Population.NET

What is Population.NET?

Population.NET is a .NET library designed to optimize data retrieval from the server, maximizing performance when clients make API calls. It allows clients to specify the exact fields they need, reducing unnecessary data transfer by avoiding the retrieval of all fields by default.

Inspired by the populate feature in Strapi for Node.js, Population.NET brings similar capabilities to .NET, enhancing API flexibility and efficiency.

Additionally, the library includes essential data manipulation features such as filters, search, sort, and paging, all designed to handle complex data types like objects and collections.

With Population.NET, you can effortlessly build powerful and efficient APIs that meet the demands of modern applications.

Main Features

• Built-in BaseEntity Support: Provides a built-in abstract BaseEntity class to simplify entity creation
• QueryContext: Provides a common query params request class for search APIs.
• Simple Population: Easily retrieve and populate data with a simple and intuitive API, inspired by Strapi's populate feature.
• Population with Filters, Search, Sort, and Paging: Combine population capabilities seamlessly with filtering, searching, sorting, and pagination to handle complex data queries efficiently.

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⏳ Installation

Using Package Manager

To install Population.NET in using Using Package Manager, follow these steps:

1. Open Visual Studio 2022.
2. Go to Tools -> NuGet Package Manager -> Manage NuGet Packages for Solution....
3. Search for Population.NET in the Browse tab and install the package.

or

Add the following package reference to your project file:

<PackageReference Include="Population.NET" Version="1.8.1" />

Using .NET CLI

dotnet add package Population.NET --version 1.8.1

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🖐 Requirements

To use Population.NET, ensure the following requirements are met:

1. Using .NET 8 or higher:
   Make sure your project is targeting .NET 8 or a newer version. You can set the target framework in your .csproj file:

   <TargetFramework>net8.0</TargetFramework>
   

2. AutoMapper Configuration: Configure AutoMapper in your project to handle object mapping. Below is a simple example of how to set up AutoMapper:

   using AutoMapper;
   
   public class MappingProfile : Profile
   {
       public MappingProfile()
       {
           // Example mapping configuration
           CreateMap<Entity, Response>();
       }
   }

   Then, register the mapping configuration in your project (e.g., in Program.cs):

   var mapperConfig = new MapperConfiguration(cfg => 
   {
       cfg.AddProfile<MappingProfile>();
   });
   
   IMapper mapper = mapperConfig.CreateMapper();
   builder.Services.AddSingleton(mapper);

   or

   builder.Services.AddAutoMapper(typeof(ProfileAssemblyType))

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🎉 Example Project!

To help you get started with Population.NET, we have prepared an example project that demonstrates its key features and best practices.

📥 Download or clone the project now from GitHub:

🔗 Example-Population GitHub Repository

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🚀 Usage Example

💥 Built-in BaseEntity Support

Population.NET provides a built-in abstract BaseEntity class to simplify entity creation. It supports automatic ID generation and creation timestamps.

 public abstract class BaseEntity : BaseEntity<Guid>, IGuidIdentify
 {
     protected BaseEntity() => Id = NewId.Next().ToGuid();
 }

 public abstract class BaseEntity<TId> : IEntity<TId>
 {
     public TId Id { get; set; } = default!;
     public virtual DateTimeOffset CreatedAt { get; set; } = DateTimeOffset.UtcNow;
 }

Note

When building entity models using the integrated BaseEntity, if the CompileQueryAsync extension method is used without specifying sorting, the results will be sorted by CreatedAt: Desc by default.

💥 QueryContext Class

A common query params request class, using for APIs integrate with Population.NET

 public class QueryContext
 {
     public PagingDescriptor Pagination { get; set; } = new();

     public List<SortDescriptor>? Sort { get; set; }

     public List<FilterDescriptor>? Filters { get; set; }

     public SearchDescriptor? Search { get; set; }

     public PopulateDescriptor Populate { get; set; } = new();
 }

💥 Simple Population

• Fields Selection

• Without populate

• Populate all relations and fields, 1 level deep

• Populate specific relations and fields

  Normally

  We will create a simple GET API to fetch all users using AutoMapper's ProjectTo method.

      [HttpGet("UsingProjectTo")]
      public async Task<IActionResult> GetAllAsync()
      {
          List<UserResponse> response = await context.Users
              ProjectTo<UserResponse>(mapper.ConfigurationProvider)
              .ToListAsync();
  
          return Ok(response);
      }

  By default, when using ProjectTo from AutoMapper without additional filtering, the data returned will include all properties defined in the response DTOs class. This behavior can lead to overfetching of data, especially when the response class contains nested relationships or unnecessary fields.

  ⚡ Using population

  Create GET API to fetch all users using AutoMapper's ProjectDynamic method.

      [HttpGet("SimplePopulation")]
      public async Task<IActionResult> GetAllWithSimplePopulationAsync([FromQuery] QueryContext queryContext)
      {
          List<dynamic> response = await context.Users
              .ProjectDynamic<UserResponse>(mapper, queryContext.Populate)
              .ToListAsync();
  
          return Ok(response);
      }

  🔥 1. Fields Selection

  Queries can accept a fields parameter to select only specific fields. By default, only the following types of fields are returned:

  • String types: string, uuid, ...

  • Date types: DateTime, DateTimeOffset, ....

  • Number types: integer, long, float, and decimal.

  • Generic types: boolean, array of primitive types.

