Merge pull request #184 from networknt/issue183

Issue183

Author: stevehu

src/main/java/com/networknt/schema/EnumValidator.java

@@ -17,6 +17,8 @@
 package com.networknt.schema;
 
 import com.fasterxml.jackson.databind.JsonNode;
+import com.fasterxml.jackson.databind.node.NullNode;
+
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;
 
@@ -49,6 +51,17 @@ public EnumValidator(String schemaPath, JsonNode schemaNode, JsonSchema parentSc
                 separator = ", ";
             }
 
+            // check if the parent schema declares the fields as nullable
+            if(config.isHandleNullableField()) {
+	            JsonNode nullable = parentSchema.getSchemaNode().get("nullable");
+	            if (nullable != null && nullable.asBoolean()) {
+	            	nodes.add(NullNode.getInstance());
+	            	separator = ", ";
+	            	sb.append(separator);
+	            	sb.append("null");
+	            }
+            }
+            //
             sb.append(']');
 
             error = sb.toString();

src/main/java/com/networknt/schema/SchemaValidatorsConfig.java

@@ -38,6 +38,16 @@ public class SchemaValidatorsConfig {
      */
     private Map<String, String> uriMappings = new HashMap<String, String>();
 
+    /**
+     * When a field is set as nullable in the OpenAPI specification, the schema validator validates that it is nullable
+     * however continues with validation against the nullable field
+     * 
+     * If handleNullableField is set to true && incoming field is nullable && value is field: null --> succeed
+     * If handleNullableField is set to false && incoming field is nullable && value is field: null --> it is up to the type 
+     * validator using the SchemaValidator to handle it.
+     */
+    private boolean handleNullableField = true;
+    
     public boolean isTypeLoose() {
         return typeLoose;
     }
@@ -63,7 +73,15 @@ public void setMissingNodeAsError(boolean missingNodeAsError) {
     	this.missingNodeAsError = missingNodeAsError;
     }
 
-    public SchemaValidatorsConfig() {
+    public boolean isHandleNullableField() {
+		return handleNullableField;
+	}
+
+	public void setHandleNullableField(boolean handleNullableField) {
+		this.handleNullableField = handleNullableField;
+	}
+
+	public SchemaValidatorsConfig() {
         loadDefaultConfig();
     }