Bagaimana Bekerja dengan hierarchical data trees di CodeIgniter 2 ?

Update : Pustaka yang dibuat oleh thunder[1] dan update pustaka thunder yang mendukung multiple root [2] sudah tidak kompatibel lagi dengan CI2, jika ingin menggunakan Nested Set di CI2 sebaiknya menggunakan ORM Datamapper [2]

===Kadaluarsa===

Untuk bekerja dengan hierarchical data trees di CodeIgniter 2 (tanpa menggunakan ORM pihak ketiga seperti Doctrine), maka dapat menggunakan library yang sudah dibuat oleh thunder [1].

Berikut adalah snippet kode untuk mengambil data 1 level dibawah parent pada sebuah struktur nested set (Kode lengkap dapat dilihat di : https://bitbucket.org/wildanm/e-office/src/a4d01d801a81/application/modules/kepegawaian/models/unit_organisasi_model.php) :

/** * @TODO - Buat agar query nya tidak depend ke unit_organisasi saja * Dan dipindah ke nested_sets_model * - Algoritma lebih dioptimasi * @see http://stackoverflow.com/questions/7582292/nested-set-model-query-node-childs-only-1-level-below-and-all-parents-above */ function getTreeWithDepth($node,$depth) { $table = $this->table_name; $leftcol = $this->left_column_name; $rightcol = $this->right_column_name; $leftval = (int) $node[$leftcol]; $rightval = (int) $node[$rightcol]; $sql = "SELECT node.kode_unit, node.nama, (COUNT(parent.kode_unit) - (sub_tree.depth + 1)) AS depth FROM $table AS node, $table AS parent, $table AS sub_parent, ( SELECT node.kode_unit, node.nama, (COUNT(parent.kode_unit) - 1) AS depth FROM $table AS node, $table AS parent WHERE node.$leftcol BETWEEN parent.$leftcol AND parent.$rightcol AND node.kode_unit = '{$node['kode_unit']}' GROUP BY node.kode_unit, node.nama,node.$leftcol ORDER BY node.$leftcol )AS sub_tree WHERE node.$leftcol BETWEEN parent.$leftcol AND parent.$rightcol AND node.$leftcol BETWEEN sub_parent.$leftcol AND sub_parent.$rightcol AND sub_parent.nama = sub_tree.nama AND node.kode_unit != '{$node['kode_unit']}' GROUP BY node.kode_unit, node.nama, sub_tree.depth, node.$leftcol ORDER BY node.$leftcol;"; $query = $this->db->query($sql); $treeArray = array(); if($query->num_rows() > 0) { foreach($query->result_array() AS $result) { $current_node = $this->getNodeFromId($result["kode_unit"]) ; $parent_node = $this->getAncestor($current_node); if($result["depth"] == $depth) { if($parent_node["kode_unit"] == $node["kode_unit"]) { $treeArray[] = $result; } } } } $retArray = array( "result_array" => $treeArray, "prev_left" => $node[$leftcol], "prev_right" => $node[$rightcol], "level" => -2); return $retArray; }

===END Kadaluarsa===

Referensi

• 1. Nested sets, http://codeigniter.com/wiki/Nested_sets

  2. Nested sets with multiple root support, http://codeigniter.com/forums/viewthread/92540/

  3. Nested sets operation using Datamapper ORM, http://datamapper.wanwizard.eu/pages/extensions/nestedsets.html