This page is part of the FHIR Core Extensions Registry (v5.1.0: Release 5.1) based on FHIR (HL7® FHIR® Standard) v5.0.0. This is the current published version in its permanent home (it will always be available at this URL). For a full list of available versions, see the Directory of published versions
Page standards status: Trial-use | Maturity Level: 3 |
XML representation of the variable extension.
<StructureDefinition xmlns="http://hl7.org/fhir">
<id value="variable"/>
<text>
<status value="extensions"/>
<div xmlns="http://www.w3.org/1999/xhtml"><table border="0" cellpadding="0" cellspacing="0" style="border: 0px #F0F0F0 solid; font-size: 11px; font-family: verdana; vertical-align: top;"><tr style="border: 1px #F0F0F0 solid; font-size: 11px; font-family: verdana; vertical-align: top"><th style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="The logical name of the element">Name</a></th><th style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Information about the use of the element">Flags</a></th><th style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Minimum and Maximum # of times the the element can appear in the instance">Card.</a></th><th style="width: 100px" class="hierarchy"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Reference to the type of the element">Type</a></th><th style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Additional information about the element">Description & Constraints</a><span style="float: right"><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Legend for this format"><img src="data:image/png;base64,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" alt="doco" style="background-color: inherit"/></a></span></th></tr><tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: white"><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck1.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_element.gif" alt="." style="background-color: white; background-color: inherit" title="Element" class="hierarchy"/> <a href="StructureDefinition-variable-definitions.html#Extension" title="Variable specifying a logic to generate a variable for use in subsequent logic. The name of the variable will be added to FHIRPath's context when processing descendants of the element that contains this extension as well as extensions within the same element.">Extension</a><a name="Extension"> </a></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a style="padding-left: 3px; padding-right: 3px; border: 1px maroon solid; font-weight: bold; color: #301212; background-color: #fdf4f4;" href="http://hl7.org/fhir/R5/conformance-rules.html#constraints" title="This element has or is affected by constraints (var-1)">C</a></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy">0..*</td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="http://hl7.org/fhir/R5/extensibility.html#Extension">Extension</a></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy">Variable for processing<br/><span style="font-weight:bold">var-1: </span>Variable expressions must have a name<br/></td></tr>
<tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: #F7F7F7"><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck10.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_vjoin.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_extension_simple.png" alt="." style="background-color: #F7F7F7; background-color: inherit" title="Simple Extension" class="hierarchy"/> <span style="text-decoration:line-through">extension</span><a name="Extension.extension"> </a></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="text-decoration:line-through"/><span style="text-decoration:line-through">0</span><span style="text-decoration:line-through">..</span><span style="text-decoration:line-through">0</span></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/></tr>
<tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: white"><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck10.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_vjoin.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_element.gif" alt="." style="background-color: white; background-color: inherit" title="Element" class="hierarchy"/> <a href="StructureDefinition-variable-definitions.html#Extension.url">url</a><a name="Extension.url"> </a></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">1</span><span style="opacity: 0.5">..</span><span style="opacity: 0.5">1</span></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a style="opacity: 0.5" href="http://hl7.org/fhir/R5/datatypes.html#uri">uri</a></td><td style="vertical-align: top; text-align : left; background-color: white; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="color: darkgreen">"http://hl7.org/fhir/StructureDefinition/variable"</span></td></tr>
