· Dec 7, 2021

Can't change content-type in REST response

I've never had a problem changing the content-type on a response using either %CSP.Page or %CSP.REST until now. No matter where I put the line to set the content-type to "application/json", it stubbornly emits a content-type of "text/html".

In OnPreHTTP: (I tried one at a time)
    do %response.SetHeader("content-type", "application/json") // didn't work

    set %response.ContentType = "text/plain" // didn't work

The same lines in OnProcessInput() didn't change the output content-type, either.

The class signature is 
Class HS.Local.VA.HS.DocRepo.Prefetch.Service.RESTService Extends (Ens.BusinessService, %CSP.REST)

I get the data I'm looking for back in JSON format the way I expected. My consuming app doesn't like the fact that content-type is always text/html.

I've written tons of CSP and never had a problem changing content-type. Not sure what's going on here.

Thanks in advance!!


Product version: HealthShare 2019.1
$ZV: Cache for Windows (x86-64) 2018.1.2 (Build 309_5_19491U) Tue Dec 10 2019 17:30:27 EST
Discussion (4)1
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FWIW, I tried curl as well with the same results

C:\Users\VHADURWestlJ>curl --verbose  -H "Accept: application/json" --basic --http1.1 --verbose --user myusername:mypassword http://localhost:57772/csp/prefetch-rest/smoketest
*   Trying ::1...
* Connected to localhost (::1) port 57772 (#0)
* Server auth using Basic with user 'bfarrell'
> GET /csp/prefetch-rest/smoketest HTTP/1.1
> Host: localhost:57772
> Authorization: Basic YmZhcnJlbGw6ejAwMTA2MTUr
> User-Agent: curl/7.55.1
> Accept: */*
< HTTP/1.1 200 OK
< Date: Tue, 07 Dec 2021 19:54:43 GMT
< Server: Apache
< EXPIRES: Thu, 29 Oct 1998 17:04:19 GMT
< CACHE-CONTROL: no-cache
< PRAGMA: no-cache
< SET-COOKIE: CSPSESSIONID=000100010000MIqK2mHTrn000000000000000000000000000000000001; path=/;
< Content-Type: text/html; charset=utf-8
"errors": [
"exception": "",
"messages": [
"recordset": [
"sessionId": "MIqK2mHTrn",
"smokeTest": "this is a smoke test with some fake JSON return",
"summary": "success"
}* Connection #0 to host localhost left intact

Hi Bill, I was facing a similar (but not identical) issue not too long ago where I was trying set %response.Status in my REST handler class, only to have a different status code reflected in the response to the client.

The issue ended up being that the request to the REST handler class that I was working on was being forwarded from another REST handler class that extends EnsLib.REST.Service rather than %CSP.REST.  The EnsLib REST handler works a little differently.  The user code is supposed to write the output to a response stream, with the response headers being set as attributes of the stream, rather than setting headers of %response directly.

So my question is, is your REST handler downstream from an EnsLib.REST.Service REST handler?  I also see that your REST handler extends Ens.BusinessService.  I wonder if something in that class is overriding your %response headers.  Is there any way you can test your class with that superclass removed?