ViewDataTable.php

<?php
/**
 * Piwik - Open source web analytics
 *
 * @link http://piwik.org
 * @license http://www.gnu.org/licenses/gpl-3.0.html GPL v3 or later
 *
 * @category Piwik
 * @package Piwik
 */

/**
 * This class is used to load (from the API) and customize the output of a given DataTable.
 * The main() method will create an object implementing Piwik_View_Interface
 * You can customize the dataTable using the disable* methods.
 *
 * You can also customize the dataTable rendering using row metadata:
 * - 'html_label_prefix': If this metadata is present on a row, it's contents will be prepended
 *                        the label in the HTML output.
 * - 'html_label_suffix': If this metadata is present on a row, it's contents will be appended
 *                        after the label in the HTML output.
 *
 * Example:
 * In the Controller of the plugin VisitorInterest
 * <pre>
 *    function getNumberOfVisitsPerVisitDuration( $fetch = false)
 *  {
 *        $view = Piwik_ViewDataTable::factory( 'cloud' );
 *        $view->init( $this->pluginName,  __FUNCTION__, 'VisitorInterest.getNumberOfVisitsPerVisitDuration' );
 *        $view->setColumnsToDisplay( array('label','nb_visits') );
 *        $view->disableSort();
 *        $view->disableExcludeLowPopulation();
 *        $view->disableOffsetInformation();
 *
 *        return $this->renderView($view, $fetch);
 *    }
 * </pre>
 *
 * @see factory() for all the available output (cloud tags, html table, pie chart, vertical bar chart)
 * @package Piwik
 * @subpackage Piwik_ViewDataTable
 */
abstract class Piwik_ViewDataTable
{
    /**
     * Cache for getAllReportDisplayProperties result.
     * 
     * @var array
     */
    public static $reportPropertiesCache = null;

    /**
     * Flag used to make sure the main() is only executed once
     *
     * @var bool
     */
    protected $mainAlreadyExecuted = false;

    /**
     * Array of properties that are available in the view
     * Used to store UI properties, eg. "show_footer", "show_search", etc.
     *
     * @var array
     */
    protected $viewProperties = array();
    
    /**
     * If the current dataTable refers to a subDataTable (eg. keywordsBySearchEngineId for id=X) this variable is set to the Id
     *
     * @var bool|int
     */
    protected $idSubtable = false;

    /**
     * DataTable loaded from the API for this ViewDataTable.
     *
     * @var Piwik_DataTable
     */
    protected $dataTable = null;

    /**
     * List of filters to apply after the data has been loaded from the API
     *
     * @var array
     */
    protected $queuedFilters = array();

    /**
     * List of filter to apply just before the 'Generic' filters
     * These filters should delete rows from the table
     * @var array
     */
    protected $queuedFiltersPriority = array();

    /**
     * @see init()
     * @var string
     */
    protected $currentControllerAction;

    /**
     * @see init()
     * @var string
     */
    protected $currentControllerName;

    /**
     * This view should be an implementation of the Interface Piwik_View_Interface
     * The $view object should be created in the main() method.
     *
     * @var Piwik_View_Interface
     */
    protected $view = null;

