iff and between example for FHIRPath

Encounter-Example.json

{
  "resourceType": "Encounter",
  "id": "f203",
  "text": {
    "status": "generated",
    "div": "<div xmlns=\"http://www.w3.org/1999/xhtml\"><p><b>Generated Narrative with Details</b></p><p><b>id</b>: f203</p><p><b>identifier</b>: Encounter_Roel_20130311 (TEMP)</p><p><b>status</b>: finished</p><h3>StatusHistories</h3><table><tr><td>-</td><td><b>Status</b></td><td><b>Period</b></td></tr><tr><td>*</td><td>arrived</td><td>08/03/2013 --&gt; (ongoing)</td></tr></table><p><b>class</b>: inpatient encounter (Details: http://terminology.hl7.org/CodeSystem/v3-ActCode code IMP = 'inpatient encounter', stated as 'inpatient encounter')</p><p><b>type</b>: Inpatient stay for nine days <span>(Details : {SNOMED CT code '183807002' = 'Inpatient stay 9 days', given as 'Inpatient stay for nine days'})</span></p><p><b>priority</b>: High priority <span>(Details : {SNOMED CT code '394849002' = 'High priority', given as 'High priority'})</span></p><p><b>subject</b>: <a>Roel</a></p><p><b>episodeOfCare</b>: <a>EpisodeOfCare/example</a></p><p><b>basedOn</b>: <a>ServiceRequest/myringotomy</a></p><h3>Participants</h3><table><tr><td>-</td><td><b>Type</b></td><td><b>Individual</b></td></tr><tr><td>*</td><td>Participation <span>(Details : {http://terminology.hl7.org/CodeSystem/v3-ParticipationType code 'PART' = 'Participation)</span></td><td><a>Practitioner/f201</a></td></tr></table><p><b>appointment</b>: <a>Appointment/example</a></p><p><b>period</b>: 11/03/2013 --&gt; 20/03/2013</p><p><b>reasonCode</b>: The patient seems to suffer from bilateral pneumonia and renal insufficiency, most likely due to chemotherapy. <span>(Details )</span></p><blockquote><p><b>diagnosis</b></p><p><b>condition</b>: <a>Condition/stroke</a></p><p><b>use</b>: Admission diagnosis <span>(Details : {http://terminology.hl7.org/CodeSystem/diagnosis-role code 'AD' = 'Admission diagnosis', given as 'Admission diagnosis'})</span></p><p><b>rank</b>: 1</p></blockquote><blockquote><p><b>diagnosis</b></p><p><b>condition</b>: <a>Condition/f201</a></p><p><b>use</b>: Discharge diagnosis <span>(Details : {http://terminology.hl7.org/CodeSystem/diagnosis-role code 'DD' = 'Discharge diagnosis', given as 'Discharge diagnosis'})</span></p></blockquote><p><b>account</b>: <a>Account/example</a></p><h3>Hospitalizations</h3><table><tr><td>-</td><td><b>Origin</b></td><td><b>AdmitSource</b></td><td><b>ReAdmission</b></td><td><b>DietPreference</b></td><td><b>SpecialCourtesy</b></td><td><b>SpecialArrangement</b></td><td><b>Destination</b></td></tr><tr><td>*</td><td><a>Location/2</a></td><td>Clinical Oncology Department <span>(Details : {SNOMED CT code '309902002' = 'Clinical oncology department', given as 'Clinical Oncology Department'})</span></td><td>readmitted <span>(Details : {[not stated] code 'null' = 'null', given as 'readmitted'})</span></td><td>Fluid balance regulation <span>(Details : {SNOMED CT code '276026009' = 'Fluid balance regulation', given as 'Fluid balance regulation'})</span></td><td>normal courtesy <span>(Details : {http://terminology.hl7.org/CodeSystem/v3-EncounterSpecialCourtesy code 'NRM' = 'normal courtesy', given as 'normal courtesy'})</span></td><td>Wheelchair <span>(Details : {http://terminology.hl7.org/CodeSystem/encounter-special-arrangements code 'wheel' = 'Wheelchair', given as 'Wheelchair'})</span></td><td><a>Location/2</a></td></tr></table><p><b>serviceProvider</b>: <a>Organization/2</a></p><p><b>partOf</b>: <a>Encounter/f203</a></p></div>"
  },
  "identifier": [
    {
      "use": "temp",
      "value": "Encounter_Roel_20130311"
    }
  ],
  "status": "finished",
  "statusHistory": [
    {
      "status": "arrived",
      "period": {
        "start": "2013-03-08"
      }
    }
  ],
  "class": {
    "system": "http://terminology.hl7.org/CodeSystem/v3-ActCode",
    "code": "IMP",
    "display": "inpatient encounter"
  },
  "type": [
    {
      "coding": [
        {
          "system": "http://snomed.info/sct",
          "code": "183807002",
          "display": "Inpatient stay for nine days"
        }
      ]
    }
  ],
  "priority": {
    "coding": [
      {
        "system": "http://snomed.info/sct",
        "code": "394849002",
        "display": "High priority"
      }
    ]
  },
  "subject": {
    "reference": "Patient/f201",
    "display": "Roel"
  },
  "episodeOfCare": [
    {
      "reference": "EpisodeOfCare/example"
    }
  ],
  "basedOn": [
    {
      "reference": "ServiceRequest/myringotomy"
    }
  ],
  "participant": [
    {
      "type": [
        {
          "coding": [
            {
              "system": "http://terminology.hl7.org/CodeSystem/v3-ParticipationType",
              "code": "PART"
            }
          ]
        }
      ],
      "individual": {
        "reference": "Practitioner/f201"
      }
    }
  ],
  "appointment": [
    {
      "reference": "Appointment/example"
    }
  ],
  "period": {
    "start": "2013-03-11",
    "end": "2013-03-20"
  },
  "reasonCode": [
    {
      "text": "The patient seems to suffer from bilateral pneumonia and renal insufficiency, most likely due to chemotherapy."
    }
  ],
  "diagnosis": [
    {
      "condition": {
        "reference": "Condition/stroke"
      },
      "use": {
        "coding": [
          {
            "system": "http://terminology.hl7.org/CodeSystem/diagnosis-role",
            "code": "AD",
            "display": "Admission diagnosis"
          }
        ]
      },
      "rank": 1
    },
    {
      "condition": {
        "reference": "Condition/f201"
      },
      "use": {
        "coding": [
          {
            "system": "http://terminology.hl7.org/CodeSystem/diagnosis-role",
            "code": "DD",
            "display": "Discharge diagnosis"
          }
        ]
      }
    }
  ],
  "account": [
    {
      "reference": "Account/example"
    }
  ],
  "hospitalization": {
    "origin": {
      "reference": "Location/2"
    },
    "admitSource": {
      "coding": [
        {
          "system": "http://snomed.info/sct",
          "code": "309902002",
          "display": "Clinical Oncology Department"
        }
      ]
    },
    "reAdmission": {
      "coding": [
        {
          "display": "readmitted"
        }
      ]
    },
    "dietPreference": [
      {
        "coding": [
          {
            "system": "http://snomed.info/sct",
            "code": "276026009",
            "display": "Fluid balance regulation"
          }
        ]
      }
    ],
    "specialCourtesy": [
      {
        "coding": [
          {
            "system": "http://terminology.hl7.org/CodeSystem/v3-EncounterSpecialCourtesy",
            "code": "NRM",
            "display": "normal courtesy"
          }
        ]
      }
    ],
    "specialArrangement": [
      {
        "coding": [
          {
            "system": "http://terminology.hl7.org/CodeSystem/encounter-special-arrangements",
            "code": "wheel",
            "display": "Wheelchair"
          }
        ]
      }
    ],
    "destination": {
      "reference": "Location/2"
    }
  },
  "serviceProvider": {
    "reference": "Organization/2"
  },
  "partOf": {
    "reference": "Encounter/f203"
  }
}

