class views_handler

class views_handler extends views_object {
    
    /**
     * The top object of a view.
     *
     * @var view
     */
    public $view = NULL;
    
    /**
     * Where the $query object will reside:.
     *
     * @var views_plugin_query
     */
    public $query = NULL;
    
    /**
     * The type of the handler, for example filter/footer/field.
     */
    public $handler_type = NULL;
    
    /**
     * The alias of the table of this handler which is used in the query.
     */
    public $table_alias;
    
    /**
     * The actual field in the database table, maybe different
     * on other kind of query plugins/special handlers.
     */
    public $real_field;
    
    /**
     * The relationship used for this field.
     */
    public $relationship = NULL;
    
    /**
     * Init the handler with necessary data.
     *
     * @param view $view
     *   The $view object this handler is attached to.
     * @param array $options
     *   The item from the database; the actual contents of this will vary
     *   based upon the type of handler.
     */
    public function init(&$view, &$options) {
        $this->view =& $view;
        $display_id = $this->view->current_display;
        // Check to see if this handler type is defaulted. Note that
        // we have to do a lookup because the type is singular but the
        // option is stored as the plural.
        // If the 'moved to' keyword moved our handler, let's fix that now.
        if (isset($this->actual_table)) {
            $options['table'] = $this->actual_table;
        }
        if (isset($this->actual_field)) {
            $options['field'] = $this->actual_field;
        }
        $types = views_object_types();
        $plural = $this->handler_type;
        if (isset($types[$this->handler_type]['plural'])) {
            $plural = $types[$this->handler_type]['plural'];
        }
        if ($this->view->display_handler
            ->is_defaulted($plural)) {
            $display_id = 'default';
        }
        $this->localization_keys = array(
            $display_id,
            $this->handler_type,
            $options['table'],
            $options['id'],
        );
        $this->unpack_options($this->options, $options);
        // This exist on most handlers, but not all. So they are still optional.
        if (isset($options['table'])) {
            $this->table = $options['table'];
        }
        if (isset($this->definition['real field'])) {
            $this->real_field = $this->definition['real field'];
        }
        if (isset($this->definition['field'])) {
            $this->real_field = $this->definition['field'];
        }
        if (isset($options['field'])) {
            $this->field = $options['field'];
            if (!isset($this->real_field)) {
                $this->real_field = $options['field'];
            }
        }
        $this->query =& $view->query;
    }
    
    /**
     * {@inheritdoc}
     */
    public function option_definition() {
        $options = parent::option_definition();
        $options['id'] = array(
            'default' => '',
        );
        $options['table'] = array(
            'default' => '',
        );
        $options['field'] = array(
            'default' => '',
        );
        $options['relationship'] = array(
            'default' => 'none',
        );
        $options['group_type'] = array(
            'default' => 'group',
        );
        $options['ui_name'] = array(
            'default' => '',
        );
        return $options;
    }
    
    /**
     * Return a string representing this handler's name in the UI.
     */
    public function ui_name($short = FALSE) {
        if (!empty($this->options['ui_name'])) {
            $title = check_plain($this->options['ui_name']);
            return $title;
        }
        $title = $short && isset($this->definition['title short']) ? $this->definition['title short'] : $this->definition['title'];
        if (empty($this->definition['group'])) {
            return $title;
        }
        return t('!group: !title', array(
            '!group' => $this->definition['group'],
            '!title' => $title,
        ));
    }
    
    /**
     * Shortcut to get a handler's raw field value.
     *
     * This should be overridden for handlers with formulae or other
     * non-standard fields. Because this takes an argument, fields
     * overriding this can just call return parent::get_field($formula)
     */
    public function get_field($field = NULL) {
        if (!isset($field)) {
            if (!empty($this->formula)) {
                $field = $this->get_formula();
            }
            else {
                $field = $this->table_alias . '.' . $this->real_field;
            }
        }
        // If grouping, check to see if the aggregation method needs to modify the
        // field.
        if ($this->view->display_handler
            ->use_group_by()) {
            $this->view
                ->init_query();
            if ($this->query) {
                $info = $this->query
                    ->get_aggregation_info();
                if (!empty($info[$this->options['group_type']]['method']) && function_exists($info[$this->options['group_type']]['method'])) {
                    return $info[$this->options['group_type']]['method']($this->options['group_type'], $field);
                }
            }
        }
        return $field;
    }
    
