This page is part of the FHIR Specification (v4.3.0-snapshot1: Release 4B Snapshot #1). 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
Modeling and Methodology Work Group | Maturity Level: N/A | Standards Status: Informative |
Raw JSON (canonical form + also see JSON Format Specification)
StructureDefinition for Expression
{ "resourceType" : "StructureDefinition", "id" : "Expression", "meta" : { "lastUpdated" : "2021-12-20T14:08:35.086+11:00" }, "text" : { "status" : "generated", "div" : "<div>!-- Snipped for Brevity --></div>" }, "extension" : [{ "url" : "http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status", "valueCode" : "trial-use" }], "url" : "http://hl7.org/fhir/StructureDefinition/Expression", "version" : "4.3.0-snapshot1", "name" : "Expression", "status" : "draft", "date" : "2021-12-20T14:08:35+11:00", "publisher" : "HL7 FHIR Standard", "contact" : [{ "telecom" : [{ "system" : "url", "value" : "http://hl7.org/fhir" }] }], "description" : "Base StructureDefinition for Expression Type: A expression that is evaluated in a specified context and returns a value. The context of use of the expression must specify the context in which the expression is evaluated, and how the result of the expression is used.", "fhirVersion" : "4.3.0-snapshot1", "mapping" : [{ "identity" : "rim", "uri" : "http://hl7.org/v3", "name" : "RIM Mapping" }], "kind" : "complex-type", "abstract" : false, "type" : "Expression", "baseDefinition" : "http://hl7.org/fhir/StructureDefinition/Element", "derivation" : "specialization", "snapshot" : { "element" : [{ "id" : "Expression", "extension" : [{ "url" : "http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status", "valueCode" : "trial-use" }], "path" : "Expression", "short" : "An expression that can be used to generate a value", "definition" : "A expression that is evaluated in a specified context and returns a value. The context of use of the expression must specify the context in which the expression is evaluated, and how the result of the expression is used.", "min" : 0, "max" : "*", "base" : { "path" : "Expression", "min" : 0, "max" : "*" }, "condition" : ["ele-1"], "constraint" : [{ "key" : "ele-1", "severity" : "error", "human" : "All FHIR elements must have a @value or children unless an empty Parameters resource", "expression" : "hasValue() or (children().count() > id.count()) or $this is Parameters", "xpath" : "@value|f:*|h:div|self::f:Parameters", "source" : "http://hl7.org/fhir/StructureDefinition/Element" }, { "key" : "exp-1", "severity" : "error", "human" : "An expression or a reference must be provided", "expression" : "expression.exists() or reference.exists()", "xpath" : "exists(f:expression) or exists(f:reference)", "source" : "http://hl7.org/fhir/StructureDefinition/Expression" }], "isModifier" : false, "mapping" : [{ "identity" : "rim", "map" : "n/a" }] }, { "id" : "Expression.id", "path" : "Expression.id", "representation" : ["xmlAttr"], "short" : "Unique id for inter-element referencing", "definition" : "Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.", "min" : 0, "max" : "1", "base" : { "path" : "Element.id", "min" : 0, "max" : "1" }, "type" : [{ "extension" : [{ "url" : "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type", "valueUrl" : "string" }], "code" : "http://hl7.org/fhirpath/System.String" }], "isModifier" : false, "isSummary" : false, "mapping" : [{ "identity" : "rim", "map" : "n/a" }] }, { "id" : "Expression.extension", "path" : "Expression.extension", "slicing" : { "discriminator" : [{ "type" : "value", "path" : "url" }], "description" : "Extensions are always sliced by (at least) url", "rules" : "open" }, "short" : "Additional content defined by implementations", "definition" : "May be used to represent additional information that is not part of the basic definition of the element. To make the use of extensions safe and manageable, there is a strict set of governance applied to the definition and use of extensions. Though any implementer can define an extension, there is a set of requirements that SHALL be met as part of the definition of the