    Example Use Cases

    Use case	Example parameter syntax
    Select a single field	fields=name
    Select multiple fields	fields=name&fields=Email
    Select populate and fields	populate[Role][fields]=name

  [!NOTE] Field selection does not work on relational. To populate these fields, use the populate parameter.

  Example Request: Return only name, description, Role.Name fields

  GET /api/User/SimplePopulation?fields=name&fields=Email&populate[Role][fields]=name

  🔥 2. Without populate

  Without the populate parameter, a GET request will only return the default fields and will not include any related data.

  Example Request:

  GET /api/User/SimplePopulation

  Example Response:

  [
      {
          "name": "John Doe",
          "email": "[email protected]",
          "userName": "johndoe123",
          "password": "Password@123",
          "status": 1,
          "id": "74850000-9961-b42e-a80d-08dd1e75109d",
          "createdAt": "2024-12-17T08:30:29.463949+00:00"
      },
      ...
  ]

  🔥 3. Populate all relations and fields, 1 level deep

  You can return all fields and relations. For relations, this will only work 1 level deep, to prevent performance issues and long response times.

  To populate everything 1 level deep, add the populate=* parameter to your query.

  Example Request:

  GET /api/User/SimplePopulation?populate=*

  Example Response:

  [
      {
          "name": "John Doe",
          "email": "[email protected]",
          "userName": "johndoe123",
          ...
          "role": {
              "name": "Admin",
              "description": "Administrator role with full access",
              "id": "74850000-9961-b42e-baae-08dd1e75109d",
              "createdAt": "2024-12-17T08:30:29.525732+00:00"
          }
      },
      ...
  ]

  [!NOTE] If your data includes additional relationships beyond role, such as organization, or groups using the populate=* parameter will also include those relationships as long as they are at a depth of 1

  🔥 4. Populate specific relations and fields

  You can also populate specific relations and fields, by explicitly defining what to populate. This requires that you know the name of fields and relations to populate.

  [!NOTE] Relations and fields populated this way can be 1 or several levels deep

  Populate fields and relationships at 1 level deep

  Example parameter syntax
  populate=role
  populate[role]=true
  populate[role]=*
  populate[Role][fields]=name

  [!NOTE] The first three lines have different syntax but the same result.

  Populate fields and relationships at a depth greater than 1 level

  Example parameter syntax
  populate[role][populate]=permissions
  populate[role][populate][permissions]=true
  populate[role][populate][permissions]=*

💥 Population with Filters, Search, Sort, and Paging

• Example usage

• Pagination

• Searching

• Sorting

• Filtering

  To use Population with Filters, Search, Sort, and Paging, we will utilize the CompileQueryAsync extension method instead of ProjectDynamic.

  Example usage:

  [HttpGet("PopulationWithDataManipulation")]
  public async Task<IActionResult> GetAllWithSimplePopulationWithDataManipulationAsync([FromQuery] QueryContext queryContext)
  {
      PaginationResponse<dynamic> response = await context.Users.CompileQueryAsync<UserResponse>(queryContext, mapper);
  
      return Ok(response);
  }

  Pagination

  To paginate results by page, use the following parameters:

  Parameter	Type	Description	Default
  pagination[page]	Integer	Page number	1
  pagination[pageSize]	Integer	Page size	10

  Example Request:

  GET /api/User/PopulationWithDataManipulation?pagination[page]=1&pagination[pageSize]=15

  Searching

  To search for data, use the following parameters:

  Parameter	Type	Description	Default
  search[keyword]	String	Search keyword	null
  search[fields]	Array(String)	A collection fields search	null

  Example Request:

  GET /api/User/PopulationWithDataManipulation?search[keyword]=Jane&search[fields]=userName&search[fields]=email

  [!NOTE] If a search keyword is used but no specific search fields are provided, the search will apply to all selected fields except for fields of the following types:

  • Enum
  • Guid
  • Boolean
  • TimeOnly
  • Fields marked with the NotSearchAttribute.

  Sorting

  To sort data by one or multiple fields, pass sort parameters using array syntax:

  Example Request:

  GET /api/User/PopulationWithDataManipulation?sort[0]=createdAt:asc&sort[1]=name:desc

  [!NOTE] :asc is default order, can be omitted

  Filtering

  Queries can accept a filters parameter with the following syntax:

  GET /api/:pluralApiId?filters[field][operator]=value

  The following operators are available:

  Operator	Description
  $eq	Equal
  $ne	Not equal
  $lt	Less than
  $lte	Less than or equal to
  $gt	Greater than
  $gte	Greater than or equal to
  $in	Included in an array
  $notIn	Not included in an array
  $contains	Contains
  $notContains	Does not contain
  $null	Is null
  $notNull	Is not null
  $startsWith	Starts with
  $notstartsWith	Not start with
  $endsWith	Ends with
  $notendsWith	Not Ends with

  Example Request:

  GET /api/User/PopulationWithDataManipulation?filters[username][$eq]=janesmith456

  $in orperator

  GET /api/User/PopulationWithDataManipulation?filters[status][$in][0]=1&filters[status][$in][1]=2

  
  

  [!NOTE] null operator is not available at the moment

Contributing

Contributions are welcome! Feel free to submit a pull request or open an issue to discuss any changes or improvements.

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License

This project is licensed under the MIT License. See the LICENSE file for more details.

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Authors

• Authentic

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Acknowledgements

Population.NET seamlessly integrates with:

• AutoMapper
• Entity Framework Core

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