Using image_tag and send_data

Rails
1

I am using image_tag to load an image that I’ve saved to the database
(using attachment_fu if you’re curious but that’s probably not
relevant here):

VIEW
<%= image_tag ‘/photo/get_image/5’ %>

CONTROLLER
def get_image
@photo=Photo.find(params[:id])
send_data(DbFile.find(@photo.db_file_id).data,
:type => @photo.content_type,
:file_name =>
@photo.filename,
:disposition => ‘inline’)
end

The images I’m saving are less than 100kb and easily handled by my
mysql column of db_file.data which is declared MEDIUMBLOB.

My problem is that the view works perfectly in production but not at
all in development – in development I just get a broken image graphic
with a box and a red x.

Any ideas on how to troubleshoot this? Since it doesn’t seem to be my
code (it works fine in production) I’m at a loss on how to figure this
out.

2

On Oct 8, 2:32 pm, Lastps [email protected] wrote:

I am using image_tag to load an image that I’ve saved to the database
(using attachment_fu if you’re curious but that’s probably not
relevant here):

I’d copy and paste that image link into the browser (ie yourserver,com/
photo/get_image/5) and see what the browser pulls out.

Fred

3

Thanks for the suggestion –
I get the same red box with the x.

On Oct 8, 8:47 am, Frederick C. [email protected]

4

On 8 Oct 2008, at 15:05, Lastps wrote:

Thanks for the suggestion –
I get the same red box with the x.

Do the logs indicate that an error occured ? If not and if you use the
tool of your choice to download the image, how do the bytes differ
from the bytes you would expect.

Fred

5

logs say that all is ok:
Sending data my_image.jpg
Completed in 0.09400 (10 reqs/sec) | Rendering: 0.00000 (0%) | DB:
0.08000 (85%) | 200 OK [http://localhost/photo/get_image/5]

Interesting question you ask about how do the bytes differ. I guess I
first need to find a “tool of my choice” other than my two browsers
(IE and Firefox) – any suggestions?

On Oct 8, 9:18 am, Frederick C. [email protected]

6

i guess that’s the point in that the browser is not displaying the
image – it is just displaying the error gif, ie, a box with a red x
in it indicating that i can’t load the image.

Fred, i really appreciate the time you’re dedicating here…

On Oct 8, 9:51 am, Frederick C. [email protected]

7

Just tried something else –
Changed disposition to “attachment” and used Firefox to successfully
download the file. When I tried to open the file (in GIMP) I received
these error messages:
– Premature end of JPEG file
– Invalid JPEG file structure: missing SOS marker
So, I guess attachment_fu is not saving the files properly to my
db_file table…

8

On 8 Oct 2008, at 15:47, Lastps wrote:

logs say that all is ok:
Sending data my_image.jpg
Completed in 0.09400 (10 reqs/sec) | Rendering: 0.00000 (0%) | DB:
0.08000 (85%) | 200 OK [http://localhost/photo/get_image/5]

Interesting question you ask about how do the bytes differ. I guess I
first need to find a “tool of my choice” other than my two browsers
(IE and Firefox) – any suggestions?

using the browser to save the image to disk would be one way.

Fred

9

Yes – seems like attachment_fu or mysql (?) might be truncating.
Weird though as the file size is not very large – just 10kb. In my
experience, truncation occurs because you are handling large files…

On Oct 8, 10:08 am, Frederick C. [email protected]

10

On 8 Oct 2008, at 16:00, Lastps wrote:

Just tried something else –
Changed disposition to “attachment” and used Firefox to successfully
download the file. When I tried to open the file (in GIMP) I received
these error messages:
– Premature end of JPEG file
– Invalid JPEG file structure: missing SOS marker
So, I guess attachment_fu is not saving the files properly to my
db_file table…

that sounds like its getting truncated.

Fred

11

On 8 Oct 2008, at 16:15, Lastps wrote:

Yes – seems like attachment_fu or mysql (?) might be truncating.
Weird though as the file size is not very large – just 10kb. In my
experience, truncation occurs because you are handling large files…

I suppose you need to pinpoint where it happens: before the image hit
your app, before attachment fu tried to save it, when mysql was given
the image, after retrieval from the database etc…

Fred

12

Yep – guess I’ll step through and research the various ways to check
the size of the data at each place. Thanks for your help!

On Oct 8, 10:20 am, Frederick C. [email protected]