Changeset 6384

Timestamp:

12/14/2007 09:46:52 PM (18 years ago)

Author:

ryan

Message:

Faster page and cat walker. Props hailin. see #5458

File:

• trunk/wp-includes/classes.php (modified) (2 diffs)

trunk/wp-includes/classes.php

@@ -387 +387 @@
 }
 
-
-// A class for displaying various tree-like structures. Extend the Walker class to use it, see examples at the bottom
-
+/* 
+ * A class for displaying various tree-like structures. 
+ * Extend the Walker class to use it, see examples at the bottom
+ */
 class Walker {
     var $tree_type;
@@ -400 +401 @@
     function end_el($output)    { return $output; }
 
-    function walk($elements, $to_depth) {
-        $args = array_slice(func_get_args(), 2); $parents = array(); $depth = 1; $previous_element = ''; $output = '';
-
-        //padding at the end
-        $last_element->post_parent = 0;
-        $last_element->post_id = 0;
-        $elements[] = $last_element;
-
+    /*
+     * display one element if the element doesn't have any children
+     * otherwise, display the element and its children
+     */
+    function display_element( $element, &$children_elements, $max_depth, $depth=0, $args, $output ) {
+    
+        if ( !$element)
+            return $output; 
+        
+        if ( $max_depth != 0 ) {
+            if ($depth >= $max_depth)
+                return $output; 
+        }
+    
         $id_field = $this->db_fields['id'];
         $parent_field = $this->db_fields['parent'];
-
-        $flat = ($to_depth == -1) ? true : false;
-
-        foreach ( $elements as $element ) {
-            // If flat, start and end the element and skip the level checks.
-            if ( $flat) {
-                // Start the element.
-                if ( isset($element->$id_field) && $element->$id_field != 0 ) {
-                    $cb_args = array_merge( array($output, $element, $depth - 1), $args);
-                    $output = call_user_func_array(array(&$this, 'start_el'), $cb_args);
-                }
-
-                // End the element.
-                if ( isset($element->$id_field) && $element->$id_field != 0 ) {
-                    $cb_args = array_merge( array($output, $element, $depth - 1), $args);
-                    $output = call_user_func_array(array(&$this, 'end_el'), $cb_args);
-                }
-
-                continue;
+    
+        //display this element
+        $cb_args = array_merge( array($output, $element, $depth), $args);
+        $output = call_user_func_array(array(&$this, 'start_el'), $cb_args);
+
+        if ( !$children_elements ) {
+            //close off this element
+            $cb_args = array_merge( array($output, $element, $depth), $args);
+            $output = call_user_func_array(array(&$this, 'end_el'), $cb_args);
+            return $output; 
+        }
+    
+        for ( $i = 0; $i < sizeof( $children_elements ); $i++ ) {
+            $child = $children_elements[$i];
+            
+            if ( $child->$parent_field == $element->$id_field ) {
+                
+                array_splice( $children_elements, $i, 1 ); 
+                
+                //start the child delimiter
+                $cb_args = array_merge( array($output, $depth), $args);
+                $output = call_user_func_array(array(&$this, 'start_lvl'), $cb_args);
+                
+                $output = $this->display_element( $child, $children_elements, $max_depth, $depth + 1, $args, $output );
+                
+                //end the child delimiter
+                $cb_args = array_merge( array($output, $depth), $args);
+                $output = call_user_func_array(array(&$this, 'end_lvl'), $cb_args);
+                $i--; 
             }
-
-            // Walk the tree.
-            if ( !empty($previous_element) && ($element->$parent_field == $previous_element->$id_field) ) {
-                // Previous element is my parent. Descend a level.
-                array_unshift($parents, $previous_element);
-                if ( !$to_depth || ($depth < $to_depth) ) { //only descend if we're below $to_depth
-                    $cb_args = array_merge( array($output, $depth), $args);
-                    $output = call_user_func_array(array(&$this, 'start_lvl'), $cb_args);
-                } else if ( $to_depth && $depth == $to_depth  ) {  // If we've reached depth, end the previous element.
-                    $cb_args = array_merge( array($output, $previous_element, $depth), $args);
