OK, I've gone through the files looking for the hacks, and I don't have to worry about the wpbook.php file. The only change I made to that was what you suggested here, and I'm sure you put that in already.
I assume that my modified app template will still work from one WPbook release to another. Is that reasonable?
If so, then it's only the publish_to_facebook.php file where I have to be careful.
Here is a hack that I recommend you do add to publish_to_facebook.php for everybody:
// your original line 55:
// $wpbook_description = stripslashes(wp_filter_nohtml_kses(apply_filters('the_content',$my_post->post_content)));
// replacement code begins:
$JLW_description = apply_filters('the_content',$my_post->post_content);
$JLW_beforeMore = strpos($JLW_description,'<!--more-->') ;
if ( $JLW_beforeMore === false) { }
else {
$JLW_description = substr( $JLW_description, 0, $JLW_beforeMore ) . '...' ;
}
$wpbook_description = stripslashes(wp_filter_nohtml_kses( $JLW_description ));
// replacement code ends.
This makes WPbook respect the <!--more--> tag, as described in the installation instructions.
My other suggestion would be to pull any echoed text out into a language file. For example, somewhere around line 95, I have:
$action_links = array( array('text' => 'Rate · Read More', // JLW: originally was 'Read More'
If an admin could specify strings like these in a language file outside of publish_to_facebook.php, upgrades would be easier. It would especially help translators.
(I changed that text because my customization of the app template shows the Five-Star-Ratings plugin's rating of each post. Although it is visible on both the Wall and the App's category/tag/archive lists, you can't actually vote with the stars until viewing the whole post in the App.)
The other changes were also of that nature. So if the READ MORE tag is respected and the default strings are in a language file, I'd never be scared of upgrades.
Thanks again for a great plugin!