Wissance.WebApiToolkit

This lib helps to build REST API with C# and AspNet easily than writing it from scratch over and over in different projects.

1. Key Features

• REST API Controller with full CRUD contains only 20 lines of code (~ 10 are imports)
  • GET methods have built-in paging support;
  • GET methods have built-in sorting and filter by query parameters;
• support BULK operations with objects (Bulk Create, Update and Delete) on a Controller && interface level
• support to work with any persistent storage (IModelManager interface); Good built-in EntityFramework support (see EfModelManager class). See WeatherControl App which has 2 WEB API projects:
  • Wissance.WeatherControl.WebApi uses EntityFramework;
  • Wissance.WeatherControl.WebApi.V2 uses EdgeDb.

Key concepts:

1. Controller is a class that handles HTTP-requests to REST Resource.
2. REST Resource is equal to Entity class / Database Table
3. Every operation on REST Resource produce JSON with DTO as output. We ASSUME to use only one DTO class with all REST methods.

2. API Contract

• DTO classes:
  • OperationResultDto represents result of operation that changes Data in db;
  • PagedDataDto represents portion (page) of same objects (any type);
• Controllers classes - abstract classes
  • basic read controller (BasicReadController) contains 2 methods:
    • GET /api/[controller]/?[page={page}&size={size}&sort={sort}&order={order}] to get PagedDataDto<T> now we also have possibility to send ANY number of query params, you just have to pass filter func to EfModelManager or do it in your own way like in WeatherControl example with edgedb. We also pass sort (column name) && order (asc or desc) to manager classes, EfModelManager allows to sort by any column. Unfortunately here we have a ***ONE disadvantage*** - **we should override `Swagger` info to show query parameters usage!!!**

      Starting from 1.6.0 it is possible to see all parameters in Swagger and use them.

    • GET /api/[controller]/{id} to get one object by id
  • full CRUD controller (BasicCrudController) = basic read controller (BasicReadController) + Create, Update and Delete operations :
    • POST /api/[controller] - for new object creation
    • PUT /api/[controller]/{id} - for edit object by id
    • DELETE /api/[controller]/{id} - for delete object by id
  • full CRUD with Bulk operations (operations over multiple objects at once), Base class - BasicBulkCrudController = basic read controller (BasicReadController) + BulkCreate, BulkUpdate and BulkDelete operations:
    • POST /api/bulk/[controller] - for new objects creation
    • PUT /api/bulk/[controller] - for edit objects passing in a request body
    • DELETE /api/bulk/[controller]/{idList} - for delete multiple objects by id.

  Controllers classes expects that all operation will be performed using Manager classes (each controller must have it own manager)

• Managers classes - classes that implements business logic of application
  • IModelManager - interface that describes basic operations
  • EfModelManager- is abstract class that contains implementation of Get and Delete operations
  • EfSoftRemovableModelManager is abstract class that contains implementation of Get and Delete operations with soft removable models (IsDeleted = true means model was removed)

Example of how faster Bulk vs Non-Bulk:

Elapsed time in Non-Bulk REST API with EF is 0.9759984016418457 secs.
Elapsed time in Bulk API with EF is 0.004002094268798828 secs.

as a result we got almost ~250 x faster API.

3. Requirements

There is only ONE requirement: all Entity classes for any Persistence storage that are using with controllers & managers MUST implements IModelIdentifiable<T> from Wissance.WebApiToolkit.Data.Entity. If this toolkit should be used with EntityFramework you should derive you resource manager from EfModelManager it have built-in methods for:

• get many items
• get one item by id
• delete item by id

4. Toolkit usage algorithm with EntityFramework

Full example is mentioned in section 6 (see below). But if you are starting to build new REST Resource API you should do following:

1. Create a model (entity) class implementing IModelIdentifiable<T> and DTO class for it representation (for soft remove also add IModelSoftRemovable implementation), i.e.: ```csharp public class BookEntity : IModelIdentifiable { public int Id {get; set;} public string Title {get; set;} public string Authors {get; set;} // for simplicity public DateTimeOffset Created {get; set;} public DateTimeOffset Updated {get; set;} }

public class BookDto { public int Id {get; set;} public string Title {get; set;} public string Authors {get; set;} }

2. Create a factory function (i.e. static function of a static class) that converts `Model` to `DTO` i.e.:
```csharp
public static class BookFactory
{
    public static BookDto Create(BookEntity entity)
    {
        return new BookDto
        {
            Id = entity.Id,
            Title = entity.Title,
            Authors = entity.Authors;
        };
    }
}

1. Create IModelContext interface that has you BookEntity as a DbSet and it’s implementation class that also derives from DbContext (Ef abstract class): ```csharp public interface IModelContext { DbSet Books {get;set;} }

public MoidelContext: DbContext, IModelContext { // todo: not mrntioned here constructor, entity mapping and so on public DbSet Books {get; set;} }

4. Configure to inject `ModelContext` as a `DbContext` via `DI` see [Startup](https://github.com/Wissance/WeatherControl/blob/master/WeatherControl/Wissance.WeatherControl/Startup.cs) class
5. Create `Controller` class and a manager class pair, i.e. consider here full `CRUD`
```csharp
[ApiController]
public class BookController : BasicCrudController<BookDto, BookEntity, int, EmptyAdditionalFilters>
{
    public BookController(BookManager manager)
    {
        Manager = manager;  // this is for basic operations
        _manager = manager; // this for extended operations
    }
    
