It does not work anymore since GReader updated its layout.

It still works with "List View", but no longer with "Expanded View" (where a new tab/window is opened).

Edit the Script:
Line 100:

function catchEntryAdded(e)
{
var el=e.target;
if (el.nodeName=='DIV' && el.className.indexOf('entry')>-1)
{
if (el.className.indexOf('entry-actions')>-1)
{
// Expanding article in list view
addPreviewButton(el);
}
else if (getFirstElementMatchingClassName(el,'tbody','card-tbody'))
{
// Adding article in expanded view
addPreviewButton(getFirstElementMatchingClassName(el,'div','entry-container'));
}
}
}

change to:

function catchEntryAdded(e)
{
var el=e.target;
if (el.nodeName=='DIV' && el.className.indexOf('entry')>-1)
{
if (el.className.indexOf('entry-actions')>-1)
{
// Expanding article in list view
addPreviewButton(el);
}
else if (getFirstElementMatchingClassName(el,'div','card-bottom'))
{
// Adding article in expanded view
addPreviewButton(getFirstElementMatchingClassName(el,'div','entry-actions'));
}
}
}


many thanks for the code update. i love this script.
I didnt work for me unfortunately. It added a preview button next to Edit Tags, but Clicking ">>" doesnt open up the link in an iframe still.

hmm ignore me, its just worked, ace!
many thanks

thanks a lot, xx3734!

xx3734: works for me, too - thanks.

thx!! lets hope the main developer will add it too

Anyone else having a problem where Firefox is telling them that they have to turn off the pop-up blocker whenever they try to bring up a preview?

@blah no

The preview script works fine for me initially but after some time, all of a sudden Firefox starts telling me that I need to shut off my pop-up blocker option for any Google sites. The funny thing is that I already did this a while back. Any help on this would be appreciated since I love this userscript.

got it working with the help from @xx3734's patch.

Hi,
I can't seem to get this to work.
Where can I find the button to share in facebook? I can see the preview button, but it does not do anything when I press it. Just turns orange.

Is there a hotkey to use the "preview" button?

awesome, thanks! This is the functionality that prompted me to install Greasemonkey tonight -- I've been missing this from the Better GReader extension for ages... Now if I can just get it to automatically show the preview so I don't have to keep clicking that little button every time... :)

thanks for fix!