    
    /**
     * Default constructor.
     */
    public function __construct()
    {
        $this->viewProperties['datatable_template'] = '@CoreHome/_dataTable';
        $this->viewProperties['show_goals'] = false;
        $this->viewProperties['show_ecommerce'] = false;
        $this->viewProperties['show_search'] = true;
        $this->viewProperties['show_table'] = true;
        $this->viewProperties['show_table_all_columns'] = true;
        $this->viewProperties['show_all_views_icons'] = true;
        $this->viewProperties['hide_all_views_icons'] = false;
        $this->viewProperties['hide_annotations_view'] = true;
        $this->viewProperties['show_bar_chart'] = true;
        $this->viewProperties['show_pie_chart'] = true;
        $this->viewProperties['show_tag_cloud'] = true;
        $this->viewProperties['show_export_as_image_icon'] = false;
        $this->viewProperties['show_export_as_rss_feed'] = true;
        $this->viewProperties['show_exclude_low_population'] = true;
        $this->viewProperties['show_offset_information'] = true;
        $this->viewProperties['show_pagination_control'] = true;
        $this->viewProperties['show_limit_control'] = false;
        $this->viewProperties['show_footer'] = true;
        $this->viewProperties['show_related_reports'] = true;
        $this->viewProperties['exportLimit'] = Piwik_Config::getInstance()->General['API_datatable_default_limit'];
        $this->viewProperties['highlight_summary_row'] = false;
        $this->viewProperties['metadata'] = array();
        $this->viewProperties['relatedReports'] = array();
        $this->viewProperties['title'] = 'unknown';
        $this->viewProperties['tooltip_metadata_name'] = false;
        $this->viewProperties['enable_sort'] = true;
        $this->viewProperties['disable_generic_filters'] = false;
        $this->viewProperties['disable_queued_filters'] = false;
        $this->viewProperties['keep_summary_row'] = false;
        $this->viewProperties['filter_excludelowpop'] = false;
        $this->viewProperties['filter_excludelowpop_value'] = false;
        $this->viewProperties['filter_pattern'] = false;
        $this->viewProperties['filter_column'] = false;
        $this->viewProperties['filter_limit'] = false;
        $this->viewProperties['filter_sort_column'] = false;
        $this->viewProperties['filter_sort_order'] = false;
        $this->viewProperties['custom_parameters'] = array();
        $this->viewProperties['translations'] = array_merge(
            Piwik_Metrics::getDefaultMetrics(),
            Piwik_Metrics::getDefaultProcessedMetrics()
        );
        $this->viewProperties['request_parameters_to_modify'] = array();
        $this->viewProperties['documentation'] = false;
        $this->viewProperties['subtable_controller_action'] = false;
        $this->viewProperties['datatable_css_class'] = $this->getDefaultDataTableCssClass();
        $this->viewProperties['columns_to_display'] = array();

        $columns = Piwik_Common::getRequestVar('columns', false);
        if ($columns !== false) {
            $this->viewProperties['columns_to_display'] = Piwik::getArrayFromApiParameter($columns);
            array_unshift($this->viewProperties['columns_to_display'], 'label');
        }
    }

    /**
     * Method to be implemented by the ViewDataTable_*.
     * This method should create and initialize a $this->view object @see Piwik_View_Interface
     *
     * @return mixed either prints the result or returns the output string
     */
    abstract public function main();

    /**
     * Unique string ID that defines the format of the dataTable, eg. "pieChart", "table", etc.
     *
     * @return string
     */
    abstract protected function getViewDataTableId();

    /**
     * Returns a Piwik_ViewDataTable_* object.
     * By default it will return a ViewDataTable_Html
     * If there is a viewDataTable parameter in the URL, a ViewDataTable of this 'viewDataTable' type will be returned.
     * If defaultType is specified and if there is no 'viewDataTable' in the URL, a ViewDataTable of this $defaultType will be returned.
     * If force is set to true, a ViewDataTable of the $defaultType will be returned in all cases.
     *
     * @param string $defaultType Any of these: table, cloud, graphPie, graphVerticalBar, graphEvolution, sparkline, generateDataChart*
     * @param string|bool $action
     * @return Piwik_ViewDataTable
     */
    static public function factory($defaultType = null, $action = false)
    {
        if ($action !== false) {
            $defaultProperties = self::getDefaultPropertiesForReport($action);
            if (isset($defaultProperties['default_view_type'])) {
                $defaultType = $defaultProperties['default_view_type'];
            }
        }
        
        if ($defaultType === null) {
            $defaultType = 'table';
        }

        $type = Piwik_Common::getRequestVar('viewDataTable', $defaultType, 'string');
        switch ($type) {
            case 'cloud':
                $result = new Piwik_ViewDataTable_Cloud();
                break;

            case 'graphPie':
                $result = new Piwik_ViewDataTable_GenerateGraphHTML_ChartPie();
                break;

            case 'graphVerticalBar':
                $result = new Piwik_ViewDataTable_GenerateGraphHTML_ChartVerticalBar();
                break;

            case 'graphEvolution':
                $result = new Piwik_ViewDataTable_GenerateGraphHTML_ChartEvolution();
                break;

            case 'sparkline':
                $result = new Piwik_ViewDataTable_Sparkline();
                break;

            case 'tableAllColumns':
                $result = new Piwik_ViewDataTable_HtmlTable_AllColumns();
                break;

            case 'tableGoals':
                $result = new Piwik_ViewDataTable_HtmlTable_Goals();
                break;

            case 'table':
            default:
                $result = new Piwik_ViewDataTable_HtmlTable();
                break;
        }
        
        if ($action !== false) {
            list($plugin, $controllerAction) = explode('.', $action);
            
