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CSharp.SourceGenerators.Extensions
See this page.
FluentBuilder
A project which uses Source Generation to create a FluentBuilder for a specified model or DTO.
This project is based on Tom Phan : "auto-generate-builders-using-source-generator-in-net-5".
Install
You can install from NuGet using the following command in the package manager window:
Install-Package FluentBuilder
Or via the Visual Studio NuGet package manager or if you use the dotnet command:
dotnet add package FluentBuilder
1️⃣ Usage on a existing class
Annotate a class
Annotate an existing class with [FluentBuilder.AutoGenerateBuilder] to indicate that a FluentBuilder should be generated for this class:
using FluentBuilder;
[AutoGenerateBuilder]
public class User
{
public string FirstName { get; set; }
public string LastName { get; set; }
public DateTime? Date { get; set; }
[FluentBuilderIgnore] // Add this attribute to ignore this property when generating a FluentBuilder.
public int Age { get; set; }
public int Answer { get; set; } = 42; // When a default value is set, this value is also set as default in the FluentBuilder.
}AutoGenerateBuilder - attribute
This attribute has 4 arguments:
- type (Type): The type for which to create the builder, see 'Define a class which needs to act as a builder'
- handleBaseClasses (bool): Handle also base-classes. Default value is
true. - accessibility (enum FluentBuilderAccessibility): Generate builder methods for
PublicorPublicAndPrivate. Default value when not provided isPublic. - methods (enum FluentBuilderMethods): Generate
With***methods or alsoWithout***methods. Default value when not provided isWithOnly. See also Notes
Use FluentBuilder
using System;
using FluentBuilder;
namespace Test;
class Program
{
static void Main(string[] args)
{
var user = new UserBuilder()
.WithFirstName("Test")
.WithLastName("User")
.Build();
Console.WriteLine($"{user.FirstName} {user.LastName}");
}
}Use FluentBuilder when the class has a default (parameter-less) constructor
using FluentBuilder;
[AutoGenerateBuilder]
public class User
{
public string FirstName { get; set; }
public string LastName { get; set; }
public DateTime? Date { get; set; }
public User()
{
FirstName = "test";
}
}using System;
using FluentBuilder;
namespace Test;
class Program
{
static void Main(string[] args)
{
var user = new UserBuilder()
.WithLastName("User")
.Build(false); // ⭐ Provide `false` for `useObjectInitializer` here.
Console.WriteLine($"{user.FirstName} {user.LastName}");
}
}Use FluentBuilder when the class has a constructor with parameters
using FluentBuilder;
[AutoGenerateBuilder]
public class User
{
public string FirstName { get; set; }
public string LastName { get; set; }
public DateTime? Date { get; set; }
public User(string first)
{
FirstName = first;
}
}using System;
using FluentBuilder;
namespace Test;
class Program
{
static void Main(string[] args)
{
var user = new UserBuilder()
.UsingConstructor("First") // ⭐ Use `UsingConstructor` here.
.WithLastName("User")
.Build();
Console.WriteLine($"{user.FirstName} {user.LastName}");
}
}Using FluentBuilder when a class has an Array or IEnumerable<T> property
using FluentBuilder;
[AutoGenerateBuilder]
public class UserDto
{
public IEnumerable<EmailDto> SecondaryEmails { get; set; }
public int[] IntArray { get; set; }
}var user = new UserDtoBuilder()
.WithIntArray(ib => ib // 👈 Use a Integer Array Builder
.Add(1) // Add a normal integer
.Add(() => 2) // Add an integer with a Func<>
.Build()
)
.WithSecondaryEmails(sb => sb // 👈 Use a EmailDto IEnumerable Builder
.Add(new EmailDto()) // Add a normal EmailDto using new() constructor
.Add(() => new EmailDto()) // Add an EmailDto using Func<>
.Add(eb => eb // 👈 Use a EmailDto IEnumerable Builder to add an EmailDto
.WithPrimary(true)
.Build()
)
.Build()
)
.Build();Using FluentBuilder when a class has an IDictionary<TKey, TValue> property
using FluentBuilder;
[AutoGenerateBuilder]
public class UserDto
{
public IDictionary<string, int> Tags { get; set; }
}var user = new UserDtoBuilder()
.WithTags(db => db // 👈 Use a Dictionary<TKey, TValue> Builder
.Add("test", 123) // Add a key with value
.Add(() => new KeyValuePair<string, int>("x", 42)) // Add a KeyValuePair with a Func<>
.Build()
)
.Build();2️⃣ Define a class which needs to act as a builder
This scenario is very usefull when you cannot modify the class to annotate it.
Create a public and partial builder class
And annotate this class with [AutoGenerateBuilder(typeof(XXX))] where XXX is the type for which you want to generate a FluentBuilder.
using FluentBuilder;
[AutoGenerateBuilder(typeof(UserDto))]
public partial class MyUserDtoBuilder
{
}Use FluentBuilder
using System;
using FluentBuilder;
namespace Test;
class Program
{
static void Main(string[] args)
{
var user = new MyUserDtoBuilder() // 👈 Just use your own Builder
.WithFirstName("Test")
.WithLastName("User")
.Build();
Console.WriteLine($"{user.FirstName} {user.LastName}");
}
}Extension Method
By default, the AsBuilder extension method is also generated which allows you to change an existing instance using the With-methods from the builder.
Example:
var user = await dbContext.Users.FirstAsync();
user = user.AsBuilder() // Lifts the user into a builder instance
.WithLastName("Different LastName") // Updates "LastName" while keeping existing properties
.Build(); // Changes are applied
await dbContext.SaveChangesAsync(); // User's LastName property is updated.Notes
Since version 0.8.0, this FluentBuilder will only generate the With*** methods. If you want the builder to also generate the Without*** methods, add the enum FluentBuilderMethods.WithAndWithout to the attribute.
using FluentBuilder;
[AutoGenerateBuilder(typeof(UserDto), FluentBuilderMethods.WithAndWithout)]
public partial class MyUserDtoBuilder
{
}