<tr style="border: 0px #F0F0F0 solid; padding:0px; vertical-align: top; background-color: #F7F7F7"><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px; white-space: nowrap; background-image: url(tbl_bck00.png)" class="hierarchy"><img src="tbl_spacer.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="tbl_vjoin_end.png" alt="." style="background-color: inherit" class="hierarchy"/><img src="icon_datatype.gif" alt="." style="background-color: #F7F7F7; background-color: inherit" title="Data Type" class="hierarchy"/> <a href="StructureDefinition-variable-definitions.html#Extension.value[x]">value[x]</a><a name="Extension.value_x_"> </a></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"/><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy">1..<span style="opacity: 0.5">1</span></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><a href="http://hl7.org/fhir/R5/metadatatypes.html#Expression">Expression</a></td><td style="vertical-align: top; text-align : left; background-color: #F7F7F7; border: 0px #F0F0F0 solid; padding:0px 4px 0px 4px" class="hierarchy"><span style="opacity: 0.5">Value of extension</span></td></tr>
<tr><td colspan="5" class="hierarchy"><br/><a href="https://build.fhir.org/ig/FHIR/ig-guidance/readingIgs.html#table-views" title="Legend for this format"><img src="data:image/png;base64,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" alt="doco" style="background-color: inherit"/> Documentation for this format</a></td></tr></table></div>
</text>
<extension
url="http://hl7.org/fhir/StructureDefinition/structuredefinition-wg">
<valueCode value="fhir"/>
</extension>
<extension
url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm">
<valueInteger value="3"/>
</extension>
<extension
url="http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status">
<valueCode value="trial-use"/>
</extension>
<extension
url="http://hl7.org/fhir/StructureDefinition/structuredefinition-type-characteristics">
<valueCode value="can-bind"/>
</extension>
<url value="http://hl7.org/fhir/StructureDefinition/variable"/>
<identifier>
<system value="urn:ietf:rfc:3986"/>
<value value="urn:oid:2.16.840.1.113883.4.642.5.1528"/>
</identifier>
<version value="5.1.0"/>
<name value="Variable"/>
<title value="Variable"/>
<status value="active"/>
<experimental value="false"/>
<date value="2013-12-05"/>
<publisher value="HL7 International / FHIR Infrastructure"/>
<contact>
<telecom>
<system value="url"/>
<value value="http://www.hl7.org/Special/committees/fiwg"/>
</telecom>
</contact>
<description
value="Variable specifying a logic to generate a variable for use in subsequent logic. The name of the variable will be added to FHIRPath's context when processing descendants of the element that contains this extension as well as extensions within the same element."/>
<jurisdiction>
<coding>
<system value="http://unstats.un.org/unsd/methods/m49/m49.htm"/>
<code value="001"/>
</coding>
</jurisdiction>
<fhirVersion value="5.0.0"/>
<mapping>
<identity value="rim"/>
<uri value="http://hl7.org/v3"/>
<name value="RIM Mapping"/>
</mapping>
<kind value="complex-type"/>
<abstract value="false"/>
<context>
<type value="element"/>
<expression value="Questionnaire"/>
</context>
<context>
<type value="element"/>
<expression value="Questionnaire.item"/>
</context>
<context>
<type value="element"/>
<expression value="PlanDefinition"/>
</context>
<context>
<type value="element"/>
<expression value="PlanDefinition.action"/>
</context>
<context>
<type value="element"/>
<expression value="RequestOrchestration"/>
</context>
<context>
<type value="element"/>
<expression value="RequestOrchestration.action"/>
</context>
<context>
<type value="element"/>
<expression value="ActivityDefinition"/>
</context>
<context>
<type value="element"/>
<expression value="Measure"/>
</context>
<context>
<type value="element"/>
<expression value="Measure.group"/>
</context>
<context>
<type value="element"/>
<expression value="Measure.group.population"/>
</context>
<type value="Extension"/>
<baseDefinition value="http://hl7.org/fhir/StructureDefinition/Extension"/>
<derivation value="constraint"/>
<snapshot>
<element id="Extension">
<path value="Extension"/>
<short value="Variable for processing"/>
<definition
value="Variable specifying a logic to generate a variable for use in subsequent logic. The name of the variable will be added to FHIRPath's context when processing descendants of the element that contains this extension as well as extensions within the same element."/>
<comment
value="Ordering of variable extension declarations is significant as variables declared in one repetition of this extension might be used in subsequent extension repetitions
For questionnaires, see additional guidance and examples in the [SDC implementation guide](http://hl7.org/fhir/uv/sdc/behavior.html#variable)."/>
<min value="0"/>
<max value="*"/>
<base>
<path value="Extension"/>
<min value="0"/>
<max value="*"/>
</base>
<constraint>
<key value="ele-1"/>
<severity value="error"/>
<human value="All FHIR elements must have a @value or children"/>
<expression
value="hasValue() or (children().count() > id.count())"/>
<source value="http://hl7.org/fhir/StructureDefinition/Element"/>
</constraint>
<constraint>
<key value="ext-1"/>
<severity value="error"/>
<human value="Must have either extensions or value[x], not both"/>
<expression value="extension.exists() != value.exists()"/>
<source value="http://hl7.org/fhir/StructureDefinition/Extension"/>
</constraint>
<constraint>
