{
  "description": "Indicates that the reference has a  particular focus in the target resource, a particular element of interest, identified by a FHIRPath statement. The FHIRPath expression is limited to a the [simple subset](fhirpath.html#simple) with the additional limitation that .resolve() that is not allowed. This is a more sophisticated mechanism of referring to an element than [[[http://hl7.org/fhir/StructureDefinition/targetElement]]] but does require the system resolving the item to be able to use at least FHIRPath.  If the author of the reference has the ability to ensure an id will be present on the target [[[http://hl7.org/fhir/StructureDefinition/targetElement]]] might be more widely useable.",
  "_filename": "StructureDefinition-targetPath.json",
  "package_name": "hl7.fhir.uv.extensions.r4b",
  "date": "2015-02-28",
  "derivation": "constraint",
  "publisher": "HL7 International / FHIR Infrastructure",
  "fhirVersion": "4.3.0",
  "jurisdiction": [ {
    "coding": [ {
      "code": "001",
      "system": "http://unstats.un.org/unsd/methods/m49/m49.htm"
    } ]
  } ],
  "name": "TargetPath",
  "mapping": [ {
    "uri": "http://hl7.org/v3",
    "name": "RIM Mapping",
    "identity": "rim"
  } ],
  "abstract": false,
  "type": "Extension",
  "experimental": "false",
  "resourceType": "StructureDefinition",
  "title": "Target path",
  "package_version": "5.3.0-ballot-tc",
  "extension": [ {
    "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-wg",
    "valueCode": "fhir"
  }, {
    "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fmm",
    "valueInteger": 2
  }, {
    "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-standards-status",
    "valueCode": "trial-use"
  }, {
    "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-type-characteristics",
    "valueCode": "can-bind"
  } ],
  "snapshot": {
    "element": [ {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children unless an empty Parameters resource",
        "xpath": "@value|f:*|h:div|self::f:Parameters",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count()) or $this is Parameters"
      }, {
        "key": "ext-1",
        "human": "Must have either extensions or value[x], not both",
        "xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), 'value')])",
        "source": "http://hl7.org/fhir/StructureDefinition/Extension",
        "severity": "error",
        "expression": "extension.exists() != value.exists()"
      } ],
      "path": "Extension",
      "min": 0,
      "definition": "Indicates that the reference has a  particular focus in the target resource, a particular element of interest, identified by a FHIRPath statement. The FHIRPath expression is limited to a the [simple subset](fhirpath.html#simple) with the additional limitation that .resolve() that is not allowed. This is a more sophisticated mechanism of referring to an element than [[[http://hl7.org/fhir/StructureDefinition/targetElement]]] but does require the system resolving the item to be able to use at least FHIRPath.  If the author of the reference has the ability to ensure an id will be present on the target [[[http://hl7.org/fhir/StructureDefinition/targetElement]]] might be more widely useable.",
      "isModifier": false,
      "short": "A particular element of interest in the target resource (by limited FHIRPath)",
      "max": "*",
      "id": "Extension",
      "condition": [ "ele-1" ],
      "comment": "This extension can be used when the target element has no explicit id associated with it. When there is an id on the telement of interest, the extension [http://hl7.org/fhir/StructureDefinition/targetElement](StructureDefinition-targetElement.html) can be used since it is much simpler to implement.",
      "base": {
        "max": "*",
        "min": 0,
        "path": "Extension"
      }
    }, {
      "path": "Extension.id",
      "min": 0,
      "definition": "Unique id for the element within a resource (for internal references). This may be any string value that does not contain spaces.",
      "isModifier": false,
      "short": "Unique id for inter-element referencing",
      "mapping": [ {
        "map": "n/a",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "http://hl7.org/fhirpath/System.String",
        "extension": [ {
          "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
          "valueUrl": "id"
        } ]
      } ],
      "representation": [ "xmlAttr" ],
      "max": "1",
      "id": "Extension.id",
      "base": {
        "max": "1",
        "min": 0,
        "path": "Element.id"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "xpath": "@value|f:*|h:div",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      }, {
        "key": "ext-1",
        "human": "Must have either extensions or value[x], not both",
        "xpath": "exists(f:extension)!=exists(f:*[starts-with(local-name(.), \"value\")])",
        "source": "http://hl7.org/fhir/StructureDefinition/Extension",
        "severity": "error",
        "expression": "extension.exists() != value.exists()"
      } ],
