Fix for issue #291

[openemr.git] / library / classes / Tree.class.php

<?php

define("ROOT_TYPE_ID",1);
define("ROOT_TYPE_NAME",2);

/**
 * class Tree
 * This class is a clean implementation of a modified preorder tree traversal hierachy to relational model
 * Don't use this class directly as it won't work, extend it and set the $this->_table variable, currently
 * this class needs its own sequence per table. MPTT uses a lot of self referential parent child relationships
 * and having ids that are more or less sequential makes human reading, fixing and reconstruction much easier.
 */

class Tree {

        /*
        *       This is the name of the table this tree is stored in
        *       @var string
        */
        var $_table;
        
        /*
        *       This is a lookup table so that you can get a node name or parent id from its id
        *       @var array
        */
        var $_id_name;
        
        /*
        *       This is a db abstraction object compatible with ADODB
        *       @var object the constructor expects it to be available as $GLOBALS['adodb']['db']
        */
        var $_db;
        
        /*
        *       The constructor takes a value and a flag determining if the value is the id of a the desired root node or the name
        *       @param mixed $root name or id of desired root node
        *       @param int $root_type optional flag indicating if $root is a name or id, defaults to id
        */
        function __construct($root,$root_type = ROOT_TYPE_ID) {
                $this->_db = $GLOBALS['adodb']['db'];
                $this->_root = add_escape_custom($root);
                $this->_root_type = add_escape_custom($root_type);
                $this->load_tree();
        }
        
        function load_tree() {
          $root = $this->_root;
          $tree = array();
          $tree_tmp = array();
           
          //get the left and right value of the root node
          $sql = "SELECT * FROM " . $this->_table . " WHERE id='".$root."'";
          
          if ($this->root_type == ROOT_TYPE_NAME) {
                $sql = "SELECT * FROM " . $this->_table . " WHERE name='".$root."'";
          }
          $result = $this->_db->Execute($sql) or die("Error: " . $this->_db->ErrorMsg());
          $row = array();

          if($result && !$result->EOF) {
            $row = $result->fields;
          }
          else {
                $this->tree = array();
          }

          // start with an empty right stack
          $right = array();

          // now, retrieve all descendants of the root node
          $sql = "SELECT * FROM " . $this->_table . " WHERE lft BETWEEN " . $row['lft'] . " AND " . $row['rght'] . " ORDER BY parent,name ASC;";
          $result = $this->_db->Execute($sql);
          $this->_id_name = array();

   
          while ($result && !$result->EOF) {
            $ar = array();
            $row = $result->fields;
            
            //create a lookup table of id to name for every node that will end up in this tree, this is used
            //by the array building code below to find the chain of parents for each node

            // ADDED below by BM on 06-2009 to translate categories, if applicable
            if ($this->_table == "categories") {
              $this->_id_name[$row['id']] = array("id" => $row['id'], "name" => xl_document_category($row['name']), "parent" => $row['parent']);
            }
            else {
              $this->_id_name[$row['id']] = array("id" => $row['id'], "name" => $row['name'], "parent" => $row['parent']);
            }
                
            // only check stack if there is one
            if (count($right)>0) {
              // check if we should remove a node from the stack
              while ($right[count($right)-1]<$row['rght']) {
                array_pop($right);
              }
            }

                //set up necessary variables to then determine the chain of parents for each node
            $parent = $row['parent'];
            $loop = 0;
            
            //this is a string that gets evaled below to create the array representing the tree
            $ar_string = "[\"".($row['id']) ."\"] = \$row[\"value\"]";
            
            //if parent is 0 then the node has no parents, the number of nodes in the id_name lookup always includes any nodes
            //that could be the parent of any future node in the record set, the order is deterministic because of the algorithm
            while($parent != 0 && $loop < count($this->_id_name)) {
                  $ar_string = "[\"" . ($this->_id_name[$parent]['id']) . "\"]" . $ar_string;
                  $loop++;
                  $parent = $this->_id_name[$parent]['parent'];
                }
                
                $ar_string = '$ar' . $ar_string . ";";
                //echo $ar_string;

                //now eval the string to create the tree array
                //there must be a more efficient way to do this than eval?
                eval($ar_string);
                
