Should a RESFTful Web API return the modified entity on an Update operation (Put)? - rest

Question

I'm creating a new Web API and I'm having a doubt regarding the Update operation (it's a basic CRUD). Should I return a DTO with the updated entity data? I want my API to be RESTful.

Answer 1

have a read here
https://www.rfc-editor.org/rfc/rfc7231
it says and I quote:
For a state-changing request like PUT (Section 4.3.4) or POST
(Section 4.3.3), it implies that the server's response contains the
new representation of that resource, thereby distinguishing it from
representations that might only report about the action (e.g., "It
worked!"). This allows authoring applications to update their
local copies without the need for a subsequent GET request.
However, you do not need to be too fixed on this, return a 201 for example when you create something is perfectly OK as well and you probably want to add the the unique identifier of the created resource.
For updates, a 200 would be ok as well. 204 can be acceptable as well as already mentioned.
The bottom line is ... return only the data you need, if you need to see the whole updated object then return it. If you don't then don't do it. Keep in mind that some objects can be quite big and have a whole object graph below them, there's no point sending too much data down the wire.
I guess the most important thing is to choose one way of doing things and then be consistent and use the same thing everywhere

Answer 2

First of all, returning a DTO has nothing to do with RESTful.
It's true that DTO is a pattern created with the purpose of transferring data to remote interfaces (and web services can be a good fit for this pattern).
However using DTOs won't make your application more or less RESTful. Your application can use DTOs to have more control over the data exposed in the REST API. Just that.
If your update operation relies on the PUT HTTP method (which is designed to replace the state of a resource with a new representation), you may want to return 200 or 204 status code to indicate that the operation has succeeded.
If you go for 200, you can return a representation of the new state of the recently updated resource. If you go for 204, no representation must be returned.
By representation I mean a JSON document, a XML document or any other content that can be used to represent the state of a given resource.

Answer 3

We normally return NoContentResult after update is successful. For example,
[HttpPut("{id}", Name = "UpdateUser")]
public IActionResult UpdateUser(Guid id, [FromBody] UserUpdateDto user)
{
if (user == null)
{
return BadRequest();
}
if (!_repository.UserExists(id))
{
return NotFound();
}
var entity = _repository.GetUser(id);
Mapper.Map(user, entity);
_repository.UpdateUser(entity);
return NoContent();
}
NoContent basically returns status code 204. The following is the source code of NoContentResult.
public class NoContentResult : StatusCodeResult
{
public NoContentResult()
: base(204)
{
}
}

Answer 4

Returning data from a PUT operation is optional, though not necessary. If theres anything you wanted to calculate in the model which will be useful for the client then return them, but otherwise a 204.