      "path": "Extension.extension",
      "min": 0,
      "definition": "An Extension",
      "isModifier": false,
      "short": "Extension",
      "slicing": {
        "rules": "open",
        "description": "Extensions are always sliced by (at least) url",
        "discriminator": [ {
          "path": "url",
          "type": "value"
        } ]
      },
      "type": [ {
        "code": "Extension"
      } ],
      "max": "0",
      "id": "Extension.extension",
      "base": {
        "max": "*",
        "min": 0,
        "path": "Element.extension"
      },
      "isSummary": false
    }, {
      "path": "Extension.url",
      "min": 1,
      "definition": "Source of the definition for the extension code - a logical name or a URL.",
      "isModifier": false,
      "short": "identifies the meaning of the extension",
      "fixedUri": "http://hl7.org/fhir/StructureDefinition/targetPath",
      "mapping": [ {
        "map": "N/A",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "http://hl7.org/fhirpath/System.String",
        "extension": [ {
          "url": "http://hl7.org/fhir/StructureDefinition/structuredefinition-fhir-type",
          "valueUrl": "uri"
        } ]
      } ],
      "representation": [ "xmlAttr" ],
      "max": "1",
      "id": "Extension.url",
      "comment": "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.",
      "base": {
        "max": "1",
        "min": 1,
        "path": "Extension.url"
      },
      "isSummary": false
    }, {
      "constraint": [ {
        "key": "ele-1",
        "human": "All FHIR elements must have a @value or children",
        "xpath": "@value|f:*|h:div",
        "source": "http://hl7.org/fhir/StructureDefinition/Element",
        "severity": "error",
        "expression": "hasValue() or (children().count() > id.count())"
      } ],
      "path": "Extension.value[x]",
      "min": 1,
      "definition": "Value of extension - must be one of a constrained set of the data types (see [Extensibility](http://hl7.org/fhir/R4B/extensibility.html) for a list).",
      "isModifier": false,
      "short": "Value of extension",
      "mapping": [ {
        "map": "N/A",
        "identity": "rim"
      } ],
      "type": [ {
        "code": "string"
      } ],
      "max": "1",
      "id": "Extension.value[x]",
      "base": {
        "max": "1",
        "min": 0,
        "path": "Extension.value[x]"
      },
      "isSummary": false
    } ],
    "extension": [ {
      "url": "http://hl7.org/fhir/tools/StructureDefinition/snapshot-base-version",
      "valueString": "4.3.0"
    } ]
  },
  "status": "active",
  "id": "23dcf229-30c7-40ef-9863-d2faac83f4e5",
  "kind": "complex-type",
  "url": "http://hl7.org/fhir/StructureDefinition/targetPath",
  "identifier": [ {
    "value": "urn:oid:2.16.840.1.113883.4.642.5.1670",
    "system": "urn:ietf:rfc:3986"
  } ],
  "context": [ {
    "type": "element",
    "expression": "Reference"
  }, {
    "type": "element",
    "extension": [ {
      "url": "http://hl7.org/fhir/StructureDefinition/version-specific-use",
      "extension": [ {
        "url": "startFhirVersion",
        "valueCode": "4.0"
      } ]
    } ],
    "expression": "canonical"
  } ],
  "version": "5.3.0-ballot-tc",
  "differential": {
    "element": [ {
      "id": "Extension",
      "max": "*",
      "min": 0,
      "path": "Extension",
      "short": "A particular element of interest in the target resource (by limited FHIRPath)",
      "comment": "This extension can be used when the target element has no explicit id associated with it. When there is an id on the telement of interest, the extension [http://hl7.org/fhir/StructureDefinition/targetElement](StructureDefinition-targetElement.html) can be used since it is much simpler to implement.",
      "definition": "Indicates that the reference has a  particular focus in the target resource, a particular element of interest, identified by a FHIRPath statement. The FHIRPath expression is limited to a the [simple subset](fhirpath.html#simple) with the additional limitation that .resolve() that is not allowed. This is a more sophisticated mechanism of referring to an element than [[[http://hl7.org/fhir/StructureDefinition/targetElement]]] but does require the system resolving the item to be able to use at least FHIRPath.  If the author of the reference has the ability to ensure an id will be present on the target [[[http://hl7.org/fhir/StructureDefinition/targetElement]]] might be more widely useable."
    }, {
      "id": "Extension.extension",
      "max": "0",
      "path": "Extension.extension"
    }, {
      "id": "Extension.url",
      "path": "Extension.url",
      "fixedUri": "http://hl7.org/fhir/StructureDefinition/targetPath"
    }, {
      "id": "Extension.value[x]",
      "min": 1,
      "path": "Extension.value[x]",
      "type": [ {
        "code": "string"
      } ]
    } ]
  },
  "contact": [ {
    "telecom": [ {
      "value": "http://www.hl7.org/Special/committees/fiwg",
      "system": "url"
    } ]
  } ],
  "baseDefinition": "http://hl7.org/fhir/StructureDefinition/Extension"
}