What's the "correct" HTTP status code for valid request that fail for a valid business reason? [closed] - rest

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Wanted to get your opinion on this, probably there's isn't an absolute right answer, but I want to see what you think is the more correct approach.
If there's nothing structurally wrong with a request (it's in the correct format) and all the fields are valid (field values not too long, required fields have a value etc...) but the call failed because of a business reason, for example "you cannot change a status of task that isn't assigned to you", what should be the response in this case:
200 with a JSON which explains the error:
{
error: {
code :120,
message: "you cannot change a status of a task that isn't assigned to you"
}
}
or maybe a 4xx response with a similar body:
{
error: {
code :120,
message: "you cannot change a status of a task that isn't assigned to you"
}
}

While I want to agree with #EJK, the spec he linked is out of date.
The most current one is RFC7231: https://www.rfc-editor.org/rfc/rfc7231#section-6.5.1 which changed the meaning of the old 403 FORBIDDEN response status.
Answer:
So for the sake of this question 400 BadRequest should be used, because whoever consumed your service, case being the client, is wrong and can possible fix his request
The 400 (Bad Request) status code indicates that the server cannot or
will not process the request due to something that is perceived to be
a client error (e.g., malformed request syntax, invalid request
message framing, or deceptive request routing).
An example from your own use case:
The client now knows that the error "you cannot change a status of a task that isn't assigned to you" is his own fault. And he may even try to issue a different new (valid) request.

403 Forbidden seems like a good match.
From http://www.w3.org/Protocols/rfc2616/rfc2616-sec10.html#sec10.4.4.
The server understood the request, but is refusing to fulfill it.
Authorization will not help and the request SHOULD NOT be repeated. If
the request method was not HEAD and the server wishes to make public
why the request has not been fulfilled, it SHOULD describe the reason
for the refusal in the entity. If the server does not wish to make
this information available to the client, the status code 404 (Not
Found) can be used instead.
Thus, option 2, as you have proposed, seems good as it also describes the reason for the failure.

Related

HTTP Error Code while trying to change an immutable object?

I have a quiz in which I can give an answer to a question over a restful API. The request will transmit the answer to the question over a PUT-Request to an URL like “/question/{id}/answer”. But each question can only be answered once. The answer can be queried over a get request but can never be changed again. What HTTP Error Code do I return when the client tries to change the immutable answer with a PUT request?
I tried this error codes:
405 Method Not Allowed: But in the first place a PUT is fine. But once the object is set a PUT is not allowed anymore. Is it OK if the list of allowed methods change over time?
409 Conflict: Would work, but the RfC says “his code is only allowed in situations where it is expected that the user might be able to resolve the conflict and resubmit the request.” And here the client would not be able to resolve the conflict.
400 Bad Request: It is in general a bad request but not “due to malformed syntax.”
So, is it a Server Error (5xx)? In case of a 500 Internal Server Error the RfC states that “The server encountered an unexpected condition”. But we expect the object to become immutable at some point.
Is it OK if the list of allowed methods change over time?
Yes.
Allow header field in a 405 response containing a list of the target resource's currently supported methods. -- RFC 7231
Note: currently supported methods....

Swift: check for successful HTTP status code [closed]

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I'd like to see if an HTTPURLResponse statusCode begins with 2 to indicate success. Does it make more sense to see if it falls between 200 and 299, inclusive? Or does Swift have a builtin function to see if an HTTP status code represents success?
That is, given,
var statusCode: Int = ..
which, if any, of the following expressions would be preferred?
let success = String(statusCode).prefix(1) == "2"
let success = statusCode < 300 && statusCode >= 200
The relevant documentation reads,
The first digit of the Status-Code defines the class of response. The
last two digits do not have any categorization role. There are 5
values for the first digit:
- 1xx: Informational - Request received, continuing process
- 2xx: Success - The action was successfully received,
understood, and accepted
- 3xx: Redirection - Further action must be taken in order to
complete the request
- 4xx: Client Error - The request contains bad syntax or cannot
be fulfilled
- 5xx: Server Error - The server failed to fulfill an apparently
valid request
https://www.ietf.org/rfc/rfc2616.txt
You are right that anything between 200 and 299 (inclusive) means success.
However, it's not a complete picture. A 3XX response might mean that you don't know if the request is successful yet, and you need to follow the redirect to find out what the real status was.
A 303 redirect can lead to a URI that returns a 404, or a 200 OK.

