attempt to save the same custom meta for blog, news and event posts, then sort a feed containing all of these by the meta

gistfile1.txt

/*** Add Post Date Metabox */
function my_postdatemeta_init()
{

	add_meta_box('env_post_date_meta', 'Admin Meta', 'env_post_date_meta', 'post', 'normal', 'low');
	add_meta_box('env_post_date_meta', 'Admin Meta', 'env_post_date_meta', 'news', 'normal', 'low');
	add_meta_box('env_event_date_meta', 'Admin Meta', 'env_event_date_meta', 'ai1ec_event', 'normal', 'low');
}
add_action('admin_init','my_postdatemeta_init');

/*** The Post Date Metabox */
function env_post_date_meta() {
    global $post;
 
    /* Noncename needed to verify where the data originated */
    echo '<input type="hidden" name="envmeta_noncename" id="envmeta_noncename" value="' .
    wp_create_nonce( plugin_basename(__FILE__) ) . '" />';
 
    /* Get the location data if its already been entered */
    $env_post_date_meta = get_post_meta($post->ID, '_post_date_meta', true);
 
    /* Echo out the field */
    	echo '<p>For admin purposes. <strong>DO NOT USE</strong></p>';
    	echo '<input type="text" name="_post_date_meta" value="' . $env_post_date_meta  . '" class="widefat" />';
}

/*** Save the Metabox Data */ 
function env_save_post_date_meta($post_id, $post) {
 
    /* verify this came from the our screen and with proper authorization, */
    /* because save_post can be triggered at other times */
    if ( !wp_verify_nonce( $_POST['envmeta_noncename'], plugin_basename(__FILE__) )) {
    return $post->ID;
    }
 
    /* Is the user allowed to edit the post or page? */
    if ( !current_user_can( 'edit_post', $post->ID ))
        return $post->ID;
 
    /* OK, we're authenticated: we need to find and save the data */
    /* We'll put it into an array to make it easier to loop though. */
 
    $post_date_meta['_post_date_meta'] = $post->post_date;
 
    /* Add values of $events_meta as custom fields */
 
    foreach ($post_date_meta as $key => $value) { /* Cycle through the $home_meta array!  */
        if( $post->post_type == 'revision' ) return; /* Don't store custom data twice  */
        $value = implode(',', (array)$value); /* If $value is an array, make it a CSV (unlikely)  */
        if(get_post_meta($post->ID, $key, FALSE)) { /* If the custom field already has a value */
            update_post_meta($post->ID, $key, $value);
        } else { /* If the custom field doesn't have a value */
            add_post_meta($post->ID, $key, $value);
        }
        if(!$value) delete_post_meta($post->ID, $key); /* Delete if blank */
    }
}
add_action('wp_insert_post', 'env_save_post_date_meta', 1, 2); // save the custom fields

/*** The Event Date Metabox */
function env_event_date_meta() {
    global $post;
 
    /* Noncename needed to verify where the data originated */
    echo '<input type="hidden" name="envmeta_noncename" id="envmeta_noncename" value="' .
    wp_create_nonce( plugin_basename(__FILE__) ) . '" />';
 
    /* Get the location data if its already been entered */
    $env_post_date_meta = get_post_meta($post->ID, '_post_date_meta', true);
 
    /* Echo out the field */
    	echo '<p>For admin purposes. <strong>DO NOT USE</strong></p>';
    	echo '<input type="text" name="_post_date_meta" value="' . $env_post_date_meta  . '" class="widefat" />';
}
/*** Save the Metabox Data */ 
function env_save_event_date_meta($post_id, $post) {
 
    /* verify this came from the our screen and with proper authorization, */
    /* because save_post can be triggered at other times */
    if ( !wp_verify_nonce( $_POST['envmeta_noncename'], plugin_basename(__FILE__) )) {
    return $post->ID;
    }
 
    /* Is the user allowed to edit the post or page? */
    if ( !current_user_can( 'edit_post', $post->ID ))
        return $post->ID;
 
    /* OK, we're authenticated: we need to find and save the data */
    /* We'll put it into an array to make it easier to loop though. */
 	global $wpdb;
 	$pID = $post->ID;
 	$event = $wpdb->get_var( $wpdb->prepare( "SELECT start FROM acM_ai1ec_events WHERE post_ID = '$pID'" ) );
    $post_date_meta['_post_date_meta'] = $event;
 
    /* Add values of $events_meta as custom fields */
 
    foreach ($post_date_meta as $key => $value) { /* Cycle through the $home_meta array!  */
        if( $post->post_type == 'revision' ) return; /* Don't store custom data twice  */
        $value = implode(',', (array)$value); /* If $value is an array, make it a CSV (unlikely)  */
        if(get_post_meta($post->ID, $key, FALSE)) { /* If the custom field already has a value */
            update_post_meta($post->ID, $key, $value);
        } else { /* If the custom field doesn't have a value */
            add_post_meta($post->ID, $key, $value);
        }
        if(!$value) delete_post_meta($post->ID, $key); /* Delete if blank */
    }
}
add_action('wp_insert_post', 'env_save_event_date_meta', 1, 2); // save the custom fields




/*** Function for displaying featured posts from multiple custom types in a short feed, no pagination */
function env_display_feed_from_types($the_type, $the_order, $the_number = 3, $orderby = 'date', $status = 'publish')
{	
	$args = array(
		'post_type' => ($the_type),
		'posts_per_page' => $the_number,
		'order' => $the_order, 
		'post_status' => ($status),
		'meta_query' => array( 
			array(
				'key' => '_home_feat', 
				'value' => 'on'
			),
			array(
				'key' => '_post_date_meta'
			) 
		),
		'meta_key' => '_post_date_meta',
		'orderby' => 'meta_value_num'
	);
	$my_posts = new WP_Query( $args );
	if( $my_posts->have_posts() ):
	echo '<ul class="short_feed">';
	while ( $my_posts->have_posts() ) : $my_posts->the_post();
			global $post;
			if (get_post_type($post->ID) == "ai1ec_event") { $ptype = "event"; $event = Ai1ec_Events_Helper::get_event($post->ID); } else if (get_post_type($post->ID) == "news") { $ptype = "news"; } else { $ptype = "blog"; } ?>
			<li class="post_items clear">
				<img src="<?php bloginfo('stylesheet_directory'); ?>/images/feat_<?php echo $ptype; ?>.jpg" alt="<?php echo $ptype; ?>" /> 
				<div class="p_data">
					<a href="<?php the_permalink() ?>" class="p_title"><span><?php the_title(); ?>  |</span>  <?php if ($ptype == "event") { echo $event->long_start_date; } else { the_time('m.d.y'); } ?></a>
					<?php the_excerpt(); ?>
				</div> 
			</li><!--post_items-->
		<?php endwhile; ?>
	</ul>
	<?php endif; wp_reset_postdata(); 
}