            $subtableAction = $controllerAction;
            if (isset($defaultProperties['subtable_action'])) {
                $subtableAction = $defaultProperties['subtable_action'];
            }
            
            $result->init($plugin, $controllerAction, $action, $subtableAction, $defaultProperties);
        }
        
        return $result;
    }
    
    /**
     * Returns the list of view properties that can be overridden by query parameters.
     * 
     * @return array
     */
    public function getOverridableProperties()
    {
        return array(
            'show_search',
            'show_table',
            'show_table_all_columns',
            'show_all_views_icons',
            'hide_all_views_icons',
            'hide_annotations_view',
            'show_barchart',
            'show_piechart',
            'show_tag_cloud',
            'show_export_as_image_icon',
            'show_export_as_rss_feed',
            'show_exclude_low_population',
            'show_offset_information',
            'show_pagination_control',
            'show_footer',
            'show_related_reports',
            'columns'
        );
    }
    
    /**
     * Returns the list of view properties that should be sent with the HTML response
     * as JSON. These properties can be manipulated via the ViewDataTable UI.
     * 
     * @return array
     */
    public function getJavaScriptProperties()
    {
        return array(
            'enable_sort',
            'disable_generic_filters',
            'disable_queued_filters',
            'keep_summary_row',
            'filter_excludelowpop',
            'filter_excludelowpop_value',
            'filter_pattern',
            'filter_column',
            'filter_limit',
            'filter_sort_column',
            'filter_sort_order',
        );
    }

    /**
     * Inits the object given the $currentControllerName, $currentControllerAction of
     * the calling controller action, eg. 'Referers' 'getLongListOfKeywords'.
     * The initialization also requires the $apiMethodToRequestDataTable of the API method
     * to call in order to get the DataTable, eg. 'Referers.getKeywords'.
     * The optional $controllerActionCalledWhenRequestSubTable defines the method name of the API to call when there is a idSubtable.
     * This value would be used by the javascript code building the GET request to the API.
     *
     * Example:
     *    For the keywords listing, a click on the row loads the subTable of the Search Engines for this row.
     *  In this case $controllerActionCalledWhenRequestSubTable = 'getSearchEnginesFromKeywordId'.
     *  The GET request will hit 'Referers.getSearchEnginesFromKeywordId'.
     *
     * @param string $currentControllerName eg. 'Referers'
     * @param string $currentControllerAction eg. 'getKeywords'
     * @param string $apiMethodToRequestDataTable eg. 'Referers.getKeywords'
     * @param string $controllerActionCalledWhenRequestSubTable eg. 'getSearchEnginesFromKeywordId'
     * @param array  $defaultProperties
     */
    public function init($currentControllerName,
                         $currentControllerAction,
                         $apiMethodToRequestDataTable,
                         $controllerActionCalledWhenRequestSubTable = null,
                         $defaultProperties = array())
    {
        $this->currentControllerName = $currentControllerName;
        $this->currentControllerAction = $currentControllerAction;
        $this->viewProperties['subtable_controller_action'] = $controllerActionCalledWhenRequestSubTable;
        $this->idSubtable = Piwik_Common::getRequestVar('idSubtable', false, 'int');
        
        foreach ($defaultProperties as $name => $value) {
            $this->setViewProperty($name, $value);
        }
        
        $queryParams = Piwik_Url::getArrayFromCurrentQueryString();
        foreach ($this->getOverridableProperties() as $name) {
            if (isset($queryParams[$name])) {
                $this->setViewProperty($name, $queryParams[$name]);
            }
        }
        
        $this->viewProperties['show_footer_icons'] = ($this->idSubtable == false);
        $this->viewProperties['apiMethodToRequestDataTable'] = $apiMethodToRequestDataTable;
        
