Code to download an image without having to right click a link?

[w33nie]

I was wondering what I would need to do to make a link, when clicked, download an image with the Save As dialog box, instead of just loading the image inside the browser.
I know that MIME edit would be able to do this for my browser, but I want it scripted into my web site, because I can't tell all of my users to edit their browser's settings

I don't want to have to right click the link & click save as,
and I don't want to have to zip the file.

& I was told a server side language should be able to do it.

[Markus]

scroll down to the part about content disposition

[w33nie]

How do I get that in an html link though?

[Atli]

Hi.

Yes, this can be done using PHP.

PHP can suggest to the browser that the "page" should be downloaded as a specified file type rather than displayed as HTML markup.
Note that not all browsers are smart enough to accept this, but most of the major once are. (Last time I checked, of all the browsers I usually check my codes on, only Apple's Safari had some issues with this)
(EDIT: Just checked it and it appears that they have fixed it :P)

This is done, as Markus' link pointed out, via the header() function.
It sets HTTP headers, which are sent as directions to the browser, specifying a number of things, amongst which are the file name and type.

Try something like:
[code=php]
<?php
$fileToSend = "myImage.jp g";

// Set the headers, telling browsers that this is a JPEG image
// and that it is called "myImage.jp g"
header('Content-type: image/jpeg');
header('Content-Disposition: attachment; filename="myIma ge.jpg"');

// Send along the file size, just to be thorough.
header("Content-Length: ". file_size($file ToSend));

// Send the contents of the file
readfile($fileT oSend);
?>
[/code]
Any decent browser will accept this as an image, and either display it as such or open a download dialog.

[Markus]

Using what atli said, you'd pass an id through a link

http://example.com/imagedownload.php?id=image_name.jpg

Then on the imagedownload.p hp you'd have atli's coding, but you'd substitute the "myImage.jp g" with the actual image name, and you'd also have to supply the MIME type.

[Atli]

To add a bit to my earlier post...
I did a little testing on this while back and found that setting the following headers will open up a download dialog in all of the major browsers. (IE, Firefox, Opera and Safari... at least)
[code=php]
header("Pragma: public");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Cache-Control: private",false) ;
header("Content-Disposition: attachment; filename=\"".ba sename($filenam e)."\";" );
header("Content-Transfer-Encoding: binary");
header("Content-Type: PHP Generated Data");
header("Content-Length: ".filesize($fil ename));
[/code]
The Content-Type is set to an invalid type ("PHP Generated Data") on purpose, as all of the browsers I have tested this on automatically detect the file type when given an invalid Content-type.

The various cache-control headers are set in an attempt to force the browser to always download the image, rather than displaying any cached version.

[Markus]

To add a bit to my earlier post...
I did a little testing on this while back and found that setting the following headers will open up a download dialog in all of the major browsers. (IE, Firefox, Opera and Safari... at least)
[code=php]
header("Pragma: public");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Cache-Control: private",false) ;
header("Content-Disposition: attachment; filename=\"".ba sename($filenam e)."\";" );
header("Content-Transfer-Encoding: binary");
header("Content-Type: PHP Generated Data");
header("Content-Length: ".filesize($fil ename));
[/code]
The Content-Type is set to an invalid type ("PHP Generated Data") on purpose, as all of the browsers I have tested this on automatically detect the file type when given an invalid Content-type.

The various cache-control headers are set in an attempt to force the browser to always download the image, rather than displaying any cached version.

Thanks for extra info there, atli!
I'll remember that, as i hope the OP will.

Cheers.

[w33nie]

Great, thanks, I'll give this a whirl when I've got a bit of spare time.

[w33nie]

Hmm, okay, I'm sure the fact that didn't work has something to do with my poor attempt at it,

Here's the link that tries to start the download,
[html]
<a href="http://www.***.com/photos_download .php?id=<?php echo $photo_full; ?>" target="_blank" >
[/html]
and here's the PHP code on the download page,
[php]
$filename = $_GET['id'];
header("Pragma: public");
header("Cache-Control: must-revalidate, post-check=0, pre-check=0");
header("Cache-Control: private",false) ;
header("Content-Disposition: attachment; filename=\"".ba sename($filenam e)."\";" );
header("Content-Transfer-Encoding: binary");
header("Content-Type: PHP Generated Data");
header("Content-Length: ".filesize($fil ename));
[/php]

This code results in this link on the page itself,

http://www.****.com/images/button%20-%20photo%20-%20download.jpg

Once clicked, opens a blank page to download the file. Although this page takes about 20 seconds to bring up the download dialog. It does eventually download the correct file (or atleast correctly named), but only a 1kb unworking version of it.

[w33nie]

can anyone help?
...

[Markus]

can anyone help?
...

Hmm, content type: PHP Generated Data?

Try changing that to octet-stream

[Markus]

Hmm, content type: PHP Generated Data?

Try changing that to octet-stream

Or application/octet-stream

Not sure where the edit button has gone?

[w33nie]

No neither octet-stream or application/octet-stream worked,

& Just realised I made a mistake earlier with what the link ends up as,
it's actually this,
[html]www.***.com/photos_download .php?id=images/photos/France%20-%20Paris%20-%20Eiffel%20Tow er%20-%20Day%20-%2001%20-%20full.jpg[/html]

[Atli]

Try removing the path from the image name in your URL and add it in your code in stead. The extra / characters *may* cause some confusion.

Also, try it with an image that does not have spaces in the name. Spaces are represented by %20 in your URL. Don't know but that *may* be messing something up.

Changing the Content-Type should not have any effect. Any decent browser will automatically detect what it is downloading no matter what it says. (I've tested it! ^^)

[Atli]

Another thing I just noticed...

There isn't anything in the code you posted that prints the image data. Can we see that part to?