    private BookManager _manager;
}

public class BookManager : EfModelManager<BookEntity, BookDto, int, EmptyAdditionalFilters>
{
    public BookManager(ModelContext modelContext, ILoggerFactory loggerFactory) : base(modelContext, BookFactory.Create, loggerFactory)
    {
        _modelContext = modelContext;
    }
    
    public override async Task<OperationResultDto<StationDto>> CreateAsync(StationDto data)
    {
        // todo: implement
    }
    
    public override async Task<OperationResultDto<StationDto>> UpdateAsync(int id, StationDto data)
    {
        // todo: implement
    }
    
    private readonly ModelContext _modelContext;
}

Last generic parameter in above example - EmptyAdditionalFilters is a class that holds additional parameters for search to see in Swagger, just specify a new class implementing IReadFilterable i.e.:

public class BooksFilterable : IReadFilterable
{
    public IDictionary<string, string> SelectFilters()
    {
            IDictionary<string, string> additionalFilters = new Dictionary<string, string>();
            if (!string.IsNullOrEmpty(Title))
            {
                additionalFilters.Add(FilterParamsNames.TitleParameter, Title);
            }

            if (Authors != null && Authors.Length > 0)
            {
                additionalFilters.Add(FilterParamsNames.AuthorsParameter, string.Join(",", Authors));
            }

            return additionalFilters;
    }
        
    [FromQuery(Name = "title")] public string Title { get; set; }
    [FromQuery(Name = "author")] public string[] Authors { get; set; }
}

5. Nuget package

You could find nuget-package here

6. Examples

Here we consider only Full CRUD controllers because Full CRUD = Read Only + Additional Operations (CREATE, UPDATE, DELETE), a full example = full application created with Wissance.WebApiToolkit could be found here: https://github.com/Wissance/WeatherControl

[ApiController]
public class StationController : BasicCrudController<StationDto, StationEntity, int, EmptyAdditionalFilters>
{
    public StationController(StationManager manager)
    {
        Manager = manager;  // this is for basic operations
        _manager = manager; // this for extended operations
    }
    
    private StationManager _manager;
}

public class StationManager : EfModelManager<StationEntity, StationDto, int>
{
    public StationManager(ModelContext modelContext, ILoggerFactory loggerFactory) : base(modelContext, StationFactory.Create, loggerFactory)
    {
        _modelContext = modelContext;
    }

    public override async Task<OperationResultDto<StationDto>> CreateAsync(StationDto data)
    {
        try
        {
            StationEntity entity = StationFactory.Create(data);
            await _modelContext.Stations.AddAsync(entity);
            int result = await _modelContext.SaveChangesAsync();
            if (result >= 0)
            {
                return new OperationResultDto<StationDto>(true, (int)HttpStatusCode.Created, null, StationFactory.Create(entity));
            }
            return new OperationResultDto<StationDto>(false, (int)HttpStatusCode.InternalServerError, "An unknown error occurred during station creation", null);

            }
        catch (Exception e)
        {
            return new OperationResultDto<StationDto>(false, (int)HttpStatusCode.InternalServerError, $"An error occurred during station creation: {e.Message}", null);
        }
    }

    public override async Task<OperationResultDto<StationDto>> UpdateAsync(int id, StationDto data)
    {
        try
        {
            StationEntity entity = StationFactory.Create(data);
            StationEntity existingEntity = await _modelContext.Stations.FirstOrDefaultAsync(s => s.Id == id);
            if (existingEntity == null)
            {
                return new OperationResultDto<StationDto>(false, (int)HttpStatusCode.NotFound, $"Station with id: {id} does not exists", null);
            }

            // Copy only name, description and positions, create measurements if necessary from MeasurementsManager
            existingEntity.Name = entity.Name;
            existingEntity.Description = existingEntity.Description;
            existingEntity.Latitude = existingEntity.Latitude;
            existingEntity.Longitude = existingEntity.Longitude;
            int result = await _modelContext.SaveChangesAsync();
            if (result >= 0)
            {
                return new OperationResultDto<StationDto>(true, (int)HttpStatusCode.OK, null, StationFactory.Create(entity));
            }
            return new OperationResultDto<StationDto>(false, (int)HttpStatusCode.InternalServerError, "An unknown error occurred during station update", null);

        }
        catch (Exception e)
        {
             return new OperationResultDto<StationDto>(false, (int)HttpStatusCode.InternalServerError, $"An error occurred during station update: {e.Message}", null);
        }
            
    }

    private readonly ModelContext _modelContext;
}

JUST 2 VERY SIMPLE CLASSES ^^ USING WebApiToolkit

7. Extending API

7.1 Add new methods to existing controller

Consider we would like to add method search to our controller:

[HttpGet]
[Route("api/[controller]/search")]
public async Task<PagedDataDto<BookDto>>> SearchAsync([FromQuery]string query, [FromQuery]int page, [FromQuery]int size)
{ 
    OperationResultDto<Tuple<IList<BookDto>, long>> result = await Manager.GetAsync(page, size, query);
    if (result == null)
    {
        HttpContext.Response.StatusCode = (int)HttpStatusCode.InternalServerError;
    }

    HttpContext.Response.StatusCode = result.Status;
    return new PagedDataDto<TRes>(pageNumber, result.Data.Item2, GetTotalPages(result.Data.Item2, pageSize), result.Data.Item1);
}

7.2 Add security to protect you API

We have additional project to protect API with Keycloak OpenId-Connect. pass IHttpContextAccessor to Manager class and check something like this: ClaimsPrincipal principal = _httpContext.HttpContext.User;

8. Additional materials

You could see our articles about Toolkit usage:

• Medium article about v1.0.x usage
• Dev.to article about v1.0.x usage

9. Contributors