Which HTTP code should be return from REST API?

im currently working on a website which has Spring at backend and Angularjs at front side and we had discussed about back end responses to handle frontend's message dialogs and i have a question to ask:
Lets say i have an API :
GET : /getstatistics
Request params : fromTime,toTime ( in timestamp format)
And if client make a request with invalid params like a string, which response code should be returned from server ? HTTP 400 bad request and response body with a message " fromTime and toTime should be in timestamp format" or HTTP 200 with same message?
I saw some Google's APIs for example Oauth, they're returning code 200 for a request with invalid access_token but ,in our project my opinion it should be HTTP 400 because Javascript has success and error callbacks, is it better for it just pop a red color dialog with message inside rather than a HTTP 200 code then still need to check the content of the message?
Any advides and opinions are appreciated.
Thanks!
You should be returning a 400 error for bad request. Check out this reference.
The server cannot or will not process the request due to something
that is perceived to be a client error (e.g., malformed request
syntax, invalid request message framing, or deceptive request
routing).
Please have a look at RFC7231#section-6
A client MUST understand the class of any status code, as indicated by
the first digit
and,
4xx (Client Error): The request contains bad syntax or cannot be
fulfilled
Bad syntax can be something like you've mentioned in your question (making a request with invalid parameters, like a string).
I keep these two references handy whenever I'm designing RESTful APIs, might be helpful for you too:
https://httpstatuses.com/
http://www.restapitutorial.com/httpstatuscodes.html
Yes you are right, the http code should be 400 in your case. Your discussion here normally should be whether you need to return 400 or 422. For this you can check the accepted response for this SO question 400 vs 422 response to POST of data
I think it has something to do with how the parameters are used. If you use the resource, then a 404 should return. If the data is simply not valid then we decide to set a 409 Status to the request. It can't full fill it at 100% because of missing/invalid parameter.
HTTP Status Code "409 Conflict" was for us a good try because it's
definition require to include enough information for the user to
recognize the source of the conflict.
Reference: w3.org/Protocols/
Edit:
In any case, the status code 200 is incorrect here because there is an error. In response, you can then return specific information like this:
{
"errors": [
{
"userMessage": "Sorry, the parameter xxx is not valid",
"internalMessage": "Invalid Time",
"code": 34,
"more info": "http://localhost/"
}
]
}

REST API & HTTP Status Code

I have a bunch of PUT operations which execute actions on the input resource.
Let's make an example: I have a payment operation in my API which state that a credit card must be charged by a specific Amount.
In my code I first verify if there is sufficient credit on the card and then execute the operation. If there is'nt sufficient amount I simply return 400 but I am not sure it is correct.
Which is the correct HTTP Status Code in cases like this?
I can, of course send a response with HTTP 200 and attach a payload with further details explaining the error. I can also send back an HTTP 400 Bad Request or even better an HTTP 412 Precondition Failed.
Which is the correct code to send in the response in scenario like this where the validation failed? Is there any resource that I can read to understand the rationale behind HTTP Status Codes and HTTP Verbs?
Use 422 Unprocessable Entity.
The 422 status code means the server understands the content type of the request entity (hence a 415 Unsupported Media Type status code is inappropriate), and the syntax of the request entity is correct (thus a 400 Bad Request status code is inappropriate) but was unable to process the contained instructions.
Failing that, simply use 400 for any error having to do with your business domain. As of June 2004, the description for error 400 was amended to read:
The server cannot or will not process the request due to something that is perceived to be a client error
If the operation failed because of data sent by the user (it seems to be the case), you should use status codes 400 (general) or 422 (more precise but coming from the WebDAV spec). You can return back additional hints about the error within the payload (the structure is up to you) like:
{
error: {
"field": "amount",
"message": "The amount isn't correct - Sufficient credit."
}
}
I think that code 412 doesn't apply here since it must be returned when your server doesn't meet a condition specified by the client (see headers If-* like If-Match, If-Modified-Since, ...).
Hope it helps you,
Thierry
IMO: I would stick with 200 and then parse out the response and deal with that. HTTP status codes are protocol status code, not something that you should use for dealing with application logic.
{
"error": {
"field": "amount",
"message": "The amount isn't correct - Sufficient credit."
}
}
In case of the above code, the service call worked fine warranting a return code 200. However, you application logic now needs to deal with the error reported.
If we are using a HTTP status code to indicate error, we will start to get flagged in our logs etc. even though there was no technical error.

HTTP status code in REST API for using GET to query a “Not Ready Yet, Try Again Later” resource?

