<?php
/**
* @package Joomla.Platform
* @subpackage Application
*
* @copyright Copyright (C) 2005 - 2011 Open Source Matters, Inc. All rights reserved.
* @license GNU General Public License version 2 or later; see LICENSE
*/
defined('JPATH_PLATFORM') or die;
jimport('joomla.application.component.model');
/**
* Model class for handling lists of items.
*
* @package Joomla.Platform
* @subpackage Application
* @since 11.1
*/
class JModelList extends JModel
{
/**
* Internal memory based cache array of data.
*
* @var array
* @since 11.1
*/
protected $cache = array();
/**
* Context string for the model type. This is used to handle uniqueness
* when dealing with the getStoreId() method and caching data structures.
*
* @var string
* @since 11.1
*/
protected $context = null;
/**
* Valid filter fields or ordering.
*
* @var array
* @since 11.1
*/
protected $filter_fields = array();
/**
* An internal cache for the last query used.
*
* @var JDatabaseQuery
* @since 11.1
*/
protected $query = array();
/**
* Constructor.
*
* @param array An optional associative array of configuration settings.
* @see JController
*/
public function __construct($config = array())
{
parent::__construct($config);
// Add the ordering filtering fields white list.
if (isset($config['filter_fields'])) {
$this->filter_fields = $config['filter_fields'];
}
// Guess the context as Option.ModelName.
if (empty($this->context)) {
$this->context = strtolower($this->option.'.'.$this->getName());
}
}
/**
* Method to cache the last query constructed.
*
* This method ensures that the query is contructed only once for a given state of the model.
*
* @return JDatabaseQuery
* @since 11.1
*/
private function _getListQuery()
{
// Capture the last store id used.
static $lastStoreId;
// Compute the current store id.
$currentStoreId = $this->getStoreId();
// If the last store id is different from the current, refresh the query.
if ($lastStoreId != $currentStoreId || empty($this->query)) {
$lastStoreId = $currentStoreId;
$this->query = $this->getListQuery();
}
return $this->query;
}
/**
* Method to get an array of data items.
*
* @return mixed An array of data items on success, false on failure.
* @since 11.1
*/
public function getItems()
{
// Get a storage key.
$store = $this->getStoreId();
// Try to load the data from internal storage.
if (!empty($this->cache[$store])) {
return $this->cache[$store];
}
// Load the list items.
$query = $this->_getListQuery();
$items = $this->_getList($query, $this->getStart(), $this->getState('list.limit'));
// Check for a database error.
if ($this->_db->getErrorNum()) {
$this->setError($this->_db->getErrorMsg());
return false;
}
// Add the items to the internal cache.
$this->cache[$store] = $items;
return $this->cache[$store];
}
/**
* Method to get a JDatabaseQuery object for retrieving the data set from a database.
*
* @return object A JDatabaseQuery object to retrieve the data set.
* @since 11.1
*/
protected function getListQuery()
{
$db = $this->getDbo();
$query = $db->getQuery(true);
return $query;
}
/**
* Method to get a JPagination object for the data set.
*
* @return object A JPagination object for the data set.
* @since 11.1
*/
public function getPagination()
{
// Get a storage key.
$store = $this->getStoreId('getPagination');
// Try to load the data from internal storage.
if (!empty($this->cache[$store])) {
return $this->cache[$store];
}
// Create the pagination object.
jimport('joomla.html.pagination');
$limit = (int) $this->getState('list.limit') - (int) $this->getState('list.links');
$page = new JPagination($this->getTotal(), $this->getStart(), $limit);
// Add the object to the internal cache.
$this->cache[$store] = $page;
return $this->cache[$store];
}
/**
* Method to get a store id based on the model configuration state.
*
* This is necessary because the model is used by the component and
* different modules that might need different sets of data or different
* ordering requirements.
*
* @param string An identifier string to generate the store id.
* @return string A store id.
* @since 11.1
*/
protected function getStoreId($id = '')
{
// Add the list state to the store id.
$id .= ':'.$this->getState('list.start');
$id .= ':'.$this->getState('list.limit');
$id .= ':'.$this->getState('list.ordering');
$id .= ':'.$this->getState('list.direction');
return md5($this->context.':'.$id);
}
/**
* Method to get the total number of items for the data set.
