STRUCTURE",
    "documentation": "Abstract parent class of all data structure types. Includes the `_as_hierarchy_` function which can generate the equivalent CEN EN13606 single hierarchy for each subtype's physical representation. For example, the physical representation of an `ITEM_LIST` is `List<ELEMENT>`; its implementation of `_as_hierarchy_` will generate a `CLUSTER` containing the set of `ELEMENT` nodes from the list. ",
    "is_abstract": true,
    "ancestors": [
        "LOCATABLE"
    ],
    "functions": {
        "as_hierarchy": {
            "name": "as_hierarchy",
            "documentation": "Hierarchical equivalent of the physical representation of each subtype, compatible with CEN EN 13606 structures. ",
            "result": {
                "_type": "P_BMM_SIMPLE_TYPE",
                "type": "ITEM"
            }
        }
    }
}
DATA_STRUCTURE