Trifolia-on-FHIR

Elements

As the base type for all elements included in a resource, Element is an important structural element of FHIR. Even the primitive types inherit the base features and representation rules that apply to the Element type.

content:

• Extensions
• An internal id

There are 3 kinds of descendant types that specialize Element:

• Primitive data types, that add a primitive value property of the specified type
• Complex data types, that add their own children (all of which are also elements)
• BackboneElement, A specialization that adds modifierExtension, which is the super-type of all the element types defined in resource definitions (e.g. Patient.contact)

Note that resources themselves all specialize the base type Resource. For more information on the backbone element, visit https://www.hl7.org/fhir/backboneelement.html 

Element Definition in Trifolia on FHIR

• The profile editor loads the elements from the snapshot of the “base definition” profile. 
• If the base definition represents a profile that does not yet have a snapshot, it attempts to create a snapshot for the base definition profile.
• If the base definition has other base definition profiles that are not in the system, the snapshot it returns will simply be the core FHIR profile for the “type” selected (ex: the underlying profile for “Observation”)
• The “Base Definition” field should allow you to select pre-existing profiles that are based on a matching “type”, or the core FHIR specification’s profile for the underlying type. 
• Cardinality
• Users can set the cardinality of an element to an invalid value, but a Warning will appear in the Element Definition form and a Validation Error appears in the Validation tab if the user.
• selects a min cardinality less than the base element's min cardinality.
• selects a max cardinality greater than the base element's max cardinality.
  
  
• Maximum Field Length
• maxLength can only be entered when the ElementDefinition.type is a primitive type, with the exception of “boolean” (instant time date dateTime decimal integer string uri base64Binary code id oid unsignedInt positiveInt markdown url canonical uuid).
  
  
• Narrative 
• Short:  A concise description of what this element means (e.g. for use in autogenerated summaries).
• Text entered in "Short" will be displayed in the "Description & Constraints" column of the Differential Table for the profile.
  
  
• Definition:  Provides a complete explanation of the meaning of the data element for human readability. For the case of elements derived from existing elements (e.g. constraints), the definition SHALL be consistent with the base definition, but convey the meaning of the element in the particular context of use of the resource.
• Text entered in the "Definition" field will be displayed in the "Detailed Descriptions" page for the specific element.