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Support parameter-less event methods in DataContractSerializer (without a StreamingContext parameter) #109264

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#125922
Open
Support parameter-less event methods in DataContractSerializer (without a StreamingContext parameter)#109264
#125922
Labels
area-Serializationbinaryformatter-migrationIssues related to the removal of BinaryFormatter and migrations away from it
Milestone
Future

Description

@Takym
Takym
opened on Oct 27, 2024

When I use event methods for the DataContractSerializer system, I still need a StreamingContext parameter even though the BinaryFormatter stuff is deprecated. The constructor and state property of StreamingContext is marked as obsolete.

The StreamingContext _ parameter is unused in the below code. I feel it is redundant.

[OnSerializing()]
void OnSerializing(StreamingContext _) { ... }

[OnSerialized()]
void OnSerializing(StreamingContext _) { ... }

[OnDeserializing()]
void OnSerializing(StreamingContext _) { ... }

[OnDeserialized()]
void OnSerializing(StreamingContext _) { ... }

Parameter-less one like the code below makes me feel refreshed. Also, we do not need to type unused parameters. So, developing efficiency is more improved. In addition, maybe, passing (copying structure data) the parameter makes a program slow. Or maybe, the speed is the same because of checking parameters.

[OnSerializing()]
void OnSerializing() { ... }

[OnSerialized()]
void OnSerializing() { ... }

[OnDeserializing()]
void OnSerializing() { ... }

[OnDeserialized()]
void OnSerializing() { ... }

I agree that we should still support with StreamingContext _ parameter for compatibility but I want a parameter-less option.

Activity

  1. ghost added
    area-System.Text.Json
    on Oct 27, 2024
  2. dotnet-policy-service
    added
    untriagedNew issue has not been triaged by the area owner
    on Oct 27, 2024

  3. dotnet-policy-service commented on Oct 27, 2024

    @dotnet-policy-service
    dotnet-policy-serviceBot
    on Oct 27, 2024 – with Dotnet Policy Service
    Contributor

    Tagging subscribers to this area: @dotnet/area-system-text-json, @gregsdennis
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  4. teo-tsirpanis
    added
    area-Serialization
    and removed
    area-System.Text.Json
    on Oct 28, 2024

  5. Takym commented on Nov 23, 2024

    @Takym
    Takym
    on Nov 23, 2024
    ContributorAuthor
    Related codes

    runtime/src/libraries/System.Private.DataContractSerialization/src/System/Runtime/Serialization/ClassDataContract.cs

