I've implemented logging of all requests/responses using (in my AppHost.cs):
this.RequestFilters.Add(serviceLogFilter.LogRequest);
this.ResponseFilters.Add(serviceLogFilter.LogResponse);
During the logging of the request, I get the new ID from the logging table and put it into IHttpRequest.Items.
My question is: when an error occurs, like if the validation of the incoming data fails, or my business logic throws an Exception, is there a way I can customize the returned error to contain my log reference? Preferably by adding a JSON body to the error response. Alternatively, setting a custom HTTP header?
The idea is that my customer could give me a log reference if something unexcpected happens, and I would find his request and could easily reproduce the problem.
See this question on different ways to Handle exceptions from the old and New API.
To use the IHttpRequest.Items dictionary to pass data between request filters, services and response filters in the same request.
Also the InMemoryRollingRequestLogger implementation for the Request Logger plugin shows another way to be able to log all requests.
Related
I have this json feed.
I am unable to load this into Appgyver
I have set the following required settings:
- parameter app_name with the correct value
- added the reuired header X-DREAMFACTORY-APPLICATION-NAME
I always get the Oops, Unable to load resource's data model. error
Anyone who has a clue?
I am not very familiar with AppGyver, but I know it's been used with DreamFactory successfully by others. You have not provided enough information, but I will attempt to give you troubleshooting steps from the DreamFactory side.
First, are you definitely authenticating and passing a valid X-DreamFactory-Session-Token header? I can tell that you don't have guest access enabled (to make calls without authentication) because when I navigate to your link I receive a 401 with "There is no valid session for the current request."
Second, what is the call you're making from AppGyver? Is it a GET to simply list resources of a DB called vlaamse_vinyl, or what?
Finally, if you are passing X-DreamFactory-Application-Name in addition to the URI parameter ?app_name=vlaamse_vinyl this is redundant. Perhaps that is preventing your call from succeeding.
I have a webservice method that if I call directly via url GET returns XML without issue.
However, POST to that same url with Content-Type Json, it fails.
I think I can figure out the issue (I'm guessing it's an encoding or bad character somewhere in there) but I don't know how to debug the problem.
If I set a breakpoint in the webservice, it runs to completion. The failure appears to be happening AFTER the method returns, but BEFORE the json is returned to the caller.
How can I get in between to trace the error?
Please let me know if I can provide more context to help, but I really just need to know how to get in there.
EDIT:
The web service is configured to receive POST and return JSON and in fact DOES correctly return JSON in some cases. However, there are certain calls that are failing, so I need a way to trace this or debug it somehow and figure out why some calls are not working.
The web service is likely not configured to receive POST requests, especially if you are receiving a 405 Method Not Allowed response status.
Although I didn't find a way to debug or intercept the request to find the exact answer, it turns out the problem was the size of the content being returned by the webservice. Following this answer: ASP.NET WebMethod with jQuery json, is there a size limit?
and increasing the json limit fixed the issue!
Is there a way I could have trapped this to find the error without just guessing it was a size limit?
So we have a Web Api that for some 3rd party automation, the 3rd party will make a call to our API try Update some items.
Our Web Api will check if the items exists and some dependencies items (complex object in xaml/json) that need also be update before do the actual update process.
So the problem here is, if we found some dependencies that client haven't provided, I want to be able to response a Error Response message to the client with the exception and dependencies that need to be provided.
So the client can do a call to Api try update, if client got this error response with this error code and the content is these dependencies, the client can do automation with these dependencies.
Is it possible to do it?
Because I tried to use CreateErrorResponse, but it doesn't let me supply a content like CreateResponse(statusCode, complexObject)....
Or what is the best practice to work with this?
You're not limited to use CreateErrorResponse. It's just there to ease the job done by using already provided HttpError class:
http://msdn.microsoft.com/en-us/library/system.web.http.httperror%28v=vs.108%29.aspx
This class can contain additional set of key/value pairs that can be sent in response body.
However, you can always define your own error class (i.e. ApiError) that will contain exact data that you need, and then return that class by calling, i.e.:
Request.CreateResponse(HttpStatusCode.BadRequest, error);
Where error is instance of your ApiError class.
What is the best practice with regard to sending error responses in a JSON web service? I have seen it done several ways and wanted to know whether there were any agreed-upon standards or best practices among the choices.
I've seen it done where the response includes indication of success or failure as well as the data to be returned or a suitable error message, e.g.
[{'success':true, 'data':{...}]
[{'success':false, 'data':{'message':'error'}]
But I've also seen examples where the JSON object only includes data, and the service uses the normal HTTP error codes to indicate a problem (403, 404, 500, etc). (This is how the Twitter API does it.)
Is there a "right" way to do this, or is it just a matter of style? Is the latter method more "RESTful?"
In a "RESTful" approach, the primary error response is indicated by an appropriate status code (4xx/5xx).
Your message should provide addtional, application-specific hints on how to recover from the error. This may include human-readable representations of the error that has occured or some kind of more technical indicator (i.e. providing an Exception class name).
For being generic, keep to a fix syntax for your error messages. This allows you to introduce new error messages withour breaking the clients.
Use the appropriate HTTP codes and put what you now call "data" as the body of the response. This is the only correcty RESTful way to make the API users aware of an error.
Just doing this will not make your API RESTful, but not doing it will surely make your API non RESTful.
An example of well-used HTTP status codes for errors is in the Dropbox v1 API reference, have a look at the "Errors" sections under each method, they explain which error codes you should expect and what is the associated meaning in that particular method.
We are in the middle of a ongoing discussion about how to handle REST exceptions.
Response Content type : JSON
Two solutions we have:
Throw all the unchecked exceptions as a JSON response.
Send Request Invalid Response code.
Arguments:
When its a error, why return JSON? Just send a invalid response code.
Counter Argument:
Response code are too technical to handle for normal developers.
Whats your say??
For a JSON API I recently developed I do both. I always respond with valid JSON (well, assuming I respond at all). If I detect an invalid request, I use status 400. If I detect a server error (which I don't believe is caused by an invalid request), I use a 5xx status. The JSON object contains a special key that is only set for errors, with a string value.
I think this is a good solution that respects REST principles, and can be used in multiple ways. The same solution is used by some other JSON APIs, such as Yahoo Search. Try http://search.yahooapis.com/ImageSearchService/V1/imageSearch?appid=YahooDemo&output=json .
Use error codes like for HTTP. So 50* for any exception cause by some internal problem. And 40* for bad arguments. Avoid using your own defined codes as far as its possible. The idea is to have a "uniform" interface.
In general.
204 for success without sending any content
200 for success with a json representation of the resource
And if its not a successful operation return appropriate response code. You can choose to optionally return a json. To simplify things you can have a common format (json) for all error responses.
http://en.wikipedia.org/wiki/REST is a must read before you freeze on your api specs.