extension.", "comment" : "There can be no stigma associated with the use of extensions by any application, project, or standard - regardless of the institution or jurisdiction that uses or defines the extensions. The use of extensions is what allows the FHIR specification to retain a core level of simplicity for everyone.", "alias" : ["extensions", "user content"], "min" : 0, "max" : "*", "base" : { "path" : "Element.extension", "min" : 0, "max" : "*" }, "type" : [{ "code" : "Extension" }], "constraint" : [{ "key" : "ele-1", "severity" : "error", "human" : "All FHIR elements must have a @value or children", "expression" : "hasValue() or (children().count() > id.count())", "xpath" : "@value|f:*|h:div", "source" : "http://hl7.org/fhir/StructureDefinition/Element" }, { "key" : "ext-1", "severity" : "error", "human" : "Must have either extensions or value[x], not both", "expression" : "extension.exists() != value.exists()", "xpath" : "exists(f:extension)!=exists(f:*[starts-with(local-name(.), \"value\")])", "source" : "http://hl7.org/fhir/StructureDefinition/Extension" }], "isModifier" : false, "isSummary" : false, "mapping" : [{ "identity" : "rim", "map" : "n/a" }] }, { "id" : "Expression.description", "path" : "Expression.description", "short" : "Natural language description of the condition", "definition" : "A brief, natural language description of the condition that effectively communicates the intended semantics.", "min" : 0, "max" : "1", "base" : { "path" : "Expression.description", "min" : 0, "max" : "1" }, "type" : [{ "code" : "string" }], "constraint" : [{ "key" : "ele-1", "severity" : "error", "human" : "All FHIR elements must have a @value or children", "expression" : "hasValue() or (children().count() > id.count())", "xpath" : "@value|f:*|h:div", "source" : "http://hl7.org/fhir/StructureDefinition/Element" }], "isModifier" : false, "isSummary" : true }, { "id" : "Expression.name", "path" : "Expression.name", "short" : "Short name assigned to expression for reuse", "definition" : "A short name assigned to the expression to allow for multiple reuse of the expression in the context where it is defined.", "min" : 0, "max" : "1", "base" : { "path" : "Expression.name", "min" : 0, "max" : "1" }, "type" : [{ "code" : "id" }], "constraint" : [{ "key" : "ele-1", "severity" : "error", "human" : "All FHIR elements must have a @value or children", "expression" : "hasValue() or (children().count() > id.count())", "xpath" : "@value|f:*|h:div", "source" : "http://hl7.org/fhir/StructureDefinition/Element" }], "isModifier" : false, "isSummary" : true }, { "id" : "Expression.language", "path" : "Expression.language", "short" : "text/cql | text/fhirpath | application/x-fhir-query | etc.", "definition" : "The media type of the language for the expression.", "min" : 1, "max" : "1", "base" : { "path" : "Expression.language", "min" : 1, "max" : "1" }, "type" : [{ "code" : "code" }], "constraint" : [{ "key" : "ele-1", "severity" : "error", "human" : "All FHIR elements must have a @value or children", "expression" : "hasValue() or (children().count() > id.count())", "xpath" : "@value|f:*|h:div", "source" : "http://hl7.org/fhir/StructureDefinition/Element" }], "isModifier" : false, "isSummary" : true, "binding" : { "extension" : [{ "url" : "http://hl7.org/fhir/build/StructureDefinition/binding-definition", "valueString" : "The media type of the expression language." }, { "url" : "http://hl7.org/fhir/StructureDefinition/elementdefinition-maxValueSet", "valueCanonical" : "http://www.rfc-editor.org/bcp/bcp13.txt" }, { "url" : "http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName", "valueString" : "ExpressionLanguage" }], "strength" : "extensible", "valueSet" : "http://hl7.org/fhir/ValueSet/expression-language" } }, { "id" : "Expression.expression", "path" : "Expression.expression", "short" : "Expression in specified language", "definition" : "An expression in the specified language that returns a value.", "min" : 0, "max" : "1", "base" : { "path" : "Expression.expression", "min" : 0, "max" : "1" }, "type" : [{ "code" : "string" }], "constraint" : [{ "key" : "ele-1", "severity" : "error", "human" : "All