    /**
     * Sanitize the value for output.
     *
     * @param string $value
     *   The value being rendered.
     * @param string $type
     *   The type of sanitization needed. If not provided, check_plain() is used.
     *
     * @return string
     *   Returns the safe value.
     */
    public function sanitize_value($value, $type = NULL) {
        if (!is_null($value) && strlen($value) > 0) {
            switch ($type) {
                case 'xss':
                    $value = filter_xss($value);
                    break;
                case 'xss_admin':
                    $value = filter_xss_admin($value);
                    break;
                case 'url':
                    $value = check_url($value);
                    break;
                default:
                    $value = check_plain($value);
                    break;
            }
        }
        return $value;
    }
    
    /**
     * Transform a string by a certain method.
     *
     * @param string $string
     *   The input you want to transform.
     * @param array $option
     *   How do you want to transform it, possible values:
     *      - upper: Uppercase the string.
     *      - lower: lowercase the string.
     *      - ucfirst: Make the first char uppercase.
     *      - ucwords: Make each word in the string uppercase.
     *
     * @return string
     *   The transformed string.
     */
    public function case_transform($string, $option) {
        global $multibyte;
        switch ($option) {
            default:
                return $string;
            case 'upper':
                return drupal_strtoupper($string);
            case 'lower':
                return drupal_strtolower($string);
            case 'ucfirst':
                return drupal_strtoupper(drupal_substr($string, 0, 1)) . drupal_substr($string, 1);
            case 'ucwords':
                if ($multibyte == UNICODE_MULTIBYTE) {
                    return mb_convert_case($string, MB_CASE_TITLE);
                }
                else {
                    return ucwords($string);
                }
        }
    }
    
    /**
     * Validate the options form.
     */
    public function options_validate(&$form, &$form_state) {
    }
    
    /**
     * Build the options form.
     */
    public function options_form(&$form, &$form_state) {
        // Some form elements belong in a fieldset for presentation, but can't
        // be moved into one because of the form_state['values'] hierarchy. Those
        // elements can add a #fieldset => 'fieldset_name' property, and they'll
        // be moved to their fieldset during pre_render.
        $form['#pre_render'][] = 'views_ui_pre_render_add_fieldset_markup';
        $form['ui_name'] = array(
            '#type' => 'textfield',
            '#title' => t('Administrative title'),
            '#description' => t('This title will be displayed on the views edit page instead of the default one. This might be useful if you have the same item twice.'),
            '#default_value' => $this->options['ui_name'],
            '#fieldset' => 'more',
        );
        // This form is long and messy enough that the "Administrative title" option
        // belongs in a "more options" fieldset at the bottom of the form.
        $form['more'] = array(
            '#type' => 'fieldset',
            '#title' => t('More'),
            '#collapsible' => TRUE,
            '#collapsed' => TRUE,
            '#weight' => 150,
        );
        // Allow to alter the default values brought into the form.
        // Triggers hook_views_handler_options_alter().
        drupal_alter('views_handler_options', $this->options, $this);
    }
    
    /**
     * Perform any necessary changes to the form values prior to storage.
     * There is no need for this function to actually store the data.
     */
    public function options_submit(&$form, &$form_state) {
    }
    
    /**
     * Provides the handler some groupby.
     */
    public function use_group_by() {
        return TRUE;
    }
    
