execute method

@override List execute(List results, Map<String, dynamic> passed)

The iterable, nested function that evaluates the entire FHIRPath expression one object at a time

Implementation

@override
List execute(List results, Map<String, dynamic> passed) {
  final identifierName = value;

  final finalResults = [];
  final finalPrimitiveExtensions =
      List<dynamic>.filled(results.length, null, growable: false);

  final passedExtensions = passed[ExtensionParser.extensionKey];
  passed[ExtensionParser.extensionKey] = null;

  if (passed.isVersion(FhirVersion.r4)
      ? r4.resourceTypeFromStringMap.keys.contains(identifierName)
      : passed.isVersion(FhirVersion.r5)
          ? r5.resourceTypeFromStringMap.keys.contains(identifierName)
          : passed.isVersion(FhirVersion.dstu2)
              ? dstu2.resourceTypeFromStringMap.keys.contains(identifierName)
              : stu3.resourceTypeFromStringMap.keys
                      .contains(identifierName) &&
                  (passed.hasNoContext
                      ? false
                      : passed.context?['resourceType'] == identifierName)) {
    finalResults.add(passed.context);
  } else {
    results.forEachIndexed((i, r) {
      if (r is Map) {
        String jsonIdentifierName = identifierName;
        dynamic rValue = r[identifierName];
        if (rValue == null) {
          // Support for polymorphism:
          // If the key cannot be found in the r-map, then find
          // a key that starts with the same word, e.g. 'value' identifier will
          // match 'valueDateTime' key.
          r.forEach((k, v) {
            if (k.toString().startsWith(identifierName) &&
                polymorphicPrefixes.contains(identifierName) &&
                startsWithAPolymorphicPrefix(k.toString())) {
              rValue = v;
              jsonIdentifierName = k.toString();
            }
          });
        }

        final jsonPrimitiveExtension =
            r['_$jsonIdentifierName'] as Map<String, dynamic>?;
        if (jsonPrimitiveExtension != null) {
          finalPrimitiveExtensions[i] = jsonPrimitiveExtension['extension'];
        }

        if (rValue is List) {
          finalResults.addAll(rValue as Iterable);
        } else if (rValue != null) {
          finalResults.add(rValue);
        } else if (r['resourceType'] == identifierName) {
          finalResults.add(r);
        }
      } else {
        if (identifierName == 'extension') {
          // Special processing for extensions on primitives
          if (passedExtensions != null) {
            final extensionOnPrimitive = passedExtensions[i];
            if (extensionOnPrimitive != null) {
              finalResults.addAll(extensionOnPrimitive as Iterable);
            }
          } else {
            // This primitive does not have an extension
            // Do nothing.
          }
        }
      }
    });
  }

  passed[ExtensionParser.extensionKey] = finalPrimitiveExtensions;

  return finalResults;
}