EdlinSoftware.Generators.ReadOnlyInterface 1.0.1

Read-only interface generator

This repository contains Roslyn generator of read-only interfaces.

Russian version of documentation

Installation

Add EdlinSoftware.Generators.ReadOnlyInterface NuGet package to your project:

dotnet add package EdlinSoftware.Generators.ReadOnlyInterface

Generation of read-only interface

If you want to generate a read-only interface for your type, you must do the following things:

• Make your type partial,
• Augment it with WithReadOnly attribute from EdlinSoftware.Generators.ReadOnlyInterface namespace.

using EdlinSoftware.Generators.ReadOnlyInterface;

[WithReadOnly]
internal partial class SimpleClass
{
    public long Id { get; set; }

    public string Name { get; set; } = string.Empty;

    public DateTime BirthDate { get; set; }

    public List<string> Hobbies { get; set; } = new();
}

Properties of generated read-only interface

The generated interface will contain all public readable properties of your type, including inherited properties from base types.

Supported types

You can generate read-only interface for:

• Classes
• Structures
• Records
• Interfaces

[WithReadOnly]
internal partial struct SimpleStruct
{
    public long Id { get; set; }

    public string Name { get; set; }
}

Nested types

You can generate read-only interface for a nested type. But in this case you must make partial not only the type itself, but all containing types:

internal partial class Container
{
    [WithReadOnly]
    private partial class Nested
    {
        public long Id { get; set; }
    }
}

Type accessibility

Read-only interface can be generated for a type of any accessibility:

• public
• protected
• internal
• protected internal
• private

By default, generated read-only interface has the same accessibility as its underlying type.

But you also may change accessibility of generated read-only interface. It can be done using Accessibility property of WithReadOnly attribute:

partial class AccessibilityContainer
{
    [WithReadOnly(Accessibility = ReadOnlyInterfaceAccessibility.Public)]
    private partial record PublicAccessibility(long Id);
}

As new read-only interface will be generated inside the same containing type, as your underlying type, it is your responsibility to provide valid interface accessibility for this place.

Name of read-only interface

By default the name of a read-only interface is generated from the name of underlying type by adding ReadOnly prefix. For example, for a class with name Person there will be generated a read-only interface with name IReadOnlyPerson. For an interface with name IEntity there will be generated a read-only interface with name IReadOnlyEntity.

But you have an ability to change this prefix. It can be done using Prefix property of WithReadOnly attribute:

[WithReadOnly(Prefix = "IFrozen")]
partial class PrefixedClass
{
    public string Name { get; set; } = string.Empty;
}

In this case, you are fully responsible for providing a prefix which forms a valid .NET name of type.

Types of properties of read-only interface

Usually types of properties of the read only interface are the same as in the initial class. But there can be a case, when such type has read-only interface itself:

[WithReadOnly]
public partial class EntityClass
{
    public long Id { get; set; }
}

[WithReadOnly]
public partial class AnotherClass
{
    public EntityClass Entity { get; set; }
}

Here Entity property of AnotherClass has type EntityClass which itself has read-only interface. In this case, generated interface will change type of this property to corresponding read-only interface:

public partial interface IReadOnlyAnotherClass
{
    IReadOnlyEntityClass Entity { get; }
}

If you don't want such behavior, you can use NotReplaceWithReadOnly attribute:

[WithReadOnly]
public partial class AnotherClass
{
    [NotReplaceWithReadOnly]
    public EntityClass Entity { get; set; }

You can set this attribute to particular properties or to the whole type:

[WithReadOnly]
[NotReplaceWithReadOnly]
public partial class AnotherClass
{
    public EntityClass Entity { get; set; }
}

Appreciations

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