combining html and on-the-fly images using Image::Magick

[Hagbone]

Oh wise ones ....

I have a

use Image::Magick;

question concerning creating thumbnails on the fly. I'm able to produce an on-the-fly thumbnails (snippet below), and an essential part of the code is using the proper Content-type line.

print "Content-type: image/gif\n\n";
binmode STDOUT;
$thumb->Write('gif:-');

The above works fine, but my question/problem has to do with how to structure a script so it will produce *both* html content and thumbnails images in one output session.

If I use

print "Content-type:text/html\n\n";
<code>

the html displays fine, but the images appear as binary code. If I use
+ the 
<code>
print "Content-type: image/gif\n\n";

The html will not display.

I've cobbled a work around by creating temporary thumbnail images, and pointing to them in the html code, but would really like to know if there is a way to do what I describe above using on-the-fly images.

All suggestions appreciated

[jeffa]

You could write a second CGI script that accepts a argument for the gif to display (say , display.cgi). The first script then simply creates HTML, and any reference to a dynamic image will look like:

<img src="/path/to/display.cgi?name=foo" alt="foo" />

But if you have a lot of these ... that's a lot of CGI hits on the server. I would consider 'bulk generating' the images via a cron job if server performance becomes an issue (unless they are very 'on the fly' of course).

Also, consider using CGI.pm's header method to simplify printing content headers:

usg CGI qw(header);

print header;
print header('image/gif');

jeffa

L-LL-L--L-LL-L--L-LL-L--
-R--R-RR-R--R-RR-R--R-RR
B--B--B--B--B--B--B--B--
H---H---H---H---H---H---
(the triplet paradiddle with high-hat)

[merlyn]

You might find some insight by reading my column on the subject.

-- Randal L. Schwartz, Perl hacker
Be sure to read my standard disclaimer if this is a reply.

[jepri]

To clarify jeffa's response, you can't do what you want to do. Images in html are just links that the browser automatically downloads. There is a separate connection for every image. So what you are doing is more or less right.

____________________
Jeremy
I didn't believe in evil until I dated it.

[revdiablo]

This is not entirely true. It is possible to literally embed an image into the source of a page in HTML. Check out Re: Incorporating On-The-Fly Graphics In CGI output for details.

[jepri]

That is indeed a cool trick, and is much needed, but I can't see any specs for it at w3c.org, which makes me think it is browser specific and therefore A Bad Thing, regardless of how cool it is.

(Standards are everything. Obey the w3c. The w3c is your friend.)

Update: the w3c has nothing to say on the matter, but the IETF does (as mentioned below in this thread). So yay to that. ____________________
Jeremy
I didn't believe in evil until I dated it.

[revdiablo]

You might want to check out Incorporating On-The-Fly Graphics In CGI output for some relevant discussion. In particular I enjoyed Re: Incorporating On-The-Fly Graphics In CGI output (as you can probably tell by my reply to that node).