        $this->viewProperties['report_id'] = $currentControllerName . '.' . $currentControllerAction;
        $this->viewProperties['self_url'] = $this->getBaseReportUrl($currentControllerName, $currentControllerAction);
        
        if (!Piwik_PluginsManager::getInstance()->isPluginActivated('Goals')) {
            $this->viewProperties['show_goals'] = false;
        }
        
        // the exclude low population threshold value is sometimes obtained by requesting data.
        // to avoid issuing unecessary requests when display properties are determined by metadata,
        // we allow it to be a closure.
        if (isset($this->viewProperties['filter_excludelowpop_value'])
            && $this->viewProperties['filter_excludelowpop_value'] instanceof Closure
        ) {
            $function = $this->viewProperties['filter_excludelowpop_value'];
            $this->viewProperties['filter_excludelowpop_value'] = $function();
        }

        $this->loadDocumentation();
    }
    
    /**
     * Forces the View to use a given template.
     * Usually the template to use is set in the specific ViewDataTable_*
     * eg. 'CoreHome/templates/cloud'
     * But some users may want to force this template to some other value
     *
     * TODO: after visualization refactor, should remove this.
     * 
     * @param string $tpl eg .'@MyPlugin/templateToUse'
     */
    public function setTemplate($tpl)
    {
        $this->viewProperties['datatable_template'] = $tpl;
    }

    /**
     * Returns the View_Interface.
     * You can then call render() on this object.
     *
     * @return Piwik_View_Interface
     * @throws exception if the view object was not created
     */
    public function getView()
    {
        if (is_null($this->view)) {
            throw new Exception('The $this->view object has not been created.
					It should be created in the main() method of the Piwik_ViewDataTable_* subclass you are using.');
        }
        return $this->view;
    }

    public function getCurrentControllerAction()
    {
        return $this->currentControllerAction;
    }

    public function getCurrentControllerName()
    {
        return $this->currentControllerName;
    }

    public function getApiMethodToRequestDataTable()
    {
        return $this->viewProperties['apiMethodToRequestDataTable'];
    }

    public function getControllerActionCalledWhenRequestSubTable()
    {
        return $this->viewProperties['subtable_controller_action'];
    }

    /**
     * Returns the DataTable loaded from the API
     *
     * @return Piwik_DataTable
     * @throws exception if not yet defined
     */
    public function getDataTable()
    {
        if (is_null($this->dataTable)) {
            throw new Exception("The DataTable object has not yet been created");
        }
        return $this->dataTable;
    }

    /**
     * To prevent calling an API multiple times, the DataTable can be set directly.
     * It won't be loaded again from the API in this case
     *
     * @param $dataTable
     * @return void $dataTable Piwik_DataTable
     */
    public function setDataTable($dataTable)
    {
        $this->dataTable = $dataTable;
    }

    /**
     * Returns the defaut view properties for a report, if any.
     *
     * Plugins can associate callbacks with the ViewDataTable.getReportDisplayProperties
     * event to set the default properties of reports.
     *
     * @param string $apiAction
     * @return array
     */
    private static function getDefaultPropertiesForReport($apiAction)
    {
        $reportDisplayProperties = self::getAllReportDisplayProperties();
        return isset($reportDisplayProperties[$apiAction]) ? $reportDisplayProperties[$apiAction] : array();
    }

    /**
     * Returns the list of display properties for all available reports.
     * 
     * @return array
     */
    private static function getAllReportDisplayProperties()
    {
        if (self::$reportPropertiesCache === null) {
            self::$reportPropertiesCache = array();
            Piwik_PostEvent('ViewDataTable.getReportDisplayProperties', array(&self::$reportPropertiesCache));
        }

        return self::$reportPropertiesCache;
    }
    
    /**
     * Sets a view property by name. This function handles special view properties
     * like 'translations' & 'relatedReports' that store arrays.
     * 
     * @param string $name
     * @param mixed $value For array properties, $value can be a comma separated string.
     */
    private function setViewProperty($name, $value)
    {
        if (isset($this->viewProperties[$name])
            && is_array($this->viewProperties[$name])
            && is_string($value)
        ) {
            $value = Piwik::getArrayFromApiParameter($value);
        }
        
