Use the Pagination object as a parameter in your controller methods to allow the client to call the function with limit and offset query parameters

[Route("[controller]")]
[ApiController]
class ObjectsController : ControllerBase
{
  ...

  [HttpGet]
  public ActionResult<PaginatedResponse<Object>> GetObjects(Pagination pagination)
  {
    return repository.GetObjects(pagination.limit, pagination.offset);
  }
}

The client can then call this method in the following way: GET http://{address}/objects?limit=10&offset=0.

The PaginatedResponse<T> contains a list of objects of type T, a total count of the number of items in the database and the given limit and offset. To construct a PaginatedResponse<T>, use the static factory method Create:

PaginatedResponse<T>.Create(IList<T> data, int limit, int offset, long total);

To transform a PaginatedResponse<T> into a PaginatedResponse<TF>, for example if the repository returns database objects and you want to transform these to API response data transfer objects the CreateFrom method is available:

PaginatedResponse<string> stringPR = ...
PaginatedResponse<int> intPR = PaginatedResponse.CreateFrom(stringPR, int.Parse);

An async method CreateFromAsync is also available.

To handle file uploads, you can use the DisableFormValueModelBindingAttribute and MultipartRequestHelper classes. These are based on Microsoft's own documentation on file uploads here.

Methods in a controller class decorated with the ApiController attribute will automatically validate incoming responses based on attributes you used in your models. Read the official docs here. This module adds some extra validation attributes:

Normally the validation will only check the top level attributes and not attributes in any nested objects. To validate nested objects, you can decorate properties with the ValidateObject attribute.

class Workflow
{
  ...
  [ValidateObject]
  public WorkflowStep Step { get; set; }
  ...
}

This attribute also works on lists.

Sometimes you want a property to be required only if another property has a certain value. This attribute allows you to specify this behavior. Use it as follows:

class WorkflowStep
{
  ...
  public bool PauseWorkflowAfterFinishing { get; set; }
  [RequiredIfOtherPropertyHasValue(nameof(PauseWorkflowAfterFinishing), true)]
  public long? PauseDurationInSeconds { get; set; }
  ...
}