FHIR elements must have a @value or children", "expression" : "hasValue() or (children().count() > id.count())", "xpath" : "@value|f:*|h:div", "source" : "http://hl7.org/fhir/StructureDefinition/Element" }], "isModifier" : false, "isSummary" : true }, { "id" : "Expression.reference", "path" : "Expression.reference", "short" : "Where the expression is found", "definition" : "A URI that defines where the expression is found.", "comment" : "If both a reference and an expression is found, the reference SHALL point to the same expression.", "min" : 0, "max" : "1", "base" : { "path" : "Expression.reference", "min" : 0, "max" : "1" }, "type" : [{ "code" : "uri" }], "constraint" : [{ "key" : "ele-1", "severity" : "error", "human" : "All FHIR elements must have a @value or children", "expression" : "hasValue() or (children().count() > id.count())", "xpath" : "@value|f:*|h:div", "source" : "http://hl7.org/fhir/StructureDefinition/Element" }], "isModifier" : false, "isSummary" : true }] }, "differential" : { "element" : [{ "id" : "Expression", "extension" : [{ "url" : "http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status", "valueCode" : "trial-use" }], "path" : "Expression", "short" : "An expression that can be used to generate a value", "definition" : "A expression that is evaluated in a specified context and returns a value. The context of use of the expression must specify the context in which the expression is evaluated, and how the result of the expression is used.", "min" : 0, "max" : "*", "constraint" : [{ "key" : "exp-1", "severity" : "error", "human" : "An expression or a reference must be provided", "expression" : "expression.exists() or reference.exists()", "xpath" : "exists(f:expression) or exists(f:reference)", "source" : "http://hl7.org/fhir/StructureDefinition/Expression" }] }, { "id" : "Expression.description", "path" : "Expression.description", "short" : "Natural language description of the condition", "definition" : "A brief, natural language description of the condition that effectively communicates the intended semantics.", "min" : 0, "max" : "1", "type" : [{ "code" : "string" }], "isSummary" : true }, { "id" : "Expression.name", "path" : "Expression.name", "short" : "Short name assigned to expression for reuse", "definition" : "A short name assigned to the expression to allow for multiple reuse of the expression in the context where it is defined.", "min" : 0, "max" : "1", "type" : [{ "code" : "id" }], "isSummary" : true }, { "id" : "Expression.language", "path" : "Expression.language", "short" : "text/cql | text/fhirpath | application/x-fhir-query | etc.", "definition" : "The media type of the language for the expression.", "min" : 1, "max" : "1", "type" : [{ "code" : "code" }], "isSummary" : true, "binding" : { "extension" : [{ "url" : "http://hl7.org/fhir/build/StructureDefinition/binding-definition", "valueString" : "The media type of the expression language." }, { "url" : "http://hl7.org/fhir/StructureDefinition/elementdefinition-maxValueSet", "valueCanonical" : "http://www.rfc-editor.org/bcp/bcp13.txt" }, { "url" : "http://hl7.org/fhir/StructureDefinition/elementdefinition-bindingName", "valueString" : "ExpressionLanguage" }], "strength" : "extensible", "valueSet" : "http://hl7.org/fhir/ValueSet/expression-language" } }, { "id" : "Expression.expression", "path" : "Expression.expression", "short" : "Expression in specified language", "definition" : "An expression in the specified language that returns a value.", "min" : 0, "max" : "1", "type" : [{ "code" : "string" }], "isSummary" : true }, { "id" : "Expression.reference", "path" : "Expression.reference", "short" : "Where the expression is found", "definition" : "A URI that defines where the expression is found.", "comment" : "If both a reference and an expression is found, the reference SHALL point to the same expression.", "min" : 0, "max" : "1", "type" : [{ "code" : "uri" }], "isSummary" : true }] } }
Usage note: every effort has been made to ensure that the examples are correct and useful, but they are not a normative part of the specification.