README.md

MMLib.ToString

This is my first attempt with a C# Source generators.

How to install

dotnet add package MMLib.ToString.Generator

Motivation

We all love the new record type. One of the completely marginal features is that it has an override ToString() method.

public record Person(int Id, string Name);

Person person = new (2, "Milan");

Console.WriteLine(person); //Output: Person {Id = 2, Name = Milan}

Why don't standard classes have such an output? Why do I have to implement this over and over again in each class? How many times have you override a standard ToString for debug purpouse?

I decided to try the source generator to allow it to generate a similar override for all classes marked with my attribute (I want to use the Source generators for other purposes, this came to me as a nice example to try 😉)

Examples

[ToString()]
public partial class Person
{
    public int Id { get; set; }

    public string Name { get; set; }

    public Foo Foo { get; set; } = new Foo()
    {
        Id = 1,
        Bar = "bar",
        Created = DateTime.Now,
        Name = "somebody"
    };
}

[ToString()]
public partial class Foo
{
    public int Id { get; set; }

    public string Bar { get; set; }

    public string Name { get; set; }

    public DateTime Created { get; set; }
}

var p = new Person() { Id = 1, Name = "Nobody" };
Console.WriteLine(p); 
//Output:
//Person {Id = 1, Name = Nobody, Foo = Foo {Id = 1, Bar = bar, Name = somebody, Created = 24. 4. 2021 20:39:04}}

Customizations

This attribute DisplayCollections can be used to control the behavior of the ToString() method when it is called on collection types that implement IEnumerable interface.

When the value of the DisplayCollections attribute is set to true, ToString() method will return a string representation of the collection's elements, separated by a comma. This allows for easy visualization of the contents of the collection.

If the DisplayCollections attribute is not specified, or if its value is set to false, ToString() method will return the name of type of the collection. This is the default behavior.

How to activate

Just do two things. Mark your class as partial and add my attribute [ToString].