<key value="var-1"/>
<severity value="error"/>
<human value="Variable expressions must have a name"/>
<expression value="value.name.exists()"/>
</constraint>
<isModifier value="false"/>
</element>
<element id="Extension.id">
<path value="Extension.id"/>
<representation value="xmlAttr"/>
<short value="Unique id for inter-element referencing"/>
<definition
value="Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces."/>
<min value="0"/>
<max value="1"/>
<base>
<path value="Element.id"/>
<min value="0"/>
<max value="1"/>
</base>
<type>
<extension
url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
<valueUrl value="id"/>
</extension>
<code value="http://hl7.org/fhirpath/System.String"/>
</type>
<condition value="ele-1"/>
<isModifier value="false"/>
<isSummary value="false"/>
<mapping>
<identity value="rim"/>
<map value="n/a"/>
</mapping>
</element>
<element id="Extension.extension">
<path value="Extension.extension"/>
<slicing>
<discriminator>
<type value="value"/>
<path value="url"/>
</discriminator>
<description value="Extensions are always sliced by (at least) url"/>
<rules value="open"/>
</slicing>
<short value="Extension"/>
<definition value="An Extension"/>
<min value="0"/>
<max value="0"/>
<base>
<path value="Element.extension"/>
<min value="0"/>
<max value="*"/>
</base>
<type>
<code value="Extension"/>
</type>
<constraint>
<key value="ele-1"/>
<severity value="error"/>
<human value="All FHIR elements must have a @value or children"/>
<expression
value="hasValue() or (children().count() > id.count())"/>
<source value="http://hl7.org/fhir/StructureDefinition/Element"/>
</constraint>
<constraint>
<key value="ext-1"/>
<severity value="error"/>
<human value="Must have either extensions or value[x], not both"/>
<expression value="extension.exists() != value.exists()"/>
<source value="http://hl7.org/fhir/StructureDefinition/Extension"/>
</constraint>
<isModifier value="false"/>
<isSummary value="false"/>
</element>
<element id="Extension.url">
<path value="Extension.url"/>
<representation value="xmlAttr"/>
<short value="identifies the meaning of the extension"/>
<definition
value="Source of the definition for the extension code - a logical name or a URL."/>
<comment
value="The definition may point directly to a computable or human-readable definition of the extensibility codes, or it may be a logical URI as declared in some other specification. The definition SHALL be a URI for the Structure Definition defining the extension."/>
<min value="1"/>
<max value="1"/>
<base>
<path value="Extension.url"/>
<min value="1"/>
<max value="1"/>
</base>
<type>
<extension
url="http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type">
<valueUrl value="uri"/>
</extension>
<code value="http://hl7.org/fhirpath/System.String"/>
</type>
<fixedUri value="http://hl7.org/fhir/StructureDefinition/variable"/>
<isModifier value="false"/>
<isSummary value="false"/>
<mapping>
<identity value="rim"/>
<map value="N/A"/>
</mapping>
</element>
<element id="Extension.value[x]">
<path value="Extension.value[x]"/>
<short value="Value of extension"/>
<definition
value="Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/R5/extensibility.html) for a list)."/>
<min value="1"/>
<max value="1"/>
<base>
<path value="Extension.value[x]"/>
<min value="0"/>
<max value="1"/>
</base>
<type>
<code value="Expression"/>
</type>
<condition value="ext-1"/>
<constraint>
<key value="ele-1"/>
<severity value="error"/>
<human value="All FHIR elements must have a @value or children"/>
<expression
value="hasValue() or (children().count() > id.count())"/>
<source value="http://hl7.org/fhir/StructureDefinition/Element"/>
</constraint>
<isModifier value="false"/>
<isSummary value="false"/>
<mapping>
<identity value="rim"/>
<map value="N/A"/>
</mapping>
</element>
</snapshot>
<differential>
<element id="Extension">
<path value="Extension"/>
<short value="Variable for processing"/>
<definition
value="Variable specifying a logic to generate a variable for use in subsequent logic. The name of the variable will be added to FHIRPath's context when processing descendants of the element that contains this extension as well as extensions within the same element."/>
<comment
value="Ordering of variable extension declarations is significant as variables declared in one repetition of this extension might be used in subsequent extension repetitions
For questionnaires, see additional guidance and examples in the [SDC implementation guide](http://hl7.org/fhir/uv/sdc/behavior.html#variable)."/>
<min value="0"/>
<max value="*"/>
<constraint>
<key value="var-1"/>
<severity value="error"/>
<human value="Variable expressions must have a name"/>
<expression value="value.name.exists()"/>
</constraint>
</element>
<element id="Extension.extension">
<path value="Extension.extension"/>
<max value="0"/>
</element>
<element id="Extension.url">
<path value="Extension.url"/>
<fixedUri value="http://hl7.org/fhir/StructureDefinition/variable"/>
</element>
<element id="Extension.value[x]">
<path value="Extension.value[x]"/>
<min value="1"/>
<type>
<code value="Expression"/>
</type>
</element>
</differential>
</StructureDefinition>