rscg_Interface_to_null_object by Andrei Ignat

• NuGet / site data
• Details
  • Info
  • Original Readme
  • About
• How to use
  • Example (source csproj, source files)
  • Generated Files
• Useful
  • Download Example (.NET C#)
  • Share rscg_Interface_to_null_object
  • Category "Interface" has the following generators:
  • See category

NuGet / site data

Details

Info

info

Name: rscg_Interface_to_null_object

Interface to null object - common

Author: Andrei Ignat

NuGet: https://www.nuget.org/packages/rscg_Interface_to_null_object/

https://www.nuget.org/packages/rscg_Interface_to_null_object_common

You can find more details at https://github.com/ignatandrei/rscg_Interface_to_null_object/

Source: https://github.com/ignatandrei/rscg_Interface_to_null_object/

Original Readme

note

Interface to Null Object Pattern

Implementation of https://en.wikipedia.org/wiki/Null_object_pattern from interface

Installation

Add to your csproj file:

  <ItemGroup>
    <PackageReference Include="rscg_Interface_to_null_object" Version="2025.120.1832"  OutputItemType="Analyzer" ReferenceOutputAssembly="false"  />
    <PackageReference Include="rscg_Interface_to_null_object_common" Version="2025.120.1832" />
  </ItemGroup>
	<PropertyGroup>
		<EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
		<CompilerGeneratedFilesOutputPath>$(BaseIntermediateOutputPath)\GX</CompilerGeneratedFilesOutputPath>
	</PropertyGroup>

Or add the nuget packages rscg_Interface_to_null_object and rscg_Interface_to_null_object_common

Usage

[InterfaceToNullObject.ToNullObject]
public interface IEmployee
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public IDepartment Department { get; set; }
    public string GetFullName();
  
}

And then a C# class that implements the interface will be generated

public partial class Employee_null : global::IntegrationConsole.IEmployee
{

        public virtual string FirstName { get; set; } = default(string);
    
        public virtual string LastName { get; set; } = default(string);
    
        public virtual IntegrationConsole.IDepartment Department { get; set; } = default(IntegrationConsole.IDepartment);
    
        public virtual string GetFullName() { return default(string); }
    
}

About

note

Generate null objects for interfaces

How to use

Example (source csproj, source files)

CSharp Project

This is the CSharp Project that references rscg_Interface_to_null_object

<Project Sdk="Microsoft.NET.Sdk">

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net9.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>

  <ItemGroup>
    <PackageReference Include="rscg_Interface_to_null_object" Version="2025.120.1832" OutputItemType="Analyzer" ReferenceOutputAssembly="false"  />
    <PackageReference Include="rscg_Interface_to_null_object_common" Version="2025.120.1832" />
  </ItemGroup>

	<PropertyGroup>
		<EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
		<CompilerGeneratedFilesOutputPath>$(BaseIntermediateOutputPath)\GX</CompilerGeneratedFilesOutputPath>
	</PropertyGroup>
</Project>

Program.cs

This is the use of rscg_Interface_to_null_object in Program.cs

using NullInterface;

Console.WriteLine("Hello, World!");

Console.WriteLine("Hello, World!");
IDepartment department = new Department_null();
department.Name = "IT";
IEmployee employee = new Employee_null();
employee.FirstName = "Andrei";
employee.Department = department;
Console.WriteLine(employee.FirstName);
Console.WriteLine(employee.Department.Name);

IEmployee.cs

This is the use of rscg_Interface_to_null_object in IEmployee.cs

using InterfaceToNullObject;

namespace NullInterface;
[ToNullObject]
public interface IEmployee
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public IDepartment Department { get; set; }
    public string GetFullName();

    public string GetFullNameAndDepartment(string separator);
    public bool MoveEmployeeToDepartment(IDepartment department);

}

IDepartment.cs

This is the use of rscg_Interface_to_null_object in IDepartment.cs

namespace NullInterface;

using InterfaceToNullObject;

[ToNullObject]
public interface IDepartment
{
    public string Name { get; set; }
}

Generated Files

Those are taken from $(BaseIntermediateOutputPath)\GX

AutoInterfaceAttribute.g.cs

// <auto-generated/>
#pragma warning disable
#nullable enable annotations


#if !AUTOINTERFACE_EXCLUDE_ATTRIBUTES

using System;

namespace AutoInterfaceAttributes;

/// <summary>
/// Generates an interface for the decorated class/struct.
/// </summary>
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct, AllowMultiple = true)]
[System.CodeDom.Compiler.GeneratedCodeAttribute("AutoInterface", "2.4.0")]
internal sealed class AutoInterfaceAttribute : Attribute {
    /// <summary>
    /// <para>The name of the generated interface.</para>
    /// <para>Default is "I{ClassName}"</para>
    /// </summary>
    public string Name { get; init; }

    /// <summary>
    /// <para>The modifier(s) for the interface.</para>
    /// <para>Deault is "public partial"</para>
    /// </summary>
    public string Modifier { get; init; }

    /// <summary>
    /// <para>The namespace declaration for the interface.</para>
    /// <para>If empty string, no namespace directive will be used (global namespace).<br />
    /// Default (if not present) it will be mapped to the same namespace as the namespace of the class/struct.</para>
    /// </summary>
    public string Namespace { get; init; }

    /// <summary>
    /// <para>interface inheritance: Name(s) of interfaces this interface will inherit.</para>
    /// <para>Default is Array.Empty</para>
    /// </summary>
    public Type[] Inheritance { get; init; }

