To update, I tested the following HTML in a valid XHTML Strict document on the W3 validation service. It came back valid so I can't see any issues in that area with adding it in as a fix.

<div class="resourcepdf">
<object data="test.pdf" type="application/pdf">
<param name="src" value="' . $fullurl . '" />Click to open <a href="test.pdf">PDF</a>
</object>
</div>

Edit: Forgot to actually mention which file I've made the change in...

Moodle/mod/resources/type/file/resource.class.php

Internet Explorer does not like the Object tag!!!

I've had similar problems with the Site Policy not displayng in IE, and had to change the Object to IFRAME to get it to work.

Possibly related to this issue... http://tracker.moodle.org/browse/MDL-14609

Just to update on this issue, the fix I mentioned above is still working brilliant on my Moodle installation for users.

Any time that I've reverted the code I get several IE users complaining about blank PDFs.

I can confirm that issue is still present on 1.9.2+ (current as of 3 weeks ago) with IE 6.0 on XP. Adding the line proposed by David Boyer fixes the issue (with no apparent side effects on FF 2.0.x and 3.0.x). We are going to test it with IE 7.0 on XP and Vista to confirm the proposed fix.

Thanks a lot David for your patch! It has saved us from much grief!

Iñaki.

We have just tested the proposed fix with IE 7.0 on XP and Vista (and also FF 3.0 on Vista) and everything works as expected.

So Nicolas, could you apply the proposed fix? If you are too busy, I can take care of it myself.

Iñaki.

Iñaki,

Yes please, that would be very good if you could do it.

Cheers

Can you check the flash embedding issue too

http://moodle.org/mod/forum/discuss.php?d=110178

You may need to add some other param tags in addition to that pdf tag

<param name="src" value="' . $fullurl . '" />

Oh, one more note:

this flash embedding problem of file mod/resource/type/file/resource.class.php
does not occur only with IE - it happens with all browsers.

It may happen with other media types too - we just have not tested all types with the latest resource.class.php

Still most likely the flash embedding problem is related to this pdf issue - and how paths ( $fullurl, $relativeurl etc ) are used in resource.class.php

The lines that Iñaki added to http://moodle.org/mod/forum/discuss.php?d=110178#p484613 seem to solve also the flash case. Thank you for testing, Iñaki!

Fixes commited into CVS (1.8, 1.9 and HEAD)

Thanks a lot to David Boyer, Jon Witts and Mauno Korpelainen for helping resolving this issue!

Iñaki.

Same applies to user/policy.php file when using certain versions of IE7 and a PDF in the site policy.

Added this line to the file.

— a/user/policy.php
+++ b/user/policy.php
@@ -45,6 +45,7 @@

echo '<div class="noticebox">';
echo '<object id="policyframe" data="'.$CFG->sitepolicy.'" type="'.$mimetype.'">';
+ echo '<param name="src" value="' . $CFG->sitepolicy . '" />';
// we can not use our popups here, because the url may be arbitrary, see MDL-9823
echo '<a href="'.$CFG->sitepolicy.'" onclick="this.target=\'_blank\'">'.$strpolicyagreementclick.'</a>';
echo '</object></div>';

The file this fix was in appears to have been removed in the time since this bug was fixed. The replacement code isn't putting anything like
<param name="src" value="' . $fullurl . '" />
inside the object tag. Not sure why this was removed however I am able to view embedded pdfs in IE 6, 7 and 8. Closing.