        if ($name == 'translations') {
            $this->viewProperties[$name] = array_merge($this->viewProperties[$name], $value);
        } else if ($name == 'relatedReports') {
            $this->addRelatedReports($reportTitle = false, $value);
        } else if ($name == 'filters') {
            foreach ($value as $filterInfo) {
                if (!is_array($filterInfo)) {
                    $this->queueFilter($filterInfo);
                } else {
                    @list($filter, $params, $isPriority) = $filterInfo;
                    $this->queueFilter($filter, $params, $isPriority);
                }
            }
        } else {
            $this->viewProperties[$name] = $value;
        }
    }

    /**
     * Function called by the ViewDataTable objects in order to fetch data from the API.
     * The function init() must have been called before, so that the object knows which API module and action to call.
     * It builds the API request string and uses Piwik_API_Request to call the API.
     * The requested Piwik_DataTable object is stored in $this->dataTable.
     */
    protected function loadDataTableFromAPI()
    {
        if (!is_null($this->dataTable)) {
            // data table is already there
            // this happens when setDataTable has been used
            return;
        }

        // we build the request (URL) to call the API
        $requestArray = $this->getRequestArray();

        // we make the request to the API
        $request = new Piwik_API_Request($requestArray);

        // and get the DataTable structure
        $dataTable = $request->process();

        $this->dataTable = $dataTable;
    }

    /**
     * Checks that the API returned a normal DataTable (as opposed to DataTable_Array)
     * @throws Exception
     * @return void
     */
    protected function checkStandardDataTable()
    {
        Piwik::checkObjectTypeIs($this->dataTable, array('Piwik_DataTable'));
    }

    /**
     * Hook called after the dataTable has been loaded from the API
     * Can be used to add, delete or modify the data freshly loaded
     *
     * @return bool
     */
    protected function postDataTableLoadedFromAPI()
    {
        if (empty($this->dataTable)) {
            return false;
        }

        // deal w/ table metadata
        if ($this->dataTable instanceof Piwik_DataTable) {
            $this->viewProperties['metadata'] = $this->dataTable->getAllTableMetadata();

            if (isset($this->viewProperties['metadata'][Piwik_DataTable::ARCHIVED_DATE_METADATA_NAME])) {
                $this->viewProperties['metadata'][Piwik_DataTable::ARCHIVED_DATE_METADATA_NAME] =
                    $this->makePrettyArchivedOnText();
            }
        }

        // First, filters that delete rows
        foreach ($this->queuedFiltersPriority as $filter) {
            $filterName = $filter[0];
            $filterParameters = $filter[1];
            $this->dataTable->filter($filterName, $filterParameters);
        }
        
        if (!$this->areGenericFiltersDisabled()) {
            // Second, generic filters (Sort, Limit, Replace Column Names, etc.)
            $requestArray = $this->getRequestArray();
            $request = Piwik_API_Request::getRequestArrayFromString($requestArray);

            if ($this->viewProperties['enable_sort'] === false) {
                $request['filter_sort_column'] = $request['filter_sort_order'] = '';
            }

            $genericFilter = new Piwik_API_DataTableGenericFilter($request);
            $genericFilter->filter($this->dataTable);
        }

        if (!$this->areQueuedFiltersDisabled()) {
            // Finally, apply datatable filters that were queued (should be 'presentation' filters that
            // do not affect the number of rows)
            foreach ($this->queuedFilters as $filter) {
                $filterName = $filter[0];
                $filterParameters = $filter[1];
                $this->dataTable->filter($filterName, $filterParameters);
            }
        }
        
        // default columns_to_display to label, nb_uniq_visitors/nb_visits if those columns exist in the
        // dataset. otherwise, default to all columns in dataset.
        if ($this->dataTable instanceof Piwik_DataTable) {
            $columns = $this->dataTable->getColumns();
            if (empty($this->viewProperties['columns_to_display'])) {
                if ($this->dataTableColumnsContains($columns, array('nb_visits', 'nb_uniq_visitors'))) {
                    $columnsToDisplay = array('label');
                    