    Lines 1063 to 1142 in f1332ab

    internal void EnsureMethodsImported()
    {
    if (!_isMethodChecked && UnderlyingType != null)
    {
    lock (this)
    {
    if (!_isMethodChecked)
    {
    Type type = UnderlyingType;
    MethodInfo[] methods = type.GetMethods(BindingFlags.DeclaredOnly | BindingFlags.Instance | BindingFlags.Public | BindingFlags.NonPublic);
    for (int i = 0; i < methods.Length; i++)
    {
    MethodInfo method = methods[i];
    Type? prevAttributeType = null;
    ParameterInfo[] parameters = method.GetParameters();
    if (HasExtensionData && IsValidExtensionDataSetMethod(method, parameters))
    {
    if (method.Name == Globals.ExtensionDataSetExplicitMethod || !method.IsPublic)
    _extensionDataSetMethod = XmlFormatGeneratorStatics.ExtensionDataSetExplicitMethodInfo;
    else
    _extensionDataSetMethod = method;
    }
    if (IsValidCallback(method, parameters, Globals.TypeOfOnSerializingAttribute, _onSerializing, ref prevAttributeType))
    _onSerializing = method;
    if (IsValidCallback(method, parameters, Globals.TypeOfOnSerializedAttribute, _onSerialized, ref prevAttributeType))
    _onSerialized = method;
    if (IsValidCallback(method, parameters, Globals.TypeOfOnDeserializingAttribute, _onDeserializing, ref prevAttributeType))
    _onDeserializing = method;
    if (IsValidCallback(method, parameters, Globals.TypeOfOnDeserializedAttribute, _onDeserialized, ref prevAttributeType))
    _onDeserialized = method;
    }
    Interlocked.MemoryBarrier();
    _isMethodChecked = true;
    }
    }
    }
    }
    private bool IsValidExtensionDataSetMethod(MethodInfo method, ParameterInfo[] parameters)
    {
    if (method.Name == Globals.ExtensionDataSetExplicitMethod || method.Name == Globals.ExtensionDataSetMethod)
    {
    Debug.Assert(method.DeclaringType != null);
    if (_extensionDataSetMethod != null)
    ThrowInvalidDataContractException(SR.Format(SR.DuplicateExtensionDataSetMethod, method, _extensionDataSetMethod, DataContract.GetClrTypeFullName(method.DeclaringType)));
    if (method.ReturnType != Globals.TypeOfVoid)
    DataContract.ThrowInvalidDataContractException(SR.Format(SR.ExtensionDataSetMustReturnVoid, DataContract.GetClrTypeFullName(method.DeclaringType), method), method.DeclaringType);
    if (parameters == null || parameters.Length != 1 || parameters[0].ParameterType != Globals.TypeOfExtensionDataObject)
    DataContract.ThrowInvalidDataContractException(SR.Format(SR.ExtensionDataSetParameterInvalid, DataContract.GetClrTypeFullName(method.DeclaringType), method, Globals.TypeOfExtensionDataObject), method.DeclaringType);
    return true;
    }
    return false;
    }
    private static bool IsValidCallback(MethodInfo method, ParameterInfo[] parameters, Type attributeType, MethodInfo? currentCallback, ref Type? prevAttributeType)
    {
    if (method.IsDefined(attributeType, false))
    {
    Debug.Assert(method.DeclaringType != null);
    if (currentCallback != null)
    DataContract.ThrowInvalidDataContractException(SR.Format(SR.DuplicateCallback, method, currentCallback, DataContract.GetClrTypeFullName(method.DeclaringType), attributeType), method.DeclaringType);
    else if (prevAttributeType != null)
    DataContract.ThrowInvalidDataContractException(SR.Format(SR.DuplicateAttribute, prevAttributeType, attributeType, DataContract.GetClrTypeFullName(method.DeclaringType), method), method.DeclaringType);
    else if (method.IsVirtual)
    DataContract.ThrowInvalidDataContractException(SR.Format(SR.CallbacksCannotBeVirtualMethods, method, DataContract.GetClrTypeFullName(method.DeclaringType), attributeType), method.DeclaringType);
    else
    {
    if (method.ReturnType != Globals.TypeOfVoid)
    DataContract.ThrowInvalidDataContractException(SR.Format(SR.CallbackMustReturnVoid, DataContract.GetClrTypeFullName(method.DeclaringType), method), method.DeclaringType);
    if (parameters == null || parameters.Length != 1 || parameters[0].ParameterType != Globals.TypeOfStreamingContext)
    DataContract.ThrowInvalidDataContractException(SR.Format(SR.CallbackParameterInvalid, DataContract.GetClrTypeFullName(method.DeclaringType), method, Globals.TypeOfStreamingContext), method.DeclaringType);
    prevAttributeType = attributeType;
    }
    return true;
    }
    return false;
    }

    runtime/src/libraries/System.Private.DataContractSerialization/src/System/Runtime/Serialization/ReflectionClassWriter.cs

