RSCG – DecoratorGenerator

RSCG – DecoratorGenerator
 
 

adding decorator for classes/ interfaces

This is how you can use DecoratorGenerator .

The code that you start with is

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

  <PropertyGroup>
    <OutputType>Exe</OutputType>
    <TargetFramework>net10.0</TargetFramework>
    <ImplicitUsings>enable</ImplicitUsings>
    <Nullable>enable</Nullable>
  </PropertyGroup>
	<PropertyGroup>
		<EmitCompilerGeneratedFiles>true</EmitCompilerGeneratedFiles>
		<CompilerGeneratedFilesOutputPath>$(BaseIntermediateOutputPath)\GX</CompilerGeneratedFilesOutputPath>
	</PropertyGroup>
	<ItemGroup>
	  <PackageReference Include="DecoratorGenerator" Version="0.3.0" />
	</ItemGroup>
</Project>

The code that you will use is

// See https://aka.ms/new-console-template for more information
using DecoratorDemo;

Console.WriteLine("Hello, World!");
IPerson person = new Person();
person = new LogPerson(person);
person.FirstName = "Andrei";
person.LastName = "Ignat";
Console.WriteLine(person.FullName());
var birthDate = new DateTime(1970, 4, 16);
var age = await person.CalculateAgeAsync(birthDate);
Console.WriteLine($"Age is {age}");

using System;
using System.Collections.Generic;
using System.Text;

namespace DecoratorDemo;

internal class Person : IPerson
{
    public string FirstName { get; set; } = string.Empty;
    public string LastName { get; set; } = string.Empty;
    public string FullName()
    {
        return $"{FirstName} {LastName}";
    }
    public async Task<int> CalculateAgeAsync(DateTime birthDate)
    {
        await Task.Delay(100); // Simulate async work
        var today = DateTime.Today;
        var age = today.Year - birthDate.Year;
        if (birthDate.Date > today.AddYears(-age)) age--;
        return age;
    }

}

using DecoratorGenerator;
using System;
using System.Collections.Generic;
using System.Text;

namespace DecoratorDemo;

[Decorate]
public interface IPerson
{
    public string FirstName { get; set; }
    public string LastName { get; set; }
    public string FullName();

    public Task<int> CalculateAgeAsync(DateTime birthDate);
}

using System;
using System.Collections.Generic;
using System.Text;

namespace DecoratorDemo;

internal class LogPerson : PersonDecorator
{
    public LogPerson(IPerson person) : base(person)
    {
    }
    public override string FirstName
    {
        get
        {
            Console.WriteLine($"FirstName getter called, returning {base.FirstName}");
            return base.FirstName;
        }
        set
        {
            Console.WriteLine($"FirstName setter called, setting value to {value}");
            base.FirstName = value;
        }
    }
    public override string FullName()
    {
        Console.WriteLine($"FullName() called for {FirstName} {LastName}" );
        return base.FullName();
    }
    public override async Task<int> CalculateAgeAsync(DateTime birthDate)
    {
        Console.WriteLine($"CalculateAgeAsync called with birthDate: {birthDate.ToShortDateString()}");
        return await base.CalculateAgeAsync(birthDate);
    }
}

The code that is generated is

// <auto-generated/>
#nullable restore
namespace DecoratorDemo;

public abstract class PersonDecorator : IPerson
{
    private IPerson person;

    protected PersonDecorator(IPerson person) {
        this.person = person;
    }

    public virtual string FirstName { get => person.FirstName; set => person.FirstName = value; }

    public virtual string LastName { get => person.LastName; set => person.LastName = value; }

    public virtual string FullName() {
        return person.FullName();
    }

    public virtual System.Threading.Tasks.Task<int> CalculateAgeAsync(System.DateTime birthDate) {
        return person.CalculateAgeAsync(birthDate);
    }
}

Code and pdf at

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