[CSharp] add optional flag "optionalEmitDefaultValues" and update template (#4010)

This commit addresses issue #3274 and adds the proposed optionalEmitDefaultValues flag.

bin/csharp-property-changed-petstore.sh

@@ -27,6 +27,6 @@ fi
 
 # if you've executed sbt assembly previously it will use that instead.
 export JAVA_OPTS="${JAVA_OPTS} -Xmx1024M -DloggerPath=conf/log4j.properties"
-ags="generate -i modules/openapi-generator/src/test/resources/2_0/petstore-with-fake-endpoints-models-for-testing.yaml -g csharp -o samples/client/petstore/csharp/OpenAPIClientWithPropertyChanged --additional-properties generatePropertyChanged=true --additional-properties packageGuid={5CD900DE-8266-412F-A758-28E1F9C623D5} $@"
+ags="generate -i modules/openapi-generator/src/test/resources/2_0/petstore-with-fake-endpoints-models-for-testing.yaml -g csharp -o samples/client/petstore/csharp/OpenAPIClientWithPropertyChanged --additional-properties generatePropertyChanged=true --additional-properties optionalEmitDefaultValues=true --additional-properties packageGuid={5CD900DE-8266-412F-A758-28E1F9C623D5} $@"
 
 java $JAVA_OPTS -jar $executable $ags

bin/openapi3/csharp-property-changed-petstore.sh

@@ -27,6 +27,6 @@ fi
 
 # if you've executed sbt assembly previously it will use that instead.
 export JAVA_OPTS="${JAVA_OPTS} -Xmx1024M -DloggerPath=conf/log4j.properties"
-ags="generate $@ -i modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml -g csharp -o samples/client/petstore/csharp/OpenAPIClientWithPropertyChanged --additional-properties generatePropertyChanged=true --additional-properties packageGuid={5CD900DE-8266-412F-A758-28E1F9C623D5}"
+ags="generate $@ -i modules/openapi-generator/src/test/resources/3_0/petstore-with-fake-endpoints-models-for-testing.yaml -g csharp -o samples/client/petstore/csharp/OpenAPIClientWithPropertyChanged --additional-properties generatePropertyChanged=true --additional-properties optionalEmitDefaultValues=true --additional-properties packageGuid={5CD900DE-8266-412F-A758-28E1F9C623D5}"
 
 java $JAVA_OPTS -jar $executable $ags

bin/windows/csharp-property-changed-petstore.bat

@@ -5,6 +5,6 @@ If Not Exist %executable% (
 )
 
 REM set JAVA_OPTS=%JAVA_OPTS% -Xmx1024M
-set ags=generate -i modules/openapi-generator/src/test/resources/2_0/petstore-with-fake-endpoints-models-for-testing.yaml -g csharp -o samples\client\petstore\csharp\SwaggerClientWithPropertyChanged --additional-properties=generatePropertyChanged=true,packageGuid={5CD900DE-8266-412F-A758-28E1F9C623D5}
+set ags=generate -i modules/openapi-generator/src/test/resources/2_0/petstore-with-fake-endpoints-models-for-testing.yaml -g csharp -o samples\client\petstore\csharp\SwaggerClientWithPropertyChanged --additional-properties=generatePropertyChanged=true,optionalEmitDefaultValues=true,packageGuid={5CD900DE-8266-412F-A758-28E1F9C623D5}
 
 java %JAVA_OPTS% -jar %executable% %ags%

docs/generators/csharp.md

@@ -21,6 +21,7 @@ sidebar_label: csharp
 |returnICollection|Return ICollection<T> instead of the concrete type.| |false|
 |optionalMethodArgument|C# Optional method argument, e.g. void square(int x=10) (.net 4.0+ only).| |true|
 |optionalAssemblyInfo|Generate AssemblyInfo.cs.| |true|
+|optionalEmitDefaultValues|Set DataMember's EmitDefaultValue.| |false|
 |optionalProjectFile|Generate {PackageName}.csproj.| |true|
 |generatePropertyChanged|Specifies a AssemblyDescription for the .NET Framework global assembly attributes stored in the AssemblyInfo file.| |false|
 |nonPublicApi|Generates code with reduced access modifiers; allows embedding elsewhere without exposing non-public API calls to consumers.| |false|

modules/openapi-generator/src/main/java/org/openapitools/codegen/CodegenConstants.java

@@ -168,6 +168,9 @@ public class CodegenConstants {
     public static final String OPTIONAL_ASSEMBLY_INFO = "optionalAssemblyInfo";
     public static final String OPTIONAL_ASSEMBLY_INFO_DESC = "Generate AssemblyInfo.cs.";
 
+    public static final String OPTIONAL_EMIT_DEFAULT_VALUES = "optionalEmitDefaultValues";
+    public static final String OPTIONAL_EMIT_DEFAULT_VALUES_DESC = "Set DataMember's EmitDefaultValue.";
+
     public static final String NETCORE_PROJECT_FILE = "netCoreProjectFile";
     public static final String NETCORE_PROJECT_FILE_DESC = "Use the new format (.NET Core) for .NET project files (.csproj).";
 

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/AbstractCSharpCodegen.java

@@ -39,6 +39,7 @@ import static org.openapitools.codegen.utils.StringUtils.camelize;
 public abstract class AbstractCSharpCodegen extends DefaultCodegen implements CodegenConfig {
 
     protected boolean optionalAssemblyInfoFlag = true;
+    protected boolean optionalEmitDefaultValuesFlag = false;
     protected boolean optionalProjectFileFlag = true;
     protected boolean optionalMethodArgumentFlag = true;
     protected boolean useDateTimeOffsetFlag = false;

modules/openapi-generator/src/main/java/org/openapitools/codegen/languages/CSharpClientCodegen.java

