[Developers] mqlread http response header (content-type)

[Alec Flett]

Below is the long answer. The short answer is "the docs are out of  
date" :)

Much of the reasoning is practical -  application/json made it really  
hard to debug because browsers refuse to display application/json  
directly in the browser - application/json makes the browser prompt  
the user with a save/launch dialog. Not to mention that certain APIs  
(like image upload) can only be run in IFRAMEs in the browser, which  
means those APIs must return text/plain so they can be intercepted and  
parsed by JS.

When you're developing against a JSON API, it's much easier to see  
this stuff visible instead of launching a separate app like notepad /  
textedit.

When considering the above, there didn't seem to be any actual value  
in making it return application/json - nobody we talked to could come  
up with a reason that making it application/json would be any better  
than it returning text/plain

Augusto - is there a particular reason you need application/json?

Alec

On Sep 18, 2008, at 11:53 AM, Christine Weibel wrote:

>
> Hmm.  mqlread did used to return a content-type of application/json,  
> but there was a deliberate change to text/plain a while ago.  it is  
> my recollection that was done for some browser compatibility issue?   
> perhaps alecf remembers this.
>
>
>
> ----- Original Message -----
> From: "Augusto Callejas" <acallejas at appliedminds.com>
> To: "For discussions about MQL, Freebase API and apps built on  
> Freebase" <developers at freebase.com>
> Sent: Thursday, September 18, 2008 11:39:29 AM (GMT-0800) America/ 
> Los_Angeles
> Subject: Re: [Developers] mqlread http response header (content-type)
>
> according to the documenation:
>
> http://www.freebase.com/view/guid/9202a8c04000641f800000000544e139
>
> =====
> 4.2.2. mqlread Output
>
> mqlread returns an HTTP response with a Content-Type header of
> application/json (or text/plain if the callback parameter was  
> specified).
> The body of the response is a JSON-serialized envelope object that  
> holds a
> MQL result object (or objects if multiple queries were submitted). The
> format of mqlread response envelopes is specified in Section 4.2.3
> =====
>
> however i did not specify a callback parameter, so how do i get  
> mqlread to
> return its response as "application/json" and not text/plain;
> charset="utf-8".
>
> thanks,
> augusto.
>
>
> On 9/17/08 9:36 AM, "Augusto Callejas" <acallejas at appliedminds.com>  
> wrote:
>
>> hi-
>>
>> when i perform a mqlread query, i get back HTTP response headers  
>> that look
>> like:
>>
>> =====
>> Date: Wed, 17 Sep 2008 00:51:35 GMT
>> ,
>> Server: Apache
>> ,
>> X-Metaweb-Success: 1/1
>> ,
>> Content-Length: 35616
>> ,
>> Content-Type: text/plain; charset="utf-8"
>> ,
>> ...
>> Connection: Keep-Alive
>> =====
>>
>>
>> shouldn't the "Content-Type" header value be "application/json"?
>>
>> http://www.iana.org/assignments/media-types/application/
>>
>> i'm having a problem with the 'charset="utf-8"' in the header.
>> the java http client library that i'm using (
>> http://hc.apache.org/httpclient-3.x/) reads the response (see example
>> below), and decodes any unicode characters (ie. /u001a) into their  
>> actual
>> character value.  however, this is before i get a chance to decode  
>> it in my
>> json library.  however, the unicode characters have already been  
>> decoded at
>> the http level, but not at the json level.
>>
>> any thoughts?
>>
>> thanks,
>> augusto.
>>
>>
>> query
>> =====
>> {"q":{"query":
>> {
>>  "master_property" : "/type/object/name",
>>  "operation" : "delete",
>>  "source" : {
>>    "guid" : "#9202a8c04000641f8000000006e31736"
>>  },
>>  "target_value" : {
>>    "value" : null
>>  },
>>  "timestamp" : "2008-08-30T18:56:23.0000Z",
>>  "type" : "/type/link",
>>  "valid" : null
>> }
>> }}
>> =====
>>
>>
>> response
>> =====
>> {
>>  "master_property" : "/type/object/name",
>>  "operation" : "delete",
>>  "source" : {
>>    "guid" : "#9202a8c04000641f8000000006e31736"
>>  },
>>  "target_value" : {
>>    "value" : "Friesengeist 2: Regelm\u001aässige Zerstö\u001arungen"
>>  },
>>  "timestamp" : "2008-08-30T18:56:23.0000Z",
>>  "type" : "/type/link",
>>  "valid" : null
>> }
>> =====
>>
>>
>> _______________________________________________
>> Developers mailing list
>> Developers at freebase.com
>> http://lists.freebase.com/mailman/listinfo/developers
>
>
> _______________________________________________
> Developers mailing list
> Developers at freebase.com
> http://lists.freebase.com/mailman/listinfo/developers
>