ExpressionTest

/*
 * (C) Copyright IBM Corp. 2020
 *
 * SPDX-License-Identifier: Apache-2.0
 */

package com.ibm.fhir.test;

import java.util.Collection;

import org.testng.annotations.Test;

import com.ibm.fhir.examples.ExamplesUtil;
import com.ibm.fhir.model.format.Format;
import com.ibm.fhir.model.parser.FHIRParser;
import com.ibm.fhir.model.resource.Encounter;
import com.ibm.fhir.path.FHIRPathNode;
import com.ibm.fhir.path.evaluator.FHIRPathEvaluator;
import com.ibm.fhir.path.evaluator.FHIRPathEvaluator.EvaluationContext;

public class ExpressionTest {
    @Test
    public void testProfileConstraint() throws Exception {
        Encounter enc = (Encounter) FHIRParser.parser(Format.JSON).parse(ExamplesUtil.resourceReader("enc.json"));

        String expr = "iif(period.start.exists() and period.end.exists(), between(period.start , period.end, 'days'), {})";
        FHIRPathEvaluator evaluator = FHIRPathEvaluator.evaluator();
        EvaluationContext evaluationContext = new EvaluationContext(enc);
        Collection<FHIRPathNode> tmpResults = evaluator.evaluate(evaluationContext, expr);
        System.out.println(tmpResults);
        
        //Output as `[9 'days']`
    }
}