-                    $output = call_user_func_array(array(&$this, 'end_el'), $cb_args);
-                }
-                $depth++; //always do this so when we start the element further down, we know where we are
-            } else if ( $element->$parent_field == $previous_element->$parent_field) {
-                // On the same level as previous element.
-                if ( !$to_depth || ($depth <= $to_depth) ) {
-                    $cb_args = array_merge( array($output, $previous_element, $depth - 1), $args);
-                    $output = call_user_func_array(array(&$this, 'end_el'), $cb_args);
-                }
-            } else if ( $depth > 1 ) {
-                // Ascend one or more levels.
-                if ( !$to_depth || ($depth <= $to_depth) ) {
-                    $cb_args = array_merge( array($output, $previous_element, $depth - 1), $args);
-                    $output = call_user_func_array(array(&$this, 'end_el'), $cb_args);
-                }
-
-                while ( $parent = array_shift($parents) ) {
-                    $depth--;
-                    if ( !$to_depth || ($depth < $to_depth) ) {
-                        $cb_args = array_merge( array($output, $depth), $args);
-                        $output = call_user_func_array(array(&$this, 'end_lvl'), $cb_args);
-                        $cb_args = array_merge( array($output, $parent, $depth - 1), $args);
-                        $output = call_user_func_array(array(&$this, 'end_el'), $cb_args);
-                    }
-                    if ( $element->$parent_field == $parents[0]->$id_field ) {
-                        break;
-                    }
-                }
-            } else if ( !empty($previous_element) ) {
-                // Close off previous element.
-                if ( !$to_depth || ($depth <= $to_depth) ) {
-                    $cb_args = array_merge( array($output, $previous_element, $depth - 1), $args);
-                    $output = call_user_func_array(array(&$this, 'end_el'), $cb_args);
-                }
-            }
-
-            // Start the element.
-            if ( !$to_depth || ($depth <= $to_depth) ) {
-                if ( $element->$id_field != 0 ) {
-                    $cb_args = array_merge( array($output, $element, $depth - 1), $args);
-                    $output = call_user_func_array(array(&$this, 'start_el'), $cb_args);
-                }
-            }
-
-            $previous_element = $element;
-        }
-
-        return $output;
+        }
+        return $output; 
+    }
+
+    /*
+    * displays array of elements hierarchically
+    * max_depth = -1 means flatly display every element 
+    * max_depth = 0  means display all levels 
+    * max_depth > 0  specifies the number of display levels. 
+    */
+    function walk( $elements, $max_depth) {
+    
+        $args = array_slice(func_get_args(), 2);
+        $output = '';
+
+        $id_field = $this->db_fields['id'];
+        $parent_field = $this->db_fields['parent'];
+
+        $flat = ($max_depth == -1) ? true : false;
+        if ( $flat ) {
+            $empty_array = array(); 
+            foreach ( $elements as $e )     
+                $output = $this->display_element( $e, $empty_array, 1, 0, $args, $output );
+            return $output; 
+        }
+        
+        /* 
+         * need to display in hierarchical order 
+         * splice elements into two buckets: those without parent and those with parent
+         */
+    
+        $top_level_elements = array();
+        $children_elements  = array();
+    
+        foreach ( $elements as $e) {
+            if ( 0 == $e->$parent_field )
+                $top_level_elements[] = $e; 
+            else
+                $children_elements[] = $e; 
+        }
+    
+        foreach ( $top_level_elements as $e )
+            $output = $this->display_element( $e, $children_elements, $max_depth, 0, $args, $output );
+            
+        /* 
+        * if we are displaying all levels, and remaining children_elements is not empty, 
+        * then we got orphans, which should be displayed regardless
+        */
+        if ( ( $max_depth == 0 ) && sizeof( $children_elements ) > 0 ) {
+            $empty_array = array(); 
+            foreach ( $children_elements as $orphan_e )
+                $output = $this->display_element( $orphan_e, $empty_array, 1, 0, $args, $output );
+         }
+         return $output;
     }
 }