I found this script below online, and I'm wondering how I can do the same thing with a Ruby on Rails setup.

So, first off, I ran this command: rails g model Node node_id:integer title:string

Given this set up, how can I make a tree from a tabbed string like the following?

<?php
// Make sure to have "Academia" be root node with nodeID of 1
$data = "
Social sciences
    Anthropology
        Biological anthropology
            Forensic anthropology
            Gene-culture coevolution
            Human behavioral ecology
            Human evolution
            Medical anthropology
            Paleoanthropology
            Population genetics
            Primatology
        Anthropological linguistics
            Synchronic linguistics (or Descriptive linguistics)
            Diachronic linguistics (or Historical linguistics)
            Ethnolinguistics
            Sociolinguistics
        Cultural anthropology
            Anthropology of religion
            Economic anthropology
            Ethnography
            Ethnohistory
            Ethnology
            Ethnomusicology
            Folklore
            Mythology
            Political anthropology
            Psychological anthropology
    Archaeology
        ...(goes on for a long time)
";

//echo "Checkpoint 2\n";

$lines = preg_split("/\n/", $data);

$parentids = array(0 => null);
$db = new PDO("host", 'username', 'pass');
$sql = 'INSERT INTO `TreeNode` SET ParentID = ?, Title = ?';
$stmt = $db->prepare($sql);


foreach ($lines as $line) {
    if (!preg_match('/^([\s]*)(.*)$/', $line, $m)) {
        continue;
    }
    $spaces = strlen($m[1]);
    //$level = intval($spaces / 4); //assumes four spaces per indent
    $level = strlen($m[1]); // if data is tab indented
    $title = $m[2];
    $parentid = ($level > 0 ? $parentids[$level - 1] : 1); //All "roots" are children of "Academia" which has an ID of "1";

    $rv = $stmt->execute(array($parentid, $title));

    $parentids[$level] = $db->lastInsertId();
    echo "inserted $parentid - " . $parentid . " title: " . $title . "\n";
}
?>