PHP implements generating a tree list from the results of database query

This article mainly introduces the method of PHP generating a tree list from the database query results. It involves the skills of PHP operating HTML elements to generate a tree list. It is of great practical value. Friends who need it can refer to it

The example in this article describes how PHP generates a tree list from database query results. The specific analysis is as follows:

This code can read data from the database to generate a tree list similar to the windows resource manager

', $name ? " name=\"$name\"" : '',
 $icon, $width, $height);
}
function display_directory($parent,$showdepth=0,$ancestors=false){
 global $child_nodes, $node_data, $last_child;
 reset($child_nodes[$parent]);
 $size = sizeof($child_nodes[$parent]);
 $lastindex = $size - 1;
 if (!$ancestors) {
 $ancestors = array();
 }
 $depth = sizeof($ancestors);
 printf( '
',
 $parent, $showdepth > 0 ? 'show' : 'hide');
 while (list($index, $node) = each($child_nodes[$parent])) {
 for ($i = 0; $i < $depth; $i++) {
 $up_parent = (int)$node_data[$ancestors[$i]][ 'parent'];
 $last_node_on_generation = $last_child[$up_parent];
 $uptree_node_on_generation = $ancestors[$i];
 if ($last_node_on_generation == $uptree_node_on_generation) {
 icon( "blank");
 } else {
 icon( "line");
 }
 }
 if ($child_nodes[$node]) {
 // has children, i.e. it is a folder
 $conn_icon = "plus";
 $expand = true;
 } else {
 $conn_icon = "join";
 $expand = false;
 }
 if ($index == $lastindex) {
 $conn_icon .= "bottom";
 } elseif ($depth == 0 && $index == 0) {
 $conn_icon .= "top";
 }
 if ($expand) {
 printf( "", $node);
 }
 icon($conn_icon, "connImg_$node");
 if ($expand) {
 print( "");
 }
 $icon = $node_data[$node][ 'icon'];
 if (!$icon) {
 $type = $node_data[$node][ 'type'];
 $icon = $GLOBALS[ 'dirent_icons'][$type];
 }
 icon($icon, "nodeImg_$node");
 $name = $node_data[$node][ 'name'];
 printf( '?%s', -1, $name, 10);
 if ($child_nodes[$node]) {
 $newdepth = $showdepth;
 if ($newdepth > 0) {
 $newdepth--;
 }
 $new_ancestors = $ancestors;
 $new_ancestors[] = $node;
 display_directory($node, $newdepth, $new_ancestors);
 }
 }
 print( "");
}
function setup_directory($parent, $maxdepth)
{
 global $dirent_icons, $child_nodes, $node_data, $last_child;
 $dirent_icons = sql_assoc('SELECT id,icon FROM dirent_types');
 $query = 'SELECT id,parent,type,icon,name '.
 'FROM directory '.
 'ORDER BY parent,name';
 $child_nodes = array();
 $node_data = array();
 $res = sql($query);
 while (list($id,$parent,$type,$icon,$name)=db_fetch_row($res)){
 $child_nodes[(int)$parent][] = $id;
 $node_data[$id] = array( 'id' => $id,
 'parent' => $parent,
 'type' => $type,
 'icon' => $icon,
 'name' => $name);
 $last_child[(int)$parent] = $id;
 }
}
?>

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