UndeclaredExtension (added by addExtension method) does not serialize to JSON format properly

[fwang0]

This bug is found in version 1.4.

The following test code in PatientProvider would generate correct XML document, but wrong JSON document. Note the valueReference in JSON format contains not reference with id.

@READ()
public Patient read(@IdParam IdType theId) {
Patient patient = new Patient();
patient.setBirthDate(new Date());
patient.addExtension().setUrl("test").setValue(new Reference(new Condition()));
return patient;
}

XML:

    </valueReference>

</extension>
<contained>
    <Condition xmlns="http://hl7.org/fhir">
        <id value="1"/>

    </Condition>

</contained>
<birthDate value="2016-03-30"/>

JSON:

{
  "resourceType": "Patient",
  "extension": [
    {
      "url": "test",
      "valueReference": {}
    }
  ],
  "contained": [
    {
      "resourceType": "Condition",
      "id": "1"
    }
  ],
  "birthDate": "2016-03-30"
}

[fwang0]

The following change in JsonParser.java solves the problem. Can you verify if the fix is correct?

diff --git a/hapi-fhir-base/src/main/java/ca/uhn/fhir/parser/JsonParser.java b/hapi-fhir-base/src/main/java/ca/uhn/fhir/parser/JsonParser.java
index a3c8a9a..f69ccb6 100644
--- a/hapi-fhir-base/src/main/java/ca/uhn/fhir/parser/JsonParser.java
+++ b/hapi-fhir-base/src/main/java/ca/uhn/fhir/parser/JsonParser.java
@@ -1509,7 +1509,7 @@ public class JsonParser extends BaseParser implements IParser {
                                if (childName == null) {
                                        childName = "value" + myContext.getElementDefinition(value.getClass()).getName();
                                }
-                               BaseRuntimeElementDefinition<?> childDef = myContext.getElementDefinition(value.getClass());
+                               BaseRuntimeElementDefinition<?> childDef = extDef.getChildElementDefinitionByDatatype(value.getClass());
                                if (childDef == null) {
                                        throw new ConfigurationException("Unable to encode extension, unregognized child element type: " + value.getClass().getCanonicalName());
                                }

The result is:
{ "resourceType": "Patient", "extension": [ { "url": "test", "valueReference": { "reference": "#1" } } ], "contained": [ { "resourceType": "Condition", "id": "1" } ], "birthDate": "2016-04-05" }

[jamesagnew]

I applied the patch, and it works perfectly. Awesome!

I'll commit this shortly, and make sure you get the credit. :)

[jamesagnew]

Ps- I always try to make sure that any who contributes patches gets credit in our changelog. If you want anything other than your github handle listed please feel free to let me know.

[fwang0]

My github handle works great :) Thanks James!