                    // if unique visitors data is available, show it, otherwise just visits
                    if ($this->dataTableColumnsContains($columns, 'nb_uniq_visitors')) {
                        $columnsToDisplay[] = 'nb_uniq_visitors';
                    } else {
                        $columnsToDisplay[] = 'nb_visits';
                    }
                } else {
                    $columnsToDisplay = $columns;
                }

                $this->viewProperties['columns_to_display'] = array_filter($columnsToDisplay);
            }

            $this->removeEmptyColumnsFromDisplay();
        }

        return true;
    }

    /**
     * Returns true if generic filters have been disabled, false if otherwise.
     *
     * @return bool
     */
    private function areGenericFiltersDisabled()
    {
        // if disable_generic_filters query param is set to '1', generic filters are disabled
        if (Piwik_Common::getRequestVar('disable_generic_filters', '0', 'string') == 1) {
            return true;
        }

        // if $this->disableGenericFilters() was called, generic filters are disabled
        if (isset($this->viewProperties['disable_generic_filters'])
            && $this->viewProperties['disable_generic_filters'] === true
        ) {
            return true;
        }

        return false;
    }

    /**
     * Returns true if queued filters have been disabled, false if otherwise.
     *
     * @return bool
     */
    private function areQueuedFiltersDisabled()
    {
        return isset($this->viewProperties['disable_queued_filters'])
            && $this->viewProperties['disable_queued_filters'];
    }

    /**
     * Returns prettified and translated text that describes when a report was last updated.
     *
     * @return string
     */
    private function makePrettyArchivedOnText()
    {
        $dateText = $this->viewProperties['metadata'][Piwik_DataTable::ARCHIVED_DATE_METADATA_NAME];
        $date = Piwik_Date::factory($dateText);
        $today = mktime(0, 0, 0);
        if ($date->getTimestamp() > $today) {
            $elapsedSeconds = time() - $date->getTimestamp();
            $timeAgo = Piwik::getPrettyTimeFromSeconds($elapsedSeconds);

            return Piwik_Translate('CoreHome_ReportGeneratedXAgo', $timeAgo);
        }

        $prettyDate = $date->getLocalized("%longYear%, %longMonth% %day%") . $date->toString('S');
        return Piwik_Translate('CoreHome_ReportGeneratedOn', $prettyDate);
    }

    /**
     * @return string URL to call the API, eg. "method=Referers.getKeywords&period=day&date=yesterday"...
     */
    protected function getRequestArray()
    {
        // we prepare the array to give to the API Request
        // we setup the method and format variable
        // - we request the method to call to get this specific DataTable
        // - the format = original specifies that we want to get the original DataTable structure itself, not rendered
        $requestArray = array(
            'method' => $this->viewProperties['apiMethodToRequestDataTable'],
            'format' => 'original',
            'disable_generic_filters' => Piwik_Common::getRequestVar('disable_generic_filters', 1, 'int')
        );

        $toSetEventually = array(
            'filter_limit',
            'keep_summary_row',
            'filter_sort_column',
            'filter_sort_order',
            'filter_excludelowpop',
            'filter_excludelowpop_value',
            'filter_column',
            'filter_pattern',
            'disable_queued_filters',
        );

        foreach ($toSetEventually as $varToSet) {
            $value = $this->getDefaultOrCurrent($varToSet);
            if (false !== $value) {
                $requestArray[$varToSet] = $value;
            }
        }
        
        $segment = Piwik_API_Request::getRawSegmentFromRequest();
        if(!empty($segment)) {
            $requestArray['segment'] = $segment;
        }
        
        $requestArray = array_merge($requestArray, $this->viewProperties['request_parameters_to_modify']);
        
        return $requestArray;
    }

    /**
     * For convenience, the client code can call methods that are defined in a specific children class
     * without testing the children class type, which would trigger an error with a different children class.
     *
     * Example:
     *  ViewDataTable/Html.php defines a setColumnsToDisplay(). The client code calls this methods even if
     *  the ViewDataTable object is a ViewDataTable_Cloud instance (he doesn't know because of the factory()).
     *  But ViewDataTable_Cloud doesn't define the setColumnsToDisplay() method.
     *  Because we don't want to force users to test for the object type we simply catch these
     *  calls when they are not defined in the child and do nothing.
     *
     * @param string $function
     * @param array $args
     */
    public function __call($function, $args)
    {
    }