                //merge the evaled array with all of the already exsiting tree elements, 
                //merge recursive is used so that no keys are replaced in other words a key
                //with a specific value will not be replace but instead that value will be turned into an array
                //consisting of the previous value and the new value
                $tree = array_merge_n($tree,$ar);
      
                // add this node to the stack
                $right[] = $row['rght'];
                $result->MoveNext();
          }
          
          $this->tree = $tree;
        }

        /*
        *       This function completely rebuilds a tree starting from parent to ensure that all of its preorder values 
        *       are integrous.
        *       Upside is that it fixes any kind of goofiness, downside is that it is recursive and consequently 
        *       exponentially expensive with the size of the tree.
        *       On adds and deletes the tree does dynamic updates as appropriate to maintain integrity of the algorithm,
        *       however you can still force it to do goofy things and afterwards you will need this function to fix it.
        *       If you need to do a huge number of adds or deletes it will be much faster to act directly on the db and then
        *       call this to fix the mess than to use the add and delete functions.
        *       @param int $parent id of the node you would like to rebuild all nodes below
        *       @param int $left optional proper left value of the node you are rebuilding below, then used recursively
        */
        function rebuild_tree($parent, $left = null) {
          
          //if no left is supplied assume the existing left is proper
          if ($left == null) {
            $sql = "SELECT lft FROM " . $this->_table . " WHERE id='" . $parent . "';";
            $result = $this->_db->Execute($sql) or die("Error: " . $this->_db->ErrorMsg());

            if($result && !$result->EOF) {
                $left = $result->fields['lft'];
            }
            else {
                //the node you are rebuilding below if goofed up and you didn't supply a proper value
                //nothing we can do so error
                die("Error: The node you are rebuilding from could not be found, please supply an existing node id.");
            }
          }
          // get all children of this node
          $sql = "SELECT id FROM " . $this->_table . " WHERE parent='" . $parent . "' ORDER BY id;";
          $result = $this->_db->Execute($sql) or die("Error: " . $this->_db->ErrorMsg());
                  
          // the right value of this node is the left value + 1
          $right = $left+1;
   
          while ($result && !$result->EOF) {
                $row = $result->fields;
                // recursive execution of this function for each
                // child of this node
                // $right is the current right value, which is
                // incremented by the rebuild_tree function
                $right = $this->rebuild_tree($row['id'], $right);
                $result->MoveNext();
          }

          // we've got the left value, and now that we've processed
          // the children of this node we also know the right value
          $sql = "UPDATE " . $this->_table . " SET lft=".$left.", rght=".$right." WHERE id='".$parent."';";
          //echo $sql . "<br>";
          $this->_db->Execute($sql) or die("Error: $sql" . $this->_db->ErrorMsg());

          // return the right value of this node + 1
          return $right+1;
        }

        
        /*
        *       Call this to add a new node to the tree
        *       @param int $parent id of the node you would like the new node to have as its parent
        *       @param string $name the name of the new node, it will be used to reference its value in the tree array
        *       @param string $value optional value this node is to contain
        *       @return int id of newly added node
        */
        function add_node($parent_id,$name,$value="") {
          
          $sql = "SELECT * from " . $this->_table . " where parent = '" . $parent_id . "' and name='" . $name . "'";
          $result = $this->_db->Execute($sql) or die("Error: " . $this->_db->ErrorMsg());
          
          if ($result && !$result->EOF) {
                die("You cannot add a node with the name '" . $name ."' because one already exists under parent " . $parent_id . "<br>");
          }
          
          $sql = "SELECT * from " . $this->_table . " where id = '" . $parent_id . "'";
          $result = $this->_db->Execute($sql) or die("Error: " . $this->_db->ErrorMsg());
          
          $next_right = 0;
          
          if ($result && !$result->EOF) {
            $next_right = $result->fields['rght'];
          }
   
          $sql = "UPDATE " . $this->_table . " SET rght=rght+2 WHERE rght>=" . $next_right;
          $this->_db->Execute($sql) or die("Error: " . $this->_db->ErrorMsg());
          $sql = "UPDATE " . $this->_table . " SET lft=lft+2 WHERE lft>=" . $next_right;
          $this->_db->Execute($sql) or die("Error: " . $this->_db->ErrorMsg());
          
