Element-extensions - FHIR v1.8.0

STU3 Candidate

This page is part of the FHIR Specification (v1.8.0: STU 3 Draft). The current version which supercedes this version is 5.0.0. For a full list of available versions, see the Directory of published versions . Page versions: R5 R4B R4 R3 R2

Element-definition Extensions for use by FHIR Implementers

Scope and Usage

This profile defines extensions that can be used to describe the additional characteristics that must be held by a data element.

Data elements can be defined in several places. The extensions defined within this profile may apply to most or all of these:

DataElement - defining the characteristics that must hold for an element to be an instance of a particular Data Element
Profile.structure.element.definition - defining the characteristics of the data element when used according to the profile
Profile.extensionDefn.definition - defining the characteristics of the extension, regardless of where it is used
Questionnaire.group.question - defining the characteristics of permitted answers

Note: Implementations are not required to reject invalid data. However, transmitting data that violates one of these extensions would be considered invalid against the resource that declared the extension.

The extensions provided here fall into several categories:

Length-related (govern allowed length of an element): minLength, maxLength
Format (govern the appearance of string and string-like simple data types): regex, entryFormat
Numeric/date (govern the allowed range of numeric, date or time data types): minValue, maxValue, maxDecimalPlaces
Attachment-related (govern allowed attachments): mimeType, maxSize

Content

Extensions:
minLength	At least this many characters : The minimum number of characters that must be present in the simple data type to be considered a "valid" instance.
regex	Regular expression pattern : A regular expression that defines the syntax for the data element to be considered valid.
entryFormat	User prompt for format : Additional instructions for the user to guide their input (i.e. a human readable version of a regular expression like "nnn-nnn-nnn"). In most UIs this is the placeholder (or 'ghost') text placed directly inside the edit controls and that disappear when the control gets the focus.
minValue	Must be >= this value : The inclusive lower bound on the range of allowed values for the data element.
maxValue	Must be <= this value : The inclusive upper bound on the range of allowed values for the data element.
maxDecimalPlaces	Maximum digits after decimal : Identifies the maximum number of decimal places that may be specified for the data element.
mimeType	Type of attachment : Identifies the kind(s) of attachmemt allowed to be sent for an element.
maxSize	Max size in MB : For attachment answers, indicates the maximum size an attachment can be.