Dapper.CustomTypeHandlers

Dapper.CustomTypeHandlers

Dapper custom type handlers to serialize/deserialize objects to Xml and Json. Can be also used to map GUID to a string.

Installation

Use NuGet Package Manager

Install-Package Dapper.CustomTypeHandlers

or .NET CLI

dotnet add package Dapper.CustomTypeHandlers

or just copy into the project file to reference the package

<PackageReference Include="Dapper.CustomTypeHandlers" Version="2.3.0" />

How to use

• Create class that implements IXmlObjectType or IJsonObjectType interface

public class Book
{
	public long Id { get; set; }
	public string Title { get; set; }
	public BookDescription Description { get; set; }
}

public class BookDescription : IXmlObjectType
{
	public Learn Learn { get; set; }
	public string About { get; set; }
	public Features Features { get; set; }
}

public class Learn
{
	public List<string> Points { get; set; }
}

public class Features
{
	public List<string> Points { get; set; }
}

• Register these new classes in Startup.cs

services.RegisterDapperCustomTypeHandlers(typeof(Book).Assembly);

• Create table in a database that contains a column of the XML type (SQL Server)

CREATE TABLE [dbo].[Books](
	[Id] bigint IDENTITY(1,1) NOT NULL,
	[Title] nvarchar(200) NOT NULL,
	[Description] xml NULL
	CONSTRAINT [PK_Books] PRIMARY KEY CLUSTERED
	(
		[Id] ASC
	)
)

To persist object as a JSON, you can use the nvarchar field (class should implement IJsonObjectType)

CREATE TABLE [dbo].[Books](
	[Id] bigint IDENTITY(1,1) NOT NULL,
	[Title] nvarchar(200) NOT NULL,
	[Description] nvarchar(max) NULL
	CONSTRAINT [PK_Books] PRIMARY KEY CLUSTERED
	(
		[Id] ASC
	)
)

• Use Dapper to save object data in the database

public async Task SaveBook(Book book)
{
	using (var conn = _connectionFactory.Connection())
	{
		await conn.ExecuteAsync(_@"INSERT INTO Books (Title, Description) VALUES (@Title, @Description)", book);
	}
}

How to Test

Every commit or pull request is built and tested on the Continuous Integration system.

To test locally:

• Download and install .NET 8.0 SDK
• Clone or download source code

git clone https://github.com/kubagdynia/Dapper.CustomTypeHandlers.git

• Start tests from the command line

dotnet test ./Dapper.CustomTypeHandlers/

Code Examples

• DapperMappers - An example of using Dapper with the custom Xml and Json mappers https://github.com/kubagdynia/DapperMappers

Technologies

List of technologies, frameworks and libraries used for implementation:

• .NET 8.0 (platform)
• Dapper (micro ORM)
• System.Text.Json (JSON serialization/deserialization)
• NUnit (testing framework)
• SQLite (database for testing purpose)
• FluentAssertions (fluent API for asserting the result of unit tests)

License

This project is licensed under the MIT License.