          $id = $this->_db->GenID($this->_table . "_seq");
          $sql = "INSERT INTO " . $this->_table . " SET name='" . $name . "', value='" . $value . "', lft='" . $next_right . "', rght='" . ($next_right + 1) . "', parent='" . $parent_id . "', id='" . $id . "'";
          $this->_db->Execute($sql) or die("Error: $sql :: " . $this->_db->ErrorMsg());
          //$this->rebuild_tree(1,1);
          $this->load_tree();
          return $id;
        }
        
        /*
        *       Call this to delete a node from the tree, the nodes children (and their children, etc) will become children
        *       of the deleted nodes parent
        *       @param int $id id of the node you want to delete
        */
        function delete_node($id) {
          
          $sql = "SELECT * from " . $this->_table . " where id = '" . $id . "'";
          //echo $sql . "<br>";
          $result = $this->_db->Execute($sql) or die("Error: " . $this->_db->ErrorMsg());
   
          $left = 0;
          $right = 1;
          $new_parent = 0;
          
          if ($result && !$result->EOF) {
            $left = $result->fields['lft'];
            $right = $result->fields['rght'];
            $new_parent = $result->fields['parent'];
          }
   
          $sql = "UPDATE " . $this->_table . " SET rght=rght-2 WHERE rght>" . $right;
          //echo $sql . "<br>";
          $this->_db->Execute($sql) or die("Error: " . $this->_db->ErrorMsg());
          
           $sql = "UPDATE " . $this->_table . " SET lft=lft-2 WHERE lft>" . $right;
          //echo $sql . "<br>";
          $this->_db->Execute($sql) or die("Error: " . $this->_db->ErrorMsg());
          
          $sql = "UPDATE " . $this->_table . " SET lft=lft-1, rght=rght-1 WHERE lft>" . $left . " and rght < " . $right;
          //echo $sql . "<br>";
          $this->_db->Execute($sql) or die("Error: " . $this->_db->ErrorMsg());
   
          //only update the childrens parent setting if the node has children
          if ($right > ($left +1)) {
            $sql = "UPDATE " . $this->_table . " SET parent='" . $new_parent . "' WHERE parent='" . $id . "'";
            //echo $sql . "<br>";       
            $this->_db->Execute($sql) or die("Error: " . $this->_db->ErrorMsg());
          }
          
          $sql = "DELETE FROM " . $this->_table . " where id='" . $id . "'";
          //echo $sql . "<br>";
          $this->_db->Execute($sql) or die("Error: " . $this->_db->ErrorMsg());
          $this->load_tree();
          
          return true;
        }
        
        function get_node_info($id) {
                if(!empty($this->_id_name[$id])) {
                        return $this->_id_name[$id];
                }
                else {
                        return array();
                }
        }
        
        function get_node_name($id) {
                if(!empty($this->_id_name[$id])) {
                        return $this->_id_name[$id]['name'];
                }
                else {
                        return false;
                }
        }

}

function array_merge_2(&$array, &$array_i) {
       // For each element of the array (key => value):
       foreach ($array_i as $k => $v) {
           // If the value itself is an array, the process repeats recursively:
           if (is_array($v)) {
               if (!isset($array[$k])) {
                   $array[$k] = array();
               }
               array_merge_2($array[$k], $v);

           // Else, the value is assigned to the current element of the resulting array:
           } else {
               if (isset($array[$k]) && is_array($array[$k])) {
                   $array[$k][0] = $v;
               } else {
                   if (isset($array) && !is_array($array)) {
                       $temp = $array;
                       $array = array();
                       $array[0] = $temp;
                   }
                   $array[$k] = $v;
               }
           }
       }
   }


   function array_merge_n() {
       // Initialization of the resulting array:
       $array = array();

       // Arrays to be merged (function's arguments):
       $arrays =& func_get_args();

       // Merging of each array with the resulting one:
       foreach ($arrays as $array_i) {
           if (is_array($array_i)) {
               array_merge_2($array, $array_i);
           }
       }

       return $array;
   }


/*
$db = $GLOBALS['adodb']['db'];
$sql = "USE document;";
$db->Execute($sql);
$t = new Tree(1);
echo "<pre>";
print_r($t->tree);
//$nid = $t->add_node(0,"test node2","test value");
//$t->add_node($nid,"test child","another value");
//$t->add_node($nid,"test child");
print_r($t->tree);
echo "</pre>";
*/
?>