php - How can I create a download link of a PDF that does not require a right click?

Question

I am working on a website where the visitor should be able to download a pdf file. (There are three links to choose from but that is irrelevant) I wanted to know how to make it so that the visitor can simply click the link and not have to

right click > Save (target) As...

I am open to PHP and or Javascript solutions. Thanks.

EDIT: Can I use javascript to call the PHP and save the file via AJAX?

EDIT2: I used Nirmal's solution in the end, since it was the simplest to change for all three files. I didn't need to make 3 files for the three PDF's and I didn't need to hand code the switch. BalusC gets the check though since his/her code was up first and does the trick too.

Answer 1

All you basically need to do is to set the Content-Disposition header to attachment to get a 'Save As' dialogue. Here's a kickoff PHP example:

<?php
    header('Content-Type: application/pdf');
    header('Content-Disposition: attachment;filename="foo.pdf"');
    readfile('/path/to/foo.pdf');
?>

You can't and don't want to do this with Javascript.

Important note: due to a poor feature, in MSIE the default filename in 'Save As' dialogue won't be derived from the content-disposition header, it will instead be the last part of the pathinfo in the request URL. To workaround this, append the PDF filename to the link, e.g. http://example.com/pdf/foo.pdf. You can even make use of it in PHP to read the in the pathinfo specified PDF file. Here's a basic example of pdf.php:

<?php
    $file_name = $_SERVER['PATH_INFO'];
    $file = '/path/to/pdf/files' . $file_name;
    if (file_exists($file)) {
        header('Content-Type: application/pdf');
        header('Content-Disposition: attachment;filename="' . basename($file_name) . '"');
        header('Content-Length: ' . filesize($file));
        readfile($file);
    } else {
        header('HTTP/1.1 404 Not Found');
    }
?>

This however assumes that you've MultiViews on so that /pdf/ will go through this PHP file, or at least a RewriteRule from /pdf/ to /pdf.php/.

The major advantage of this approach is that you don't need to change the code whenever you want to add a new PDF file or change the PDF file name.

You can even make it more generic by automatically determining and setting the correct content type:

<?php
    $file_name = $_SERVER['PATH_INFO'];
    $file = '/path/to/all/files' . $file_name;
    if (file_exists($file)) {
        header('Content-Type: ' . mime_content_type($file_name));
        header('Content-Disposition: attachment;filename="' . basename($file_name) . '"');
        header('Content-Length: ' . filesize($file));
        readfile($file);
    } else {
        header('HTTP/1.1 404 Not Found');
    }
?>

Name it files.php or so and then you have a generic PHP downloader which you can access by for example http://example.com/files/foo.pdf, http://example.com/files/bar.zip, etcetera.

Hope this helps.