    /**
     * Provide a form for aggregation settings.
     */
    public function groupby_form(&$form, &$form_state) {
        $view =& $form_state['view'];
        $display_id = $form_state['display_id'];
        $types = views_object_types();
        $type = $form_state['type'];
        $id = $form_state['id'];
        $form['#title'] = check_plain($view->display[$display_id]->display_title) . ': ';
        $form['#title'] .= t('Configure aggregation settings for @type %item', array(
            '@type' => $types[$type]['lstitle'],
            '%item' => $this->ui_name(),
        ));
        $form['#section'] = $display_id . '-' . $type . '-' . $id;
        $view->init_query();
        $info = $view->query
            ->get_aggregation_info();
        foreach ($info as $id => $aggregate) {
            $group_types[$id] = $aggregate['title'];
        }
        $form['group_type'] = array(
            '#type' => 'select',
            '#title' => t('Aggregation type'),
            '#default_value' => $this->options['group_type'],
            '#description' => t('Select the aggregation function to use on this field.'),
            '#options' => $group_types,
        );
    }
    
    /**
     * Perform any necessary changes to the form values prior to storage.
     * There is no need for this function to actually store the data.
     */
    public function groupby_form_submit(&$form, &$form_state) {
        $item =& $form_state['handler']->options;
        $item['group_type'] = $form_state['values']['options']['group_type'];
    }
    
    /**
     * If a handler has 'extra options' it will get a little settings widget and
     * another form called extra_options.
     */
    public function has_extra_options() {
        return FALSE;
    }
    
    /**
     * Provide defaults for the handler.
     */
    public function extra_options(&$option) {
    }
    
    /**
     * Provide a form for setting options.
     */
    public function extra_options_form(&$form, &$form_state) {
    }
    
    /**
     * Validate the options form.
     */
    public function extra_options_validate($form, &$form_state) {
    }
    
    /**
     * Perform any necessary changes to the form values prior to storage.
     * There is no need for this function to actually store the data.
     */
    public function extra_options_submit($form, &$form_state) {
    }
    
    /**
     * Determine if a handler can be exposed.
     */
    public function can_expose() {
        return FALSE;
    }
    
    /**
     * Set new exposed option defaults when exposed setting is flipped
     * on.
     */
    public function expose_options() {
    }
    
    /**
     * Get information about the exposed form for the form renderer.
     */
    public function exposed_info() {
    }
    
    /**
     * Render our chunk of the exposed handler form when selecting.
     */
    public function exposed_form(&$form, &$form_state) {
    }
    
    /**
     * Validate the exposed handler form.
     */
    public function exposed_validate(&$form, &$form_state) {
    }
    
    /**
     * Submit the exposed handler form.
     */
    public function exposed_submit(&$form, &$form_state) {
    }
    
    /**
     * Form for exposed handler options.
     */
    public function expose_form(&$form, &$form_state) {
    }
    
    /**
     * Validate the options form.
     */
    public function expose_validate($form, &$form_state) {
    }
    
    /**
     * Perform any necessary changes to the form exposes prior to storage.
     * There is no need for this function to actually store the data.
     */
    public function expose_submit($form, &$form_state) {
    }
    
    /**
     * Shortcut to display the expose/hide button.
     */
    public function show_expose_button(&$form, &$form_state) {
    }
    
    /**
     * Shortcut to display the exposed options form.
     */
    public function show_expose_form(&$form, &$form_state) {
        if (empty($this->options['exposed'])) {
            return;
        }
        $this->expose_form($form, $form_state);
        // When we click the expose button, we add new gadgets to the form but they
        // have no data in $_POST so their defaults get wiped out. This prevents
        // these defaults from getting wiped out. This setting will only be TRUE
        // during a 2nd pass rerender.
        if (!empty($form_state['force_expose_options'])) {
            foreach (element_children($form['expose']) as $id) {
                if (isset($form['expose'][$id]['#default_value']) && !isset($form['expose'][$id]['#value'])) {
                    $form['expose'][$id]['#value'] = $form['expose'][$id]['#default_value'];
                }
            }
        }
    }
    
    /**
     * Check whether current user has access to this handler.
     *
     * @return bool
     */
    public function access() {
        if (isset($this->definition['access callback']) && function_exists($this->definition['access callback'])) {
            if (isset($this->definition['access arguments']) && is_array($this->definition['access arguments'])) {
                return call_user_func_array($this->definition['access callback'], $this->definition['access arguments']);
            }
            return $this->definition['access callback']();
        }
        return TRUE;
    }
    
