https://github.com/Youssef1313/PrintMembersGenerator

A source generator that helps re-defining C# record's PrintMembers method to force include/exclude certain members.
https://github.com/Youssef1313/PrintMembersGenerator

csharp csharp-sourcegenerator printmembers records source-generators

Last synced: 3 months ago
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A source generator that helps re-defining C# record's PrintMembers method to force include/exclude certain members.

• Host: GitHub
• URL: https://github.com/Youssef1313/PrintMembersGenerator
• Owner: Youssef1313
• Created: 2020-09-24T21:37:42.000Z (about 4 years ago)
• Default Branch: master
• Last Pushed: 2020-09-25T21:59:54.000Z (about 4 years ago)
• Last Synced: 2024-05-01T16:27:24.717Z (6 months ago)
• Topics: csharp, csharp-sourcegenerator, printmembers, records, source-generators
• Language: C#
• Homepage:
• Size: 35.2 KB
• Stars: 5
• Watchers: 3
• Forks: 0
• Open Issues: 3
• Metadata Files:
  • Readme: README.md

Awesome Lists containing this project

• RSCG_Examples - PrintMembersGenerator
• csharp-source-generators - PrintMembersGenerator -   helps re-defining C# record's PrintMembers method to force include/exclude certain members. (Source Generators / Other)

README

        
# PrintMembersGenerator

A source generator that helps re-defining C# record's PrintMembers method to force include/exclude certain members.

This project is related to [dotnet/csharplang#3925](https://github.com/dotnet/csharplang/issues/3925).

For more information about source generators, see [Introducing C# source generators blog](https://devblogs.microsoft.com/dotnet/introducing-c-source-generators/).

## Overview

C# 9.0 introduced a new language feature called [Records](https://docs.microsoft.com/dotnet/csharp/language-reference/proposals/csharp-9.0/records). A record is simply a reference type with some compiler-generated (synthesized) methods.

The interest of this project is on `PrintMembers` method, which the compiler uses when you call `.ToString()` on a record.

The compiler only includes all public non-override instance fields/properties in `PrintMembers`, and allows you to re-define PrintMembers if the provided implementation doesn't suite your need.

This source generator makes it easier to force-include or force-exclude certain record members in `PrintMembers` implementation through a provided attribute.

## How to use

### Add reference to the generator

Currently, this is not packed into a NuGet package. So you'll have to clone the source code, and add a reference to the *PrintMembersSourceGenerators.csproj*. The added reference should look like the following:

```xml

  

    

  

```

### Use the attribute

First of all, here is the internal definition of the attribute:

```csharp

namespace SourceGenerator

{

    [AttributeUsage(AttributeTargets.Field | AttributeTargets.Property, AllowMultiple = false, Inherited = false)]

    public sealed class PrintMembersAttribute : Attribute

    {

        public bool ShouldInclude { get; set; } = true;

    }

}

```

As you see, the attribute can only be applied to fields and properties.

- To force-include a member in `PrintMembers`, you should either use `[PrintMembers]` or `[PrintMembers(ShouldInclude = true)]`.

- To force-exclude a member in `PrintMembers`, you should use `[PrintMembers(ShouldInclude = false)]`.

Currently, positional record parameters are not supported. Support for them should be added soon through targeted attributes:

```csharp

[property: PrintMembers(ShouldInclude = false)]

```

See [this comment on dotnet/csharplang#3644](https://github.com/dotnet/csharplang/issues/3644#issuecomment-692742525).

## Notes

1. If the semantics of the added attribute is the **same** as what the compiler does, the generator ignores the attribute.

2. The record **must** be partial to allow the source generator to re-define `PrintMembers`.