Add paging to Walker class. Props hailin. fixes #7743

git-svn-id: http://svn.automattic.com/wordpress/trunk@8939 1a063a9b-81f0-0310-95a4-ce76da25c4cd
This commit is contained in:
ryan 2008-09-19 06:59:47 +00:00
parent 0889951393
commit 76718590f8

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@ -485,7 +485,7 @@ class WP {
/**
* PHP4 Constructor - Does nothing.
*
* Call main() method when ready to run setup.
* Call main() method when ready to run setup.
*
* @since 2.0.0
*
@ -818,7 +818,7 @@ class Walker {
$id = $element->$id_field;
// descend only the depth is right and there are chilrens for this element
// descend only when the depth is right and there are childrens for this element
if ( ($max_depth == 0 || $max_depth > $depth+1 ) && isset( $children_elements[$id]) ) {
foreach( $children_elements[ $id ] as $child ){
@ -917,8 +917,8 @@ class Walker {
foreach ( $top_level_elements as $e )
$this->display_element( $e, $children_elements, $max_depth, 0, $args, $output );
/*
* if we are displaying all levels, and remaining children_elements is not empty,
/*
* 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 ) && count( $children_elements ) > 0 ) {
@ -930,6 +930,109 @@ class Walker {
return $output;
}
/**
* paged_walk() - produce a page of nested elements
*
* Given an array of hierarchical elements, the maximum depth, a specific page number,
* and number of elements per page, this function first determines all top level root elements
* belonging to that page, then lists them and all of their children in hierarchical order.
*
* @package WordPress
* @since 2.7
* @param $max_depth = 0 means display all levels; $max_depth > 0 specifies the number of display levels.
* @param $page_num the specific page number, beginning with 1.
* @return XHTML of the specified page of elements
*/
function paged_walk( $elements, $max_depth, $page_num, $per_page ) {
/* sanity check */
if ( empty($elements) || $max_depth < 0 )
return '';
$args = array_slice( func_get_args(), 4 );
$output = '';
$id_field = $this->db_fields['id'];
$parent_field = $this->db_fields['parent'];
/*
* seperate elements into two buckets: top level and children elements
* children_elements is two dimensional array, eg.
* children_elements[10][] contains all sub-elements whose parent is 10.
*/
$top_level_elements = array();
$children_elements = array();
foreach ( $elements as $e) {
if ( 0 == $e->$parent_field )
$top_level_elements[] = $e;
else
$children_elements[ $e->$parent_field ][] = $e;
}
$count = -1;
$total_top = count( $top_level_elements );
if ( $page_num < 1 || $per_page < 0 ) {
$start = 0;
$end = $total_top;
} else {
$start = ( (int)$page_num - 1 ) * (int)$per_page;
$end = $start + $per_page;
}
foreach( $top_level_elements as $e ){
$count++;
//for the last page, need to unset earlier children in order to keep track of orphans
if ( $end >= $total_top && $count < $start )
$this->unset_children( $e, $children_elements );
if ( $count < $start )
continue;
if ( $count >= $end )
break;
$this->display_element( $e, $children_elements, $max_depth, 0, $args, $output );
}
if ( $end >= $total_top && count( $children_elements ) > 0 ){
$empty_array = array();
foreach ( $children_elements as $orphans )
foreach( $orphans as $op )
$this->display_element( $op, $empty_array, 1, 0, $args, $output );
}
return $output;
}
function get_number_of_root_elements( $elements ){
$num = 0;
$parent_field = $this->db_fields['parent'];
foreach ( $elements as $e) {
if ( 0 == $e->$parent_field )
$num++;
}
return $num;
}
// unset all the children for a given top level element
function unset_children( $e, &$children_elements ){
if ( !$e || !$children_elements )
return;
$id_field = $this->db_fields['id'];
$id = $e->$id_field;
foreach ( (array)$children_elements[$id] as $child )
$this->unset_children( $child, $children_elements );
unset( $children_elements[$id] );
}
}
/**