*
* @return integer The total number of items available in the data set.
* @since 11.1
*/
public function getTotal()
{
// Get a storage key.
$store = $this->getStoreId('getTotal');
// Try to load the data from internal storage.
if (!empty($this->cache[$store])) {
return $this->cache[$store];
}
// Load the total.
$query = $this->_getListQuery();
$total = (int) $this->_getListCount((string) $query);
// Check for a database error.
if ($this->_db->getErrorNum()) {
$this->setError($this->_db->getErrorMsg());
return false;
}
// Add the total to the internal cache.
$this->cache[$store] = $total;
return $this->cache[$store];
}
/**
* Method to get the starting number of items for the data set.
*
* @return integer The starting number of items available in the data set.
* @since 11.1
*/
public function getstart()
{
$store = $this->getStoreId('getstart');
// Try to load the data from internal storage.
if (!empty($this->cache[$store])) {
return $this->cache[$store];
}
$start = $this->getState('list.start');
$limit = $this->getState('list.limit');
$total = $this->getTotal();
if ($start > $total - $limit) {
$start = max(0, (int)(ceil($total / $limit) - 1) * $limit);
}
// Add the total to the internal cache.
$this->cache[$store] = $start;
return $this->cache[$store];
}
/**
* Method to auto-populate the model state.
*
* This method should only be called once per instantiation and is designed
* to be called on the first call to the getState() method unless the model
* configuration flag to ignore the request is set.
*
* Note. Calling getState in this method will result in recursion.
*
* @param string An optional ordering field.
* @param string An optional direction (asc|desc).
* @since 11.1
*/
protected function populateState($ordering = null, $direction = null)
{
// If the context is set, assume that stateful lists are used.
if ($this->context) {
$app = JFactory::getApplication();
$value = $app->getUserStateFromRequest('global.list.limit', 'limit', $app->getCfg('list_limit'));
$limit = $value;
$this->setState('list.limit', $limit);
$value = $app->getUserStateFromRequest($this->context.'.limitstart', 'limitstart', 0);
$limitstart = ($limit != 0 ? (floor($value / $limit) * $limit) : 0);
$this->setState('list.start', $limitstart);
// Check if the ordering field is in the white list, otherwise use the incoming value.
$value = $app->getUserStateFromRequest($this->context.'.ordercol', 'filter_order', $ordering);
if (!in_array($value, $this->filter_fields)) {
$value = $ordering;
$app->setUserState($this->context.'.ordercol', $value);
}
$this->setState('list.ordering', $value);
// Check if the ordering direction is valid, otherwise use the incoming value.
$value = $app->getUserStateFromRequest($this->context.'.orderdirn', 'filter_order_Dir', $direction);
if (!in_array(strtoupper($value), array('ASC', 'DESC', ''))) {
$value = $direction;
$app->setUserState($this->context.'.orderdirn', $value);
}
$this->setState('list.direction', $value);
}
else {
$this->setState('list.start', 0);
$this->state->set('list.limit', 0);
}
}
/**
* Gets the value of a user state variable and sets it in the session
* This is the same as the method in JApplication except that this also can optionally
* force you back to the first page when a filter has changed
*
* @param string The key of the user state variable.
* @param string The name of the variable passed in a request.
* @param string The default value for the variable if not found. Optional.
* @param string Filter for the variable, for valid values see {@link JFilterInput::clean()}. Optional.
* @param boolean If true, the limitstart in request is set to zero
* @return The request user state.
* @since 11.1
*/
public function getUserStateFromRequest($key, $request, $default = null, $type = 'none', $resetPage = true)
{
$app = JFactory::getApplication();
$old_state = $app->getUserState($key);
$cur_state = (!is_null($old_state)) ? $old_state : $default;
$new_state = JRequest::getVar($request, null, 'default', $type);
if (($cur_state != $new_state) && ($resetPage)){
JRequest::setVar('limitstart', 0);
}
// Save the new value only if it is set in this request.
if ($new_state !== null) {
$app->setUserState($key, $new_state);
}
else {
$new_state = $cur_state;
}
return $new_state;
}
}
