nested_set

Tiny class which provides basic functions for manipulating with "Nested Set" database tree.

Preparing

Create the database table

DROP TABLE IF EXISTS ns_tree;
CREATE TABLE ns_tree (
    id INT AUTO_INCREMENT PRIMARY KEY,
    lft INT NOT NULL,
    rgt INT NOT NULL,
    -- you can add whatever you want with text type
    -- such as 'name','description','link' etc
    name VARCHAR(255),
    link VARCHAR(255)
);
INSERT INTO ns_tree (lft,rgt,name,link) VALUES(1,2,'root','root_link');

Setup PDO-connection. The class sets PDO attribute PDO::ATTR_ERRMODE equal to PDO::ERRMODE_EXCEPTION if it isn't set yet

...
$pdo = new \PDO(DB_CONN_STRING, DB_USER, DB_PASS,
    array(PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION)
);

Configuring

$aConfig = array(
    'tb_name' => 'ns_tree',
    'tb_field_index'=> 'id',
    'tb_field_left' => 'lft',
    'tb_field_right' => 'rgt',
    'tb_extra_fields'=> array(
        'name',
        'link'
    )
);

Usage

create the object

$ns = new CNestedSet($pdo, $aConfig);

add new node

Pass array with extra fields' values

$aNewNode = array(
    'name' => 'new node name',
    'link' => 'new node link'
);
$nd1 = $ns->addChild(1, $aNewNode); 

print the tree

Returns array with 'depth' values.

print_r($ns->getTree($nd1), TRUE);

Look at the examples folder for more information.

Available methods

• getTree($parent_id) - return all descendants of $parent_id node
• addChild($parent_id, $values) - add a new node to $parent_id which contains $values
• addRootChild($values) - add new node to the root element
• moveTree($cur_parent_id, $new_parent_id) - move the whole tree to a new parent
• deleteTree($node_id) - delete $node_id with all descendants
• deleteNode($node_id) - delete $node_id only and shift the descendants to level up

Requirements

• database has to transactions support
• database has to locks support