NotFoundResponse

Namespace: RA.Utilities.Api.Results

The NotFoundResponse class is a specialized model for creating standardized 404 Not Found responses. It is used when a requested resource cannot be found at the specified URI. It inherits from Response<T>, with the Result property typed as a NotFoundResult object.

🎯 Purpose

The NotFoundResponse class is a specialized model used to create standardized 404 Not Found API responses. It inherits from the base Response<T> class and is designed to clearly communicate when a requested resource does not exist.

Here's a breakdown of its key functions:

1. Simplifies 404 Responses: It reduces boilerplate code by automatically setting the response properties for a "not found" scenario:

• ResponseCode: Set to 404 (from BaseResponseCode.NotFound).
• ResponseType: Set to * **ResponseType.NotFound * **.
• ResponseMessage: Generates a clear, dynamic message like "Product with value '123' not found.".

2. Provides Structured Context: Unlike a simple text response, NotFoundResponse uses a NotFoundResult object as its payload. This object contains two key pieces of information:

• EntityName: The type of resource that was being looked for (e.g., "Product", "User").
• EntityValue: The identifier that was used in the search (e.g., 123, "john.doe@example.com").

3. Improves Client-Side Handling: This structured response allows clients to provide more intelligent feedback to the user. For example, a frontend application could parse this response and display a message like, "We couldn't find a product with the ID '123'."

Using NotFoundResponse ensures that all "not found" errors across your API are consistent, structured, and informative.

NotFoundResult

Represent an entity not found searched by given value.

Property	Type	Description
EntityName	string	The type of resource that was being looked for (e.g., "Product", "User").
EntityValue	object	The identifier that was used in the search (e.g., 123, "john.doe@example.com").

⚙️ How It Works

When you create an instance of NotFoundResponse, it pre-configures the following properties:

• ResponseCode: Set to 404 (from BaseResponseCode.NotFound).
• ResponseType: Set to ResponseType.NotFound.
• ResponseMessage: A dynamically generated message, such as "Product with value '123' not found.".
• Result: A NotFoundResult object containing the EntityName and EntityValue that were searched for.

🚀 Usage in a Controller

You can use this class in your controller actions when a database query or service call returns no result for a given identifier.

using Microsoft.AspNetCore.Mvc;
using RA.Utilities.Api.Results;

[ApiController]
[Route("api/[controller]")]
public class ProductsController : ControllerBase
{
    [HttpGet("{id}")]
    public IActionResult GetProduct(int id)
    {
        // Assume product is fetched from a service
        var product = _productService.GetById(id);

        if (product == null)
        {
            // Return a 404 Not Found with structured details
            return NotFound(new NotFoundResponse("Product", id));
        }

        return Ok(new SuccessResponse<Product>(product));
    }
}

Example JSON Output

A request to /api/products/999 (where product 999 does not exist) would produce the following JSON response body:

{
  "responseCode": 404,
  "responseType": "NotFound",
  "responseMessage": "Product with value '999' not found.",
  "result": {
    "entityName": "Product",
    "entityValue": 999
  }
}