    Lines 130 to 150 in f1332ab

    private static void InvokeOnSerializing(object obj, XmlObjectSerializerWriteContext context, ClassDataContract classContract)
    {
    if (classContract.BaseClassContract != null)
    InvokeOnSerializing(obj, context, classContract.BaseClassContract);
    if (classContract.OnSerializing != null)
    {
    var contextArg = context.GetStreamingContext();
    classContract.OnSerializing.Invoke(obj, new object[] { contextArg });
    }
    }
    private static void InvokeOnSerialized(object obj, XmlObjectSerializerWriteContext context, ClassDataContract classContract)
    {
    if (classContract.BaseClassContract != null)
    InvokeOnSerialized(obj, context, classContract.BaseClassContract);
    if (classContract.OnSerialized != null)
    {
    var contextArg = context.GetStreamingContext();
    classContract.OnSerialized.Invoke(obj, new object[] { contextArg });
    }
    }

    runtime/src/libraries/System.Private.DataContractSerialization/src/System/Runtime/Serialization/Json/JsonFormatWriterGenerator.cs

    Lines 174 to 198 in f1332ab

    private void InvokeOnSerializing(ClassDataContract classContract)
    {
    if (classContract.BaseClassContract != null)
    InvokeOnSerializing(classContract.BaseClassContract);
    if (classContract.OnSerializing != null)
    {
    _ilg.LoadAddress(_objectLocal);
    _ilg.Load(_contextArg);
    _ilg.Call(XmlFormatGeneratorStatics.GetStreamingContextMethod);
    _ilg.Call(classContract.OnSerializing);
    }
    }
    private void InvokeOnSerialized(ClassDataContract classContract)
    {
    if (classContract.BaseClassContract != null)
    InvokeOnSerialized(classContract.BaseClassContract);
    if (classContract.OnSerialized != null)
    {
    _ilg.LoadAddress(_objectLocal);
    _ilg.Load(_contextArg);
    _ilg.Call(XmlFormatGeneratorStatics.GetStreamingContextMethod);
    _ilg.Call(classContract.OnSerialized);
    }
    }

    runtime/src/libraries/System.Private.DataContractSerialization/src/System/Runtime/Serialization/XmlFormatWriterGenerator.cs

    Lines 207 to 231 in f1332ab

    private void InvokeOnSerializing(ClassDataContract classContract)
    {
    if (classContract.BaseClassContract != null)
    InvokeOnSerializing(classContract.BaseClassContract);
    if (classContract.OnSerializing != null)
    {
    _ilg.LoadAddress(_objectLocal);
    _ilg.Load(_contextArg);
    _ilg.Call(XmlFormatGeneratorStatics.GetStreamingContextMethod);
    _ilg.Call(classContract.OnSerializing);
    }
    }
    private void InvokeOnSerialized(ClassDataContract classContract)
    {
    if (classContract.BaseClassContract != null)
    InvokeOnSerialized(classContract.BaseClassContract);
    if (classContract.OnSerialized != null)
    {
    _ilg.LoadAddress(_objectLocal);
    _ilg.Load(_contextArg);
    _ilg.Call(XmlFormatGeneratorStatics.GetStreamingContextMethod);
    _ilg.Call(classContract.OnSerialized);
    }
    }

    runtime/src/libraries/System.Private.DataContractSerialization/src/System/Runtime/Serialization/ReflectionReader.cs

    Lines 398 to 418 in f1332ab

    private static void InvokeOnDeserializing(XmlObjectSerializerReadContext context, ClassDataContract classContract, object obj)
    {
    if (classContract.BaseClassContract != null)
    InvokeOnDeserializing(context, classContract.BaseClassContract, obj);
    if (classContract.OnDeserializing != null)
    {
    var contextArg = context.GetStreamingContext();
    classContract.OnDeserializing.Invoke(obj, new object[] { contextArg });
    }
    }
    private static void InvokeOnDeserialized(XmlObjectSerializerReadContext context, ClassDataContract classContract, object obj)
    {
    if (classContract.BaseClassContract != null)
    InvokeOnDeserialized(context, classContract.BaseClassContract, obj);
    if (classContract.OnDeserialized != null)
    {
    var contextArg = context.GetStreamingContext();
    classContract.OnDeserialized.Invoke(obj, new object[] { contextArg });
    }
    }

    runtime/src/libraries/System.Private.DataContractSerialization/src/System/Runtime/Serialization/XmlFormatReaderGenerator.cs

