EDTSort.php

<?php

/**
 * EDTSort class file.
 *
 * @author Jan Was <janek.jan@gmail.com>
 *
 * @link http://www.yiiframework.com/
 *
 * @copyright Copyright &copy; 2011-2012 Jan Was
 * @license http://www.yiiframework.com/license/
 */

/**
 * EDTSort represents information relevant to sorting.
 * Changes:
 * - added property columns used instead of attributes.
 *
 * @see CSort
 */
class EDTSort extends CSort
{
    /**
     * @var bool whether the sorting can be applied to multiple attributes simultaneously.
     *           Defaults to false, which means each time the data can only be sorted by one attribute.
     */
    public $multiSort = true;

    /**
     * @var array
     */
    public $columns;
    /**
     * @var string the name of the GET parameter that specifies which attributes to be sorted
     *             in which direction. Defaults to 'sort'.
     */
    public $sortVar = 'iSortingCols';

    /**
     * @var string prefix for each GET parameter denoting index in property by which to sort
     */
    public $sortVarIdxPrefix = 'iSortCol_';

    /**
     * @var string prefix for each GET parameter denoting direction of sort for a column
     */
    public $sortVarDirPrefix = 'sSortDir_';

    private $_directions;

    /**
     * Constructor.
     *
     * @param string $modelClass the class name of data models that need to be sorted.
     *                           This should be a child class of {@link CActiveRecord}.
     * @param array  $columns
     */
    public function __construct($modelClass = null, $columns = null)
    {
        $this->modelClass = $modelClass;
        $this->columns = $columns;
    }

    /**
     * Returns the currently requested sort information.
     *
     * @return array sort directions indexed by attribute names.
     *               The sort direction is true if the corresponding attribute should be
     *               sorted in descending order.
     */
    public function getDirections()
    {
        if ($this->_directions === null) {
            $this->_directions = array();
            // treat columns as an indexed array, even if it's associative
            $columns = is_array($this->columns) ? array_values($this->columns) : $this->columns;
            if ($columns !== null && isset($_GET[$this->sortVar]) && ($iSortingCols = intval($_GET[$this->sortVar])) > 0) {
                for ($i = 0; $i < $iSortingCols && isset($_GET[$this->sortVarIdxPrefix.$i]) && isset($columns[intval($_GET[$this->sortVarIdxPrefix.$i])]); ++$i) {
                    $index = intval($_GET[$this->sortVarIdxPrefix.$i]);
                    $column = $columns[$index];
                    $attribute = null;
                    if (is_string($column) || isset($column['name'])) {
                        if (is_string($column)) {
                            $params = explode(':', $column);
                            if (isset($params[0])) {
                                $attribute = $params[0];
                            }
                        } else {
                            $attribute = $column['name'];
                        }
                    } else {
                        // checkbox or operations (buttons) column
                        //! @todo use FK for checkbox column? need to find it first
                    }
                    if ($attribute !== null && ($this->resolveAttribute($attribute)) !== false) {
                        $descending = isset($_GET[$this->sortVarDirPrefix.$i]) && $_GET[$this->sortVarDirPrefix.$i] == 'desc';
                        $this->_directions[$attribute] = $descending;
                        if (!$this->multiSort) {
                            return $this->_directions;
                        }
                    }
                }
            }
            if ($this->_directions === array() && is_array($this->defaultOrder)) {
                $this->_directions = $this->defaultOrder;
            }
        }

        return $this->_directions;
    }

    /**
     * Creates a URL that can lead to generating sorted data.
     *
     * @param CController $controller the controller that will be used to create the URL.
     * @param array       $directions the sort directions indexed by attribute names.
     *                                The sort direction can be either CSort::SORT_ASC for ascending order or
     *                                CSort::SORT_DESC for descending order.
     *
     * @return string the URL for sorting
     */
    public function createUrl($controller, $directions)
    {
        $params = $this->params === null ? $_GET : $this->params;

        $columns = is_array($this->columns) ? array_values($this->columns) : $this->columns;
        if (empty($columns)) {
            return $controller->createUrl($this->route);
        }
        $i = 0;
        foreach ($params as $key => $val) {
            if (strpos($key, $this->sortVarIdxPrefix) === false && strpos($key, $this->sortVarDirPrefix) === false) {
                continue;
            }

            unset($params[$key]);
        }
        unset($params[$this->sortVar]);

        foreach ($columns as $key => $column) {
            if (!is_string($column) && !isset($column['name'])) {
                continue;
            }

            $attribute = null;
            if (is_string($column)) {
                $columnConfig = explode(':', $column);
                if (!isset($columnConfig[0])) {
                    continue;
                }

                $attribute = $columnConfig[0];
            } else {
                $attribute = $column['name'];
            }

            if ($attribute === null || !isset($directions[$attribute])) {
                continue;
            }

            /* Check if we need to disable sorting for this column */
            $currentDirection = false;
            foreach ($_GET as $k => $v) {
                if (strpos($k, $this->sortVarIdxPrefix) === false || intval($v) !== $key) {
                    continue;
                }

                $index = intval(substr($k, strlen($this->sortVarIdxPrefix)));
                $currentDirection = isset($_GET[$this->sortVarDirPrefix.$index]) && $_GET[$this->sortVarDirPrefix.$index] == 'desc';
                break;
            }

            /** Do not sort at all by this column when current direction (in $_GET) is different than one set in $directions */
            if ($currentDirection && $currentDirection != $directions[$attribute]) {
                continue;
            }

            $params[$this->sortVarIdxPrefix.$i] = $key;
            if ($directions[$attribute]) {
                $params[$this->sortVarDirPrefix.$i] = 'desc';
            }
            $i++;

            if (!$this->multiSort) {
                break;
            }
        }

        $params[$this->sortVar] = $i;

        return $controller->createUrl($this->route, $params);
    }
}