Filtering.Custom Filter (Advanced Version)

        protected function doGetCustomTemplate($type, $part, $mode, &$result, &$params)
        {
            if ($part == PagePart::GridToolbar && $mode == PageMode::ViewAll) {
                $result = 'custom_advanced_filter_grid_toolbar.tpl';
                
                $sql =
                    'SELECT ' .
                    '    FLOOR(MIN(life_expectancy)) as min_life_expectancy,' .
                    '    CEILING(MAX(life_expectancy)) as max_life_expectancy ' .
                    'FROM v_filtering_custom_filter2';
                $queryResult = array();
                $this->GetConnection()->ExecQueryToArray($sql, $queryResult);
                $minLifeExpectancy = $queryResult[0]['min_life_expectancy'];
                $maxLifeExpectancy = $queryResult[0]['max_life_expectancy'];
            
                $lifeExpectancyFilter = array(
                    'min' => $minLifeExpectancy,
                    'max' => $maxLifeExpectancy
                );
                if (isset($_SESSION['lifeExpectancyFilter'])) {
                    $lifeExpectancyFilter = array_merge($lifeExpectancyFilter, $_SESSION['lifeExpectancyFilter']);     
                } 
            
                $params['MinLifeExpectancy'] = $minLifeExpectancy;
                $params['MaxLifeExpectancy'] = $maxLifeExpectancy;
                $params['LifeExpectancyFilter'] = $lifeExpectancyFilter;
                
                $lifeExpectancyFilterActive = isset($_SESSION['lifeExpectancyFilter']);
                $params['LifeExpectancyFilterActive'] = $lifeExpectancyFilterActive;
                if ($lifeExpectancyFilterActive) {
                   $params['LifeExpectancyFilterAsString'] = 
                       sprintf('Life expectancy Is Between %d And %d years', 
                           $lifeExpectancyFilter['min'], $lifeExpectancyFilter['max']
                       );
                }    
            }
        }

        protected function DoPrepare() {
            // handling custom filter parameters
            $lifeExpectancyFilter = array(
                'min' => -1,
                'max' => -1
            );
               
            if (GetApplication()->isGetValueSet('lifeExpectancyFilter')) {
                $lifeExpectancyFilterValue = GetApplication()->GetGETValue('lifeExpectancyFilter');
                if (is_array($lifeExpectancyFilterValue)) {
                    $lifeExpectancyFilter = array_merge($lifeExpectancyFilter, $lifeExpectancyFilterValue);
                }
            } elseif (isset($_SESSION['lifeExpectancyFilter'])) {
                $lifeExpectancyFilter = array_merge($lifeExpectancyFilter, $_SESSION['lifeExpectancyFilter']);
            }
            
            if ($lifeExpectancyFilter['min'] !== -1 && $lifeExpectancyFilter['max'] !== -1) {
                $this->dataset->AddCustomCondition(
                    sprintf('life_expectancy >= %d AND life_expectancy <= %d', 
                        $lifeExpectancyFilter['min'], $lifeExpectancyFilter['max']
                    )    
                );
                $_SESSION['lifeExpectancyFilter'] = $lifeExpectancyFilter;
            } else {
                unset($_SESSION['lifeExpectancyFilter']);
            }
            
            // auxiliary code
            $this->setDescription(file_get_contents("external_data/doc/filtering_custom_filter_advanced.html"));
            
            $this->setDetailedDescription(
                '<br>' .
                '<div id="on-get-custom-template" class="event-code">' .
                    extractMethodCode($this, 'doGetCustomTemplate') . '</div>' .
                '<div id="on-prepare-page" class="event-code">' .
                    extractMethodCode($this, 'doPrepare') . '</div>' .
                '<div id="on-after-page-load" class="event-code">' .
                    extractClientEventCode($this, 'OnAfterPageLoad') . '</div>' .
                '<div id="custom-grid-toolbar" style="display: none;">' .
                    extractTemplateFileCode('components/templates/custom_templates/custom_advanced_filter_grid_toolbar.tpl') . 
                '</div>' .
                '<div id="custom-advanced-filter" style="display: none;">' .
                    extractTemplateFileCode('components/templates/custom_templates/custom_advanced_filter.tpl') . 
                '</div>'    
            );
        }

// OnAfterPageLoad event body
 function initCustomFilter() {
    var contentHtml = $('#custom_filter_content').html();
    var $form = $('.js-custom-filter-container').first();

    $('.js-reset-custom-filter').on('click', function() {
        window.location = $.query.set('lifeExpectancyFilter', '');
        return false;
    });

    $form.find('a.js-filter-trigger').each(function (i, el) {
        var $a = $(el);
        var $originalContent = $a.next('.js-content');

        var popover = $a.webuiPopover({
            trigger: 'click',
            backdrop: true,
            content: ''
        }).data('plugin_webuiPopover');

        $a.on('show.webui.popover', function () {
            var $content = $(contentHtml);
            $content.find('.js-content').html($originalContent.html());

            popover.$contentElement
                .html($content.prop('outerHTML'))
                .find('.js-apply').on('click', function () {
                    $originalContent.replaceWith(popover.$contentElement.clone());
                    popover.hide();
                    $form.trigger('submit');
                });

            popover.$contentElement.find('.close').on('click', function () {
                popover.hide();
            });

        });
    });

};

initCustomFilter();