    /**
     * Run before the view is built.
     *
     * This gives all the handlers some time to set up before any handler has
     * been fully run.
     */
    public function pre_query() {
    }
    
    /**
     * Run after the view is executed, before the result is cached.
     *
     * This gives all the handlers some time to modify values. This is primarily
     * used so that handlers that pull up secondary data can put it in the
     * $values so that the raw data can be utilized externally.
     */
    public function post_execute(&$values) {
    }
    
    /**
     * Provides a unique placeholders for handlers.
     */
    public function placeholder() {
        return $this->query
            ->placeholder($this->options['table'] . '_' . $this->options['field']);
    }
    
    /**
     * Called just prior to query(), this lets a handler set up any relationship
     * it needs.
     */
    public function set_relationship() {
        // Ensure this gets set to something.
        $this->relationship = NULL;
        // Don't process non-existant relationships.
        if (empty($this->options['relationship']) || $this->options['relationship'] == 'none') {
            return;
        }
        $relationship = $this->options['relationship'];
        // Ignore missing/broken relationships.
        if (empty($this->view->relationship[$relationship])) {
            return;
        }
        // Check to see if the relationship has already processed. If not, then we
        // cannot process it.
        if (empty($this->view->relationship[$relationship]->alias)) {
            return;
        }
        // Finally!
        $this->relationship = $this->view->relationship[$relationship]->alias;
    }
    
    /**
     * Ensure the main table for this handler is in the query. This is used
     * a lot.
     */
    public function ensure_my_table() {
        if (!isset($this->table_alias)) {
            if (!method_exists($this->query, 'ensure_table')) {
                vpr(t('Ensure my table called but query has no ensure_table method.'));
                return;
            }
            $this->table_alias = $this->query
                ->ensure_table($this->table, $this->relationship);
        }
        return $this->table_alias;
    }
    
    /**
     * Provide text for the administrative summary.
     */
    public function admin_summary() {
    }
    
    /**
     * Determine if the argument needs a style plugin.
     *
     * @return bool
     */
    public function needs_style_plugin() {
        return FALSE;
    }
    
    /**
     * Determine if this item is 'exposed', meaning it provides form elements
     * to let users modify the view.
     *
     * @return bool
     */
    public function is_exposed() {
        return !empty($this->options['exposed']);
    }
    
    /**
     * Returns TRUE if the exposed filter works like a grouped filter.
     */
    public function is_a_group() {
        return FALSE;
    }
    
    /**
     * Define if the exposed input has to be submitted multiple times.
     * This is TRUE when exposed filters grouped are using checkboxes as
     * widgets.
     */
    public function multiple_exposed_input() {
        return FALSE;
    }
    
    /**
     * Take input from exposed handlers and assign to this handler, if necessary.
     */
    public function accept_exposed_input($input) {
        return TRUE;
    }
    
    /**
     * If set to remember exposed input in the session, store it there.
     */
    public function store_exposed_input($input, $status) {
        return TRUE;
    }
    
    /**
     * Get the join object that should be used for this handler.
     *
     * This method isn't used a great deal, but it's very handy for easily
     * getting the join if it is necessary to make some changes to it, such
     * as adding an 'extra'.
     */
    public function get_join() {
        // Get the join from this table that links back to the base table.
        // Determine the primary table to seek.
        if (empty($this->query->relationships[$this->relationship])) {
            $base_table = $this->query->base_table;
        }
        else {
            $base_table = $this->query->relationships[$this->relationship]['base'];
        }
        $join = views_get_table_join($this->table, $base_table);
        if ($join) {
            return clone $join;
        }
    }
    
    /**
     * Validates the handler against the complete View.
     *
     * This is called when the complete View is being validated. For validating
     * the handler options form use options_validate().
     *
     * @see views_handler::options_validate()
     *
     * @return array
     *   Empty array if the handler is valid; an array of error strings if it is
     *   not.
     */
    public function validate() {
        return array();
    }
    
    /**
     * Determine if the handler is considered 'broken'.
     *
     * Generally only returns TRUE if the handler can't be found.
     *
     * @return bool
     *   The handler could not be loaded.
     */
    public function broken() {
    }

}