mattboon · November 14, 2012 15:01 · Nov 14, 2012
diff --git a/gistfile1.php b/gistfile1.php
@@ -0,0 +1,57 @@
+<?php
+
+// Add past/future events filter
+add_action( 'restrict_manage_posts', 'my_add_past_prev_filter' );
+function my_add_past_prev_filter() {
+	global $typenow;
+	// get our time period filter (if applied)
+	$time_period = $_GET['time_period'];
+
+	// set our select options
+	$future_option = '<option value="future">Future events</option>';
+	$past_option = '<option value="past">Past events</option>';
+
+	// test for selected option
+	if($time_period=='future') {
+		$future_option = '<option value="future" selected="selected">Future events</option>';
+	}
+	elseif($time_period=='past') {
+		$past_option = '<option value="past" selected="selected">Past events</option>';
+	}
+
+	// output additional filter
+	if( $typenow != "post" && $typenow != "page" && $typenow == "event" ) {
+		echo '<select name="time_period" id="time_period" class="postform">';
+		echo '<option value="all">All events</option>';
+		echo $future_option;
+		echo $past_option;
+		echo '</select>';
+	}
+}
+
+// If filter is set, change the query
+add_filter( 'parse_query', 'sort_events_by_past_prev_filter' );
+function sort_events_by_past_prev_filter($query) {
+    global $pagenow;
+	// get our time period filter (if applied)
+	$time_period = $_GET['time_period'];
+    if (is_admin() && $pagenow=='edit.php' &&
+        isset($_GET['post_type']) && $_GET['post_type']=='event' && 
+        isset($_GET['time_period']) && $_GET['time_period'] !='all')  {
+
+        // amend the query
+        if($time_period=='future') {
+	        $query->query_vars['meta_key'] = 'event_date';
+	        $query->query_vars['meta_value'] = date("Y-m-d");
+	        $query->query_vars['meta_compare'] = '>=';
+        }
+        elseif($time_period=='past') {
+	        $query->query_vars['meta_key'] = 'event_date';
+	        $query->query_vars['meta_value'] = date("Y-m-d");
+	        $query->query_vars['meta_compare'] = '<=';
+        }
+
+    }
+}
+
+?>