First of all, I've read some relevant posts:
Best HTTP status code in REST API for “Not Ready Yet, Try Again Later”? It is about GET an item
Is it wrong to return 202 “Accepted” in response to HTTP GET? It is about GET an item
HTTP Status Code for Resource not yet available It is about POST
HTTP status code for in progress? It is about GET but no clear answer.
but I still think I should raise my question and my thoughts here. What should be the HTTP status code in REST API for using GET to QUERY a “Not Ready Yet, Try Again Later” resource? For example, client tries to query all local news happen in future(!) by make an HTTP GET to this url: http://example.com/news?city=chicago&date=2099-12-31 so what shall the server reply?
These are the http status code I considered, their rfc definition and why I am not fully satisfied with:
3xx Redirection. Comment: Not an option because there is no other link to be redirected to.
503 Service Unavailable: The server is currently unable to handle the request due to a temporary overloading or maintenance of the server. The implication is that this is a temporary condition which will be alleviated after some delay. If known, the length of the delay MAY be indicated in a Retry-After header. Comment: The retry behavior is desired, but semantically the situation is not server's fault at all, so all 5xx look weird.
4xx Client Error. Comment: Looks promising. See below.
413 Request Entity Too Large: The server is refusing to process a request because the request entity is larger than the server is willing or able to process. ... If the condition is temporary, the server SHOULD include a Retry- After header field to indicate that it is temporary and after what time the client MAY try again. Comment: The retry behavior is desired, however the "Entity Too Large" part is somewhat misleading.
417 Expectation Failed: The expectation given in an Expect request-header field (see section 14.20) could not be met by this server. Comment: So it should be caused by an Expect request-header, not applicable to my case.
406 Not Acceptable: The resource ... not acceptable according to the accept headers sent in the request. Comment: so it is caused by the Accept request-header, not applicable to my case.
409 Conflict: The request could not be completed due to a conflict with the current state of the resource. This code is only allowed in situations where it is expected that the user might be able to resolve the conflict and resubmit the request. ... Conflicts are most likely to occur in response to a PUT request. Comment: This one is close. Although my case is not about PUT, and isn't actually caused by conflict.
404 Not Found: The server has not found anything matching the Request-URI. Comment: Technically, my url path (http://example.com/news) DOES exist, it is the parameters causing problems. In this case, returning an empty collection instead of a 404, is probably more appropriate.
403 Forbidden: The server understood the request, but is refusing to fulfill it. Authorization will not help and the request SHOULD NOT be repeated. Comment: Generally this is supposed to be used in any restricted resource?
400 Bad Request: The request could not be understood by the server due to malformed syntax. The client SHOULD NOT repeat the request without modifications. Comment: It is not true in my case. My server understands the request, its syntax is good, only the meaning is bad.
2xx Successful. Comment: If 4xx doesn't work, how about 2xx? See below.
200 OK. Comment: Fine. So what should I include in the response body? null or [] or {} or {"date": "2099-12-31", "content_list": null} or ... which one is more intuitive? On the other hand, I prefer a way to clearly differentiate the minor "future news" error from the more common "all query criteria are good, just no news this day" situation.
202 Accepted: The request has been accepted for processing, but the processing has not been completed. The request might or might not eventually be acted upon. Comment: Providing that we can use 202 in a GET request, it is acceptable. Then refer to the 200 comment.
204 No Content: The server has fulfilled the request but does not need to return an entity-body. Comment: Providing that we can use 204 in a GET request, it is acceptable. Just don't know whether this is better than 202 or 200.
More on 2xx: Comment: I assume all 2xx response will likely be cached somewhere. But in my case, if I return an empty body for "tomorrow's news", I don't want it to be cached. Ok, explicitly specify the "no cache" headers should help.
Your thoughts?
Use 404.
Your objection to it is based on a popular understanding of a URI as not including the querystring. "Because I have multiple URI's that map to the same handler," goes the logic, "my resource does in fact exist and is just being parameterized by querystring args."
This is incorrect. As the URI spec itself says in Section 3.3 (emphasis mine),
"The path component contains data, usually organized in hierarchical
form, that, along with data in the non-hierarchical query
component (Section 3.4), serves to identify a resource within the
scope of the URI's scheme and naming authority (if any)."
Resources are identified by URI's, and any change to any part of an absolute-URI identifies a separate resource. Tweet that to everyone you know once a day until they tell you to stop. Therefore a 404 is a perfect match: "The 404 (Not Found) status code indicates that the origin server did not find a current representation for the target resource or is not willing to disclose that one exists."
You are retrieving the news for that day, which is a valid day, there just isn't any news. A 200 response of an empty body, or a what ever makes sense based on the mediatype would seem the logical. This depends on the media type you have decided with the client.
404 would make more sense if the date format was wrong (you asked for the 45th day of November, or asked for a city that doesn't exist.)
As an aside the URL would be better in the format http://example.com/news/chicago/2099-12-31 since that is the specific resource you want to retrieve. This format would make things like 404s clearer as well.