/tanora.org/www/framework/system/activerecord.php

<?php
/**
 * This is the base class for all active record models.
 */
 
require_once(FRAMEWORK_PATH.'system/model.php');

abstract class ActiveRecord extends Model implements Iterator, Countable{
	
	protected $db;
	protected $fields;
	protected $table;
	protected $query;
	
	/**
	 * Sets the ORM structure.
	 */
	public function __construct($db = 'default') {
		$this->db = Framework::load_database($db);
		$this->__structure();
		if($this->db instanceof SqlDatabase) {
			$this->query = $this->db->query('select');
			$this->query->from()->table($this->get_table());
		} else {
			// NoSQL database
		}
	}
	
	/**
	 * Must be defined in subclasses. Define the model structure here
	 * using the field() method.
	 */
	abstract protected function __structure();
	
	/**
	 * Loads Field object into the fields member variable and returns
	 * the reference.
	 */
	protected function _field($name) {
		require_once(FRAMEWORK_PATH.'system/field.php');
		$dirs = array(FIELD_PATH, FRAMEWORK_PATH.'fields/');
		foreach($dirs as $dir) {
			$file = $dir.strtolower($name).'field.php';
			if(file_exists($file)) {
				require_once($file);
				$index = count($this->fields);
				$class = $name.'Field';
				$this->fields[$index] = new $class($this->db);
				return $this->fields[$index];
			}
		}
		Framework::error('Cannot load field: '.$name);
	}
	
	/**
	 * Sets the table member variable.
	 */
	protected function _table($name) {
		$this->table = $name;
	}
	
	/**
	 * Gets the table member variable.
	 */
	public function get_table() {
		return $this->table;
	}
    
	/**
	 * Returns the list of fields as a reference.
	 */
	public function get_fields() {
		return $this->fields;
	}
	
	/**
	 * Returns a reference to a single field.
	 */
	public function get_field($name) {
		foreach($this->get_fields() as $field) {
			if($field->get_name() == $name) {
				return $field;
			}
		}
		Framework::error('Field '.$name.' does not exist in '.get_class($this));
	}
	
	/**
	 * Returns a Form object with the appropriate ORM reference.
	 */
	public function form() {
		require_once(FRAMEWORK_PATH.'system/form.php');
		return new Form($this);
	}
	
	/**
	 * Sets the query member variable and returns the reference.
	 */
	public function query() {
		return $this->query;
	}
	
	/**
	 * Loads the row at the specified index.
	 */
	public function load($index) {
		$row = $this->query->get($index);
		$this->set($row);
	}
	
	/**
	 * Counts the number of rows, from Countable interface.
	 */
	public function count() {
		return count($this->query);
	}
	
	/**
	 * Gets the current row.
	 */
	public function current() {
		$row = $this->query->current();
		$this->set($row);
		return $this;
	}
	
	/**
	 * Rewinds.
	 */
	public function rewind() {
		$this->query->rewind();
	}
	
	/**
	 * Returns the position.
	 */
	public function key() {
		return $this->query->key();
	}
	
	/**
	 * Moves to the next row.
	 */
	public function next() {
		$this->query->next();
	}
	
	/**
	 * Checks if row exists.
	 */
	public function valid() {
		return $this->query->valid();
	}
	
	/**
	 * Gets the query result.
	 */
	public function fill() {
		$result = $this->query->result();
		// loads the first result automatically
		if(count($this->query) > 0) {
			$this->load(0);
		}
	}
	
	/**
	 * Sets the Field values with values from an object.
	 */
	public function set($obj) {
		foreach($this->get_fields() as $field) {
			$name = $field->get_name();
			if(isset($obj->$name)) {
				$field->set_value($obj->$name);
			}
		}
	}
	
	/**
	 * Inserts the field values in the database (or overwrites existing
	 * ones).
	 */
	public function save() {
		if($this->db instanceof SqlDatabase) {
			$query = $this->db->query('replace');
			$query->table($this->get_table());
			foreach($this->get_fields() as $field) {
				$value = $field->get_column()->get_value();
				$query->set($field->get_name(), $value);
			}
			$query->run();
		} else {
			// NoSQL database
		}
	}
	
	/**
	 * Deletes the value from the database.
	 */
	public function delete() {
		if($this->db instanceof SqlDatabase) {
			$query = $this->db->query('delete');
			$pkey = $this->db->primary_key($this->get_table());
			$query->from($this->get_table());
			$query->where()->condition($pkey, $this->$pkey);
			$query->run();
		} else {
			// NoSQL database
		}
	}
	
	/**
	 * Creates the database table.
	 */
	public function sync() {
		if($this->db instanceof SqlDatabase) {
			// TODO: don't drop the table
			$query = $this->db->query('drop');
			$query->table($this->get_table());
			$query->if_exists();
			$query->run();
			
			$query = $this->db->query('create');
			$query->name($this->get_table());
			foreach($this->get_fields() as $field) {
				$column = $field->get_column();
				$column->create($query);
			}
			$query->run();
		} else {
			// NoSQL database
		}
	}
	
	/**
	 * Returns the value of a field.
	 */
	public function __get($field) {
		if(isset($this->$field)) {
			$field = $this->get_field($field);
			return $field->get_value();
		}
	}
	
	/**
	 * Checks if a field exists.
	 */
	public function __isset($field) {
		if(!is_null($this->get_field($field))) {
			return !is_null($this->get_field($field)->get_value());
		}
		return FALSE;
	}
	
	/**
	 * Sets the value of a field.
	 */
	public function __set($field, $value) {
		if(!is_null($this->get_field($field))) {
			$this->get_field($field)->set_value($value);
		}
	}
	
}

?>