    Lines 290 to 322 in f1332ab

    private void InvokeOnDeserializing(ClassDataContract classContract)
    {
    Debug.Assert(_objectLocal != null);
    Debug.Assert(_objectType != null);
    if (classContract.BaseClassContract != null)
    InvokeOnDeserializing(classContract.BaseClassContract);
    if (classContract.OnDeserializing != null)
    {
    _ilg.LoadAddress(_objectLocal);
    _ilg.ConvertAddress(_objectLocal.LocalType, _objectType);
    _ilg.Load(_contextArg);
    _ilg.LoadMember(XmlFormatGeneratorStatics.GetStreamingContextMethod);
    _ilg.Call(classContract.OnDeserializing);
    }
    }
    private void InvokeOnDeserialized(ClassDataContract classContract)
    {
    Debug.Assert(_objectLocal != null);
    Debug.Assert(_objectType != null);
    if (classContract.BaseClassContract != null)
    InvokeOnDeserialized(classContract.BaseClassContract);
    if (classContract.OnDeserialized != null)
    {
    _ilg.LoadAddress(_objectLocal);
    _ilg.ConvertAddress(_objectLocal.LocalType, _objectType);
    _ilg.Load(_contextArg);
    _ilg.LoadMember(XmlFormatGeneratorStatics.GetStreamingContextMethod);
    _ilg.Call(classContract.OnDeserialized);
    }
    }

    runtime/src/libraries/System.Private.DataContractSerialization/src/System/Runtime/Serialization/Json/JsonFormatReaderGenerator.cs

    Lines 232 to 258 in f1332ab

    private void InvokeOnDeserializing(ClassDataContract classContract)
    {
    if (classContract.BaseClassContract != null)
    InvokeOnDeserializing(classContract.BaseClassContract);
    if (classContract.OnDeserializing != null)
    {
    _ilg.LoadAddress(_objectLocal);
    _ilg.ConvertAddress(_objectLocal.LocalType, _objectType!);
    _ilg.Load(_contextArg);
    _ilg.LoadMember(XmlFormatGeneratorStatics.GetStreamingContextMethod);
    _ilg.Call(classContract.OnDeserializing);
    }
    }
    private void InvokeOnDeserialized(ClassDataContract classContract)
    {
    if (classContract.BaseClassContract != null)
    InvokeOnDeserialized(classContract.BaseClassContract);
    if (classContract.OnDeserialized != null)
    {
    _ilg.LoadAddress(_objectLocal);
    _ilg.ConvertAddress(_objectLocal.LocalType, _objectType!);
    _ilg.Load(_contextArg);
    _ilg.LoadMember(XmlFormatGeneratorStatics.GetStreamingContextMethod);
    _ilg.Call(classContract.OnDeserialized);
    }
    }

  6. jeffhandley
    added
    binaryformatter-migrationIssues related to the removal of BinaryFormatter and migrations away from it
    on Feb 2, 2025

  7. dotnet-policy-service commented on Feb 2, 2025

    @dotnet-policy-service
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    on Feb 2, 2025 – with Dotnet Policy Service
    Contributor

    Tagging subscribers to 'binaryformatter-migration': @adamsitnik, @bartonjs, @jeffhandley, @terrajobst

  8. StephenMolloy
    added this to the Future milestone on Aug 3, 2025
  9. jeffschwMSFT
    removed
    untriagedNew issue has not been triaged by the area owner
    on Aug 4, 2025
  10. Takym
    added a commit that references this issue on Mar 22, 2026

    Resolves dotnet#109264: Implementation to support parameter-less even…

    61e76b2
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