    /// <summary>
    /// <para>
    /// The Classes, structs or interfaces containing the generated interface.<br />
    /// e.g. ["public sealed partial class Example"] will wrap the interface with that expression.
    /// </para>
    /// <para>Default is Array.Empty</para>
    /// </summary>
    public string[] Nested { get; init; }

    /// <summary>
    /// <para>If enabled, static members get accepted and are generating "static abstract" members.</para>
    /// <para>Default is false</para>
    /// </summary>
    public bool StaticMembers { get; init; }
}

#endif

AutoInterfaceVisibilityInternalAttribute.g.cs

// <auto-generated/>
#pragma warning disable
#nullable enable annotations


#if !AUTOINTERFACE_EXCLUDE_ATTRIBUTES

using System;

namespace AutoInterfaceAttributes;

/// <summary>
/// Adds a "internal" access modifier to the interface member.
/// </summary>
[AttributeUsage(AttributeTargets.Property | AttributeTargets.Method | AttributeTargets.Event)]
[System.CodeDom.Compiler.GeneratedCodeAttribute("AutoInterface", "2.4.0")]
internal sealed class AutoInterfaceVisibilityInternal : Attribute { }

#endif

AutoInterfaceVisibilityPrivateProtectedAttribute.g.cs

// <auto-generated/>
#pragma warning disable
#nullable enable annotations


#if !AUTOINTERFACE_EXCLUDE_ATTRIBUTES

using System;

namespace AutoInterfaceAttributes;

/// <summary>
/// Adds a "private protected" access modifier to the interface member.
/// </summary>
[AttributeUsage(AttributeTargets.Property | AttributeTargets.Method | AttributeTargets.Event)]
[System.CodeDom.Compiler.GeneratedCodeAttribute("AutoInterface", "2.4.0")]
internal sealed class AutoInterfaceVisibilityPrivateProtected : Attribute { }

#endif

AutoInterfaceVisibilityProtectedAttribute.g.cs

// <auto-generated/>
#pragma warning disable
#nullable enable annotations


#if !AUTOINTERFACE_EXCLUDE_ATTRIBUTES

using System;

namespace AutoInterfaceAttributes;

/// <summary>
/// Adds a "protected" access modifier to the interface member.
/// </summary>
[AttributeUsage(AttributeTargets.Property | AttributeTargets.Method | AttributeTargets.Event)]
[System.CodeDom.Compiler.GeneratedCodeAttribute("AutoInterface", "2.4.0")]
internal sealed class AutoInterfaceVisibilityProtected : Attribute { }

#endif

AutoInterfaceVisibilityProtectedInternalAttribute.g.cs

// <auto-generated/>
#pragma warning disable
#nullable enable annotations


#if !AUTOINTERFACE_EXCLUDE_ATTRIBUTES

using System;

namespace AutoInterfaceAttributes;

/// <summary>
/// Adds a "protected internal" access modifier to the interface member.
/// </summary>
[AttributeUsage(AttributeTargets.Property | AttributeTargets.Method | AttributeTargets.Event)]
[System.CodeDom.Compiler.GeneratedCodeAttribute("AutoInterface", "2.4.0")]
internal sealed class AutoInterfaceVisibilityProtectedInternal : Attribute { }

#endif

AutoInterfaceVisibilityPublicAttribute.g.cs

// <auto-generated/>
#pragma warning disable
#nullable enable annotations


#if !AUTOINTERFACE_EXCLUDE_ATTRIBUTES

using System;

namespace AutoInterfaceAttributes;

/// <summary>
/// Adds a "public" access modifier to the interface member.
/// </summary>
[AttributeUsage(AttributeTargets.Property | AttributeTargets.Method | AttributeTargets.Event)]
[System.CodeDom.Compiler.GeneratedCodeAttribute("AutoInterface", "2.4.0")]
internal sealed class AutoInterfaceVisibilityPublic : Attribute { }

#endif

IDepartment_NullInterface.Department_IDepartment.cs.g.cs

// <auto-generated/>
#pragma warning disable
#nullable enable annotations




namespace NullInterface;

public partial interface IDepartment {
    string Name { get; set; }
}

IEmployee_NullInterface.Employee_Employee.cs.g.cs

// <auto-generated/>
#pragma warning disable
#nullable enable annotations


using AutoInterfaceAttributes;

namespace NullInterface;

public partial interface IEmployee {
    string FirstName { get; set; }

    string LastName { get; set; }

    IDepartment Department { get; set; }

    string GetFullName();

    string GetFullNameAndDepartment(string separator);
}

IgnoreAutoInterfaceAttribute.g.cs

// <auto-generated/>
#pragma warning disable
#nullable enable annotations


#if !AUTOINTERFACE_EXCLUDE_ATTRIBUTES

using System;

namespace AutoInterfaceAttributes;

/// <summary>
/// The decorated member will be Ignored by the generator.
/// </summary>
[AttributeUsage(AttributeTargets.Property | AttributeTargets.Method | AttributeTargets.Event)]
[System.CodeDom.Compiler.GeneratedCodeAttribute("AutoInterface", "2.4.0")]
internal sealed class IgnoreAutoInterfaceAttribute : Attribute { }

#endif

Useful

Download Example (.NET C#)

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Download Example project rscg_Interface_to_null_object

Share rscg_Interface_to_null_object

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https://ignatandrei.github.io/RSCG_Examples/v2/docs/rscg_Interface_to_null_object

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Category "Interface" has the following generators:

1 AutoInterface

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7 Minerals.AutoInterfaces

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12 rscg_Interface_to_null_object

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14 ShadowWriterNullobjects

See category

Interface