REST API Design: Path variable vs request body on UPDATE (Best practices)-CodePudding

When creating an UPDATE endpoint to change a resource, the ID should be set in the path variable and also in the request body. Before updating a resource, I check if the resource exists, and if not, I would respond with 404 Not Found.

Now I ask myself which of the two information I should use and if I should check if both values are the same.

For example:

PUT /users/42

// request body
{
 "id": 42,
 "username": "user42"
}

CodePudding user response：

You should PUT only the properties you can change into the request body and omit read-only properties. So you should check the id in the URI, because it is the only one that should exist in the message.

CodePudding user response：

It is convenient to accept the "id" field in the payload. But you have to be sure it is the same as the path parameter. I solve this problem by setting the id field to the value of the path parameter (be sure to explain that in the Swagger of the API). In pseudo-code :

idParam = request.getPathParam("id");
object = request.getPayload();
object.id = idParam;

So all these calls are equivalent :

PUT /users/42   {"id":"42", ...}
PUT /users/42   {"id":"41", ...}
PUT /users/42   {"id":null, ...}
PUT /users/42   {...}

CodePudding user response：

Why do you need the id both in URL and in the body? because now you have to validate that they are both the same or ignore one in any case. If it is a requirement for some reason, than pick which one is the one that is definitive and ignore the other one. If you don't have to have this strange duplication, than I'd say pass it in the body only