[Developers] Problems uploading images

[Coral Link]

Hello FreeBDevs:

So we finally got over the hump here; we fired up 'tcpflow' (awesome network
diagnostic tool, by the way, easier than tcpdump) to monitor the exchange
between the local system and freebase.

-The Broken-
Freebase's 'raw' upload url (sandbox.freebase.com/api/service/upload) only
accepts 'POST' requests but doesn't know how to deal with
multipart/form-data as a content type.  PHP/libcurl defaults its POST to
Content-Type: multipart/form-data,  and embeds the image inside of that
multipart envelope.  Below is the tcpflow output with the broken code, minus
some extraneous stuff (192.168.0.150 is the local system, 208.068.108.121 is
sandbox.freebase.com):

192.168.000.150.46220-208.068.108.121.00080: POST /api/service/upload
HTTP/1.1
Content-Type: image/gif
Content-Length: 13365
Content-Length: 13555
Expect: 100-continue

192.168.000.150.46220-208.068.108.121.00080: Content-Type:
multipart/form-data; boundary=----------------------------b8245f93a0cb
------------------------------b8245f93a0cb
Content-Disposition: form-data; name="filename"; filename="CORAL.gif"
Content-Type: image/gif


192.168.000.150.46220-208.068.108.121.00080:
GIF89a+.........).X.T.r....-.w.\.r....1{..d>3o;..5wV.l~3..,g.....;<Image
Data Here>
192.168.000.150.46220-208.068.108.121.00080:
------------------------------b8245f93a0cb--

208.068.108.121.00080-192.168.000.150.46220: HTTP/1.0 400 Bad Request


***This lead to the cryptic "cannot identify image file" response from the
freebase server.***


-The Fix-
Straightforward, but there are no examples of this I could find in Google to
use CURLOPT_READDATA instead of CURLOPT_POSTFIELDS:

Replace one line:
   curl_setopt($request, CURLOPT_POSTFIELDS,$content);

With these two lines, dropping the @ from the front of the file name:
    $fp = fopen ($content, "r");
    curl_setopt($request, CURLOPT_READDATA, $fp);


-The New-
The working interaction is as follows, note there is no mention of
multiparts:

192.168.000.150.59161-208.068.108.121.00080: POST /api/service/upload
HTTP/1.1
Content-Type: image/gif
Content-Length: 13365
Expect: 100-continue


192.168.000.150.59161-208.068.108.121.00080: GIF89a+............,.<Image
Data Here>
\.r....1{..d>3o;..5wV.l~3..,g.....;
208.068.108.121.00080-192.168.000.150.59161: HTTP/1.0 200 OK


Hope this leads to less pulled out hair for someone.

Regards,
Indy


On Dec 30, 2007 2:05 AM, Coral Link <corallink at gmail.com> wrote:

> Hi; I'm using PHP/LibCURL to upload images relevant to my topics.  I'm
> guessing its more of a PHP issue than Freebase, but hopefully someone will
> indulge a helping hand.
>
> I'm running into this problem when uploading an image:
>
> { "status": "400 Application Error", "code": "/api/status/error",
> "messages": [ { "info": { "exception": "cannot identify image file" },
> "message": "Invalid image file.", "code":
> "/api/status/error/upload/invalid_image_data" } ] }
>
> When I run the following:
>
> $content="@/hole/www/corallink.com/freebase/files/uwlImage/9202a8c04000641f80000000060b61a7/CORAL.gif";
> $type="image/gif";
>
> $request = curl_init($url);
> curl_setopt($request, CURLOPT_COOKIEFILE, $cookiejarfile);  //get some
> cookies
> curl_setopt($request, CURLOPT_POST, 1);
> curl_setopt($request, CURLOPT_HTTPHEADER, array("X-Metaweb-Request: TRUE",
> "Content-Type: ".$type));
> curl_setopt($request, CURLOPT_POSTFIELDS,$content);
>
> // Return the result instead of printing it out.
> curl_setopt($request, CURLOPT_RETURNTRANSFER, TRUE);
> curl_setopt($request, CURLOPT_COOKIE, $credentials);
>
> // Now fetch the URL
> $responsetext = curl_exec($request);
> curl_close($request);
>
>
> This same code works great for uploading documents for the description in
> /common/topic.  I've tried variations where I've made
> $content=array("file"=>"@ filename.gif"), which uploaded data, but
> Freebase tagged it as media_type 'octet/stream'.  Any suggestions will be
> appreciated.
>
> Thank you and kind regards,
> Indy
>
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