@@ -171,6 +171,10 @@ public class CSharpClientCodegen extends AbstractCSharpCodegen {
                 CodegenConstants.OPTIONAL_ASSEMBLY_INFO_DESC,
                 this.optionalAssemblyInfoFlag);
 
+        addSwitch(CodegenConstants.OPTIONAL_EMIT_DEFAULT_VALUES,
+                CodegenConstants.OPTIONAL_EMIT_DEFAULT_VALUES_DESC,
+                this.optionalEmitDefaultValuesFlag);
+
         addSwitch(CodegenConstants.OPTIONAL_PROJECT_FILE,
                 CodegenConstants.OPTIONAL_PROJECT_FILE_DESC,
                 this.optionalProjectFileFlag);
@@ -359,6 +363,12 @@ public class CSharpClientCodegen extends AbstractCSharpCodegen {
             additionalProperties.put(CodegenConstants.OPTIONAL_ASSEMBLY_INFO, optionalAssemblyInfoFlag);
         }
 
+        if (additionalProperties.containsKey(CodegenConstants.OPTIONAL_EMIT_DEFAULT_VALUES)) {
+            setOptionalEmitDefaultValuesFlag(convertPropertyToBooleanAndWriteBack(CodegenConstants.OPTIONAL_EMIT_DEFAULT_VALUES));
+        } else {
+            additionalProperties.put(CodegenConstants.OPTIONAL_EMIT_DEFAULT_VALUES, optionalEmitDefaultValuesFlag);
+        }
+
         if (additionalProperties.containsKey(CodegenConstants.NON_PUBLIC_API)) {
             setNonPublicApi(convertPropertyToBooleanAndWriteBack(CodegenConstants.NON_PUBLIC_API));
         } else {
@@ -537,6 +547,10 @@ public class CSharpClientCodegen extends AbstractCSharpCodegen {
         this.optionalAssemblyInfoFlag = flag;
     }
 
+    public void setOptionalEmitDefaultValuesFlag(boolean flag) {
+        this.optionalEmitDefaultValuesFlag = flag;
+    }
+
     @Override
     public CodegenModel fromModel(String name, Schema model) {
         Map<String, Schema> allDefinitions = ModelUtils.getSchemas(this.openAPI);
@@ -605,12 +619,14 @@ public class CSharpClientCodegen extends AbstractCSharpCodegen {
     @Override
     public void postProcessParameter(CodegenParameter parameter) {
         postProcessPattern(parameter.pattern, parameter.vendorExtensions);
+        postProcessEmitDefaultValue(parameter.vendorExtensions);
         super.postProcessParameter(parameter);
     }
 
     @Override
     public void postProcessModelProperty(CodegenModel model, CodegenProperty property) {
         postProcessPattern(property.pattern, property.vendorExtensions);
+        postProcessEmitDefaultValue(property.vendorExtensions);
         super.postProcessModelProperty(model, property);
     }
 
@@ -650,6 +666,10 @@ public class CSharpClientCodegen extends AbstractCSharpCodegen {
         }
     }
 
+    public void postProcessEmitDefaultValue(Map<String, Object> vendorExtensions) {
+        vendorExtensions.put("x-emit-default-value", optionalEmitDefaultValuesFlag);
+    }
+
     public void setTargetFramework(String dotnetFramework) {
         if (!frameworks.containsKey(dotnetFramework)) {
             LOGGER.warn("Invalid .NET framework version, defaulting to " + this.targetFramework);

modules/openapi-generator/src/main/resources/csharp/modelGeneric.mustache

@@ -31,7 +31,7 @@
         {{#description}}
         /// <value>{{description}}</value>
         {{/description}}
-        [DataMember(Name="{{baseName}}", EmitDefaultValue={{#isNullable}}true{{/isNullable}}{{^isNullable}}false{{/isNullable}})]
+        [DataMember(Name="{{baseName}}", EmitDefaultValue={{#vendorExtensions.x-emit-default-value}}true{{/vendorExtensions.x-emit-default-value}}{{^vendorExtensions.x-emit-default-value}}{{#isNullable}}true{{/isNullable}}{{^isNullable}}false{{/isNullable}}{{/vendorExtensions.x-emit-default-value}})]
         public {{#complexType}}{{{complexType}}}{{/complexType}}{{^complexType}}{{{datatypeWithEnum}}}{{/complexType}}{{^isContainer}}{{^required}}?{{/required}}{{/isContainer}} {{name}} { get; set; }
         {{/isEnum}}
         {{/vars}}
@@ -108,7 +108,7 @@ this.{{name}} = {{#lambda.camelcase_param}}{{name}}{{/lambda.camelcase_param}};
         /// {{^description}}Gets or Sets {{{name}}}{{/description}}{{#description}}{{description}}{{/description}}
         /// </summary>{{#description}}
         /// <value>{{description}}</value>{{/description}}
-        [DataMember(Name="{{baseName}}", EmitDefaultValue={{#isNullable}}true{{/isNullable}}{{^isNullable}}false{{/isNullable}})]{{#isDate}}
+        [DataMember(Name="{{baseName}}", EmitDefaultValue={{#vendorExtensions.x-emit-default-value}}true{{/vendorExtensions.x-emit-default-value}}{{^vendorExtensions.x-emit-default-value}}{{#isNullable}}true{{/isNullable}}{{^isNullable}}false{{/isNullable}}{{/vendorExtensions.x-emit-default-value}})]{{#isDate}}
         [JsonConverter(typeof(OpenAPIDateConverter))]{{/isDate}}
         public {{{dataType}}} {{name}} { get; {{#isReadOnly}}private {{/isReadOnly}}set; }
         {{/isEnum}}