    /**
     * Returns array of properties, eg. "show_footer", "show_search", etc.
     *
     * @return array of boolean
     */
    protected function getViewProperties()
    {
        return $this->viewProperties;
    }

    /**
     * This functions reads the customization values for the DataTable and returns an array (name,value) to be printed in Javascript.
     * This array defines things such as:
     * - name of the module & action to call to request data for this table
     * - optional filters information, eg. filter_limit and filter_offset
     * - etc.
     *
     * The values are loaded:
     * - from the generic filters that are applied by default @see Piwik_API_DataTableGenericFilter.php::getGenericFiltersInformation()
     * - from the values already available in the GET array
     * - from the values set using methods from this class (eg. setSearchPattern(), setLimit(), etc.)
     *
     * @return array eg. array('show_offset_information' => 0, 'show_...
     */
    protected function getJavascriptVariablesToSet()
    {
        // build javascript variables to set
        $javascriptVariablesToSet = array();

        $genericFilters = Piwik_API_DataTableGenericFilter::getGenericFiltersInformation();
        foreach ($genericFilters as $filter) {
            foreach ($filter as $filterVariableName => $filterInfo) {
                // if there is a default value for this filter variable we set it
                // so that it is propagated to the javascript
                if (isset($filterInfo[1])) {
                    $javascriptVariablesToSet[$filterVariableName] = $filterInfo[1];

                    // we set the default specified column and Order to sort by
                    // when this javascript variable is not set already
                    // for example during an AJAX call this variable will be set in the URL
                    // so this will not be executed (and the default sorted not be used as the sorted column might have changed in the meanwhile)
                    if (false !== ($defaultValue = $this->getDefault($filterVariableName))) {
                        $javascriptVariablesToSet[$filterVariableName] = $defaultValue;
                    }
                }
            }
        }
        
        foreach ($this->viewProperties['custom_parameters'] as $name => $value) {
            $javascriptVariablesToSet[$name] = $value;
        }

        foreach ($_GET as $name => $value) {
            try {
                $requestValue = Piwik_Common::getRequestVar($name);
            } catch (Exception $e) {
                $requestValue = '';
            }
            $javascriptVariablesToSet[$name] = $requestValue;
        }

        // at this point there are some filters values we  may have not set,
        // case of the filter without default values and parameters set directly in this class
        // for example setExcludeLowPopulation
        // we go through all the $this->viewProperties array and set the variables not set yet
        foreach ($this->getJavaScriptProperties() as $name) {
            if (!isset($javascriptVariablesToSet[$name])
                && !empty($this->viewProperties[$name])
            ) {
                $javascriptVariablesToSet[$name] = $this->viewProperties[$name];
            }
        }

        if ($this->dataTable instanceof Piwik_DataTable) {
            // we override the filter_sort_column with the column used for sorting,
            // which can be different from the one specified (eg. if the column doesn't exist)
            $javascriptVariablesToSet['filter_sort_column'] = $this->dataTable->getSortedByColumnName();
            // datatable can return "2" but we want to write "nb_visits" in the js
            if (isset(Piwik_Metrics::$mappingFromIdToName[$javascriptVariablesToSet['filter_sort_column']])) {
                $javascriptVariablesToSet['filter_sort_column'] = Piwik_Metrics::$mappingFromIdToName[$javascriptVariablesToSet['filter_sort_column']];
            }
        }

        $javascriptVariablesToSet['module'] = $this->currentControllerName;
        $javascriptVariablesToSet['action'] = $this->currentControllerAction;
        if (!isset($javascriptVariablesToSet['viewDataTable'])) {
            $javascriptVariablesToSet['viewDataTable'] = $this->getViewDataTableId();
        }
        $javascriptVariablesToSet['controllerActionCalledWhenRequestSubTable'] = $this->viewProperties['subtable_controller_action'];

        if ($this->dataTable &&
            // Piwik_DataTable_Array doesn't have the method
            !($this->dataTable instanceof Piwik_DataTable_Array)
            && empty($javascriptVariablesToSet['totalRows'])
        ) {
            $javascriptVariablesToSet['totalRows'] = $this->dataTable->getRowsCountBeforeLimitFilter();
        }

        // we escape the values that will be displayed in the javascript footer of each datatable
        // to make sure there is no malicious code injected (the value are already htmlspecialchar'ed as they
        // are loaded with Piwik_Common::getRequestVar()
        foreach ($javascriptVariablesToSet as &$value) {
            if (is_array($value)) {
                $value = array_map('addslashes', $value);
            } else {
                $value = addslashes($value);
            }
        }

        $deleteFromJavascriptVariables = array(
            'filter_excludelowpop',
            'filter_excludelowpop_value',
        );
        foreach ($deleteFromJavascriptVariables as $name) {
            if (isset($javascriptVariablesToSet[$name])) {
                unset($javascriptVariablesToSet[$name]);
            }
        }

        $rawSegment = Piwik_API_Request::getRawSegmentFromRequest();
        if(!empty($rawSegment)) {
            $javascriptVariablesToSet['segment'] = $rawSegment;
        }

        return $javascriptVariablesToSet;
    }

    /**
     * Returns, for a given parameter, the value of this parameter in the REQUEST array.
     * If not set, returns the default value for this parameter @see getDefault()
     *
     * @param string $nameVar
     * @return string|mixed Value of this parameter
     */
    protected function getDefaultOrCurrent($nameVar)
    {
        if (isset($_GET[$nameVar])) {
            return Piwik_Common::sanitizeInputValue($_GET[$nameVar]);
        }
        $default = $this->getDefault($nameVar);
        return $default;
    }

    /**
     * Returns the default value for a given parameter.
     * For example, these default values can be set using the disable* methods.
     *
     * @param string $nameVar
     * @return mixed
     */
    protected function getDefault($nameVar)
    {
        if (!isset($this->viewProperties[$nameVar])) {
            return false;
        }
        return $this->viewProperties[$nameVar];
    }
    
    /**
     * Sets a set of extra request query parameters to be used when querying API data.
     * 
     * @param array $params
     */
    public function setRequestParametersToModify($params)
    {
        $this->viewProperties['request_parameters_to_modify'] += $params;
    }

    /**
     * The generic filters (limit, offset, sort by visit desc) will not be applied to this datatable.
     */
    public function disableGenericFilters()
    {
        $this->viewProperties['disable_generic_filters'] = true;
    }

    /**
     * The queued filters (replace column names, enhance column with percentage signs, add logo metadata information, etc.)
     * will not be applied to this datatable. They can be manually applied by calling applyQueuedFilters on the datatable.
     */
    public function disableQueuedFilters()
    {
        $this->viewProperties['disable_queued_filters'] = true;
    }

    /**
     * The "X-Y of Z" and the "< Previous / Next >"-Buttons won't be displayed under this table
     */
    public function disableOffsetInformationAndPaginationControls()
    {
        $this->viewProperties['show_offset_information'] = false;
        $this->viewProperties['show_pagination_control'] = false;
    }

    /**
     * The "< Previous / Next >"-Buttons won't be displayed under this table
     */
    public function disableShowPaginationControl()
    {
        $this->viewProperties['show_pagination_control'] = false;
    }

    /**
     * Ensures the limit dropdown will always be shown, even if pagination is disabled.
     */
    public function alwaysShowLimitDropdown()
    {
        $this->viewProperties['show_limit_control'] = true;
    }

    /**
     * The "X-Y of Z" won't be displayed under this table
     */
    public function disableOffsetInformation()
    {
        $this->viewProperties['show_offset_information'] = false;
    }

    /**
     * The search box won't be displayed under this table
     */
    public function disableSearchBox()
    {
        $this->viewProperties['show_search'] = false;
    }

    /**
     * Do not sort this table, leave it as it comes out of the API
     */
    public function disableSort()
    {
        $this->viewProperties['enable_sort'] = false;
    }

    /**
     * Do not show the footer icons (show all columns icon, "plus" icon)
     */
    public function disableFooterIcons()
    {
        $this->viewProperties['show_footer_icons'] = false;
    }

    /**
     * When this method is called, the output will not include the template datatable_footer
     */
    public function disableFooter()
    {
        $this->viewProperties['show_footer'] = false;
    }