CssCollectionGrouper.php

<?php

namespace Drupal\advagg\Asset;

use Drupal\Core\Asset\AssetCollectionGrouperInterface;
use Drupal\Core\Asset\CssCollectionGrouper as CoreCssCollectionGrouper;
use Drupal\Core\Config\ConfigFactoryInterface;
use Drupal\Core\Extension\ModuleHandlerInterface;
use Drupal\Core\State\StateInterface;

/**
 * Groups CSS assets.
 */
class CssCollectionGrouper extends CoreCssCollectionGrouper implements AssetCollectionGrouperInterface {
    
    /**
     * A config object for the advagg configuration.
     *
     * @var \Drupal\Core\Config\Config
     */
    protected $config;
    
    /**
     * The AdvAgg file status state information storage service.
     *
     * @var \Drupal\Core\State\StateInterface
     */
    protected $advaggFiles;
    
    /**
     * Module handler service.
     *
     * @var \Drupal\Core\Extension\ModuleHandlerInterface
     */
    protected $moduleHandler;
    
    /**
     * Construct the AssetDumper instance.
     *
     * @param \Drupal\Core\Config\ConfigFactoryInterface $config_factory
     *   A config factory for retrieving required config objects.
     * @param \Drupal\Core\State\StateInterface $advagg_files
     *   The AdvAgg file status state information storage service.
     * @param \Drupal\Core\Extension\ModuleHandlerInterface $module_handler
     *   The module handler.
     */
    public function __construct(ConfigFactoryInterface $config_factory, StateInterface $advagg_files, ModuleHandlerInterface $module_handler) {
        $this->config = $config_factory->get('advagg.settings');
        $this->advaggFiles = $advagg_files;
        $this->moduleHandler = $module_handler;
    }
    
    /**
     * {@inheritdoc}
     *
     * Puts multiple items into the same group if they are groupable and if they
     * are for the same 'browsers' and 'inline'. Items of the 'file' type are
     * groupable if their 'preprocess' flag is TRUE, and items of the 'external'
     * type are never groupable.
     *
     * Also ensures that the process of grouping items does not change their
     * relative order. This requirement may result in multiple groups for the same
     * type, inline, media and browsers, depending on settings if needed to
     * accommodate other items in between.
     */
    public function group(array $css_assets) {
        if ($this->config
            ->get('core_groups')) {
            return parent::group($css_assets);
        }
        $combine_media = $this->config
            ->get('css.combine_media');
        $ie_limit_selectors = $this->config
            ->get('css.ie.limit_selectors');
        $ie_selector_limit = $this->config
            ->get('css.ie.selector_limit');
        if ($ie_limit_selectors) {
            $file_info = $this->advaggFiles
                ->getMultiple(array_column($css_assets, 'data'));
        }
        $groups = [];
        // If a group can contain multiple items, we track the information that must
        // be the same for each item in the group, so that when we iterate the next
        // item, we can determine if it can be put into the current group, or if a
        // new group needs to be made for it.
        $current_group_keys = NULL;
        // When creating a new group, we pre-increment $i, so by initializing it to
        // -1, the first group will have index 0.
        $i = -1;
        $selectors = 0;
        foreach ($css_assets as $item) {
            // The browsers for which the CSS item needs to be loaded is part of the
            // information that determines when a new group is needed, but the order
            // of keys in the array doesn't matter, and we don't want a new group if
            // all that's different is that order.
            ksort($item['browsers']);
            // If the item can be grouped with other items, set $group_keys to an
            // array of information that must be the same for all items in its group.
            // If the item can't be grouped with other items, set $group_keys to
            // FALSE. We put items into a group that can be aggregated together:
            // whether they will be aggregated is up to the _drupal_css_aggregate()
            // function or an
            // override of that function specified in hook_css_alter(), but regardless
            // of the details of that function, a group represents items that can be
            // aggregated. Since a group may be rendered with a single HTML tag, all
            // items in the group must share the same information that would need to
            // be part of that HTML tag.
            switch ($item['type']) {
                case 'file':
                    // Group file items if their 'preprocess' flag is TRUE.
                    // Help ensure maximum reuse of aggregate files by only grouping
                    // together items that share the same 'group' value.
                    if ($item['preprocess']) {
                        $group_keys = [
                            $item['group'],
                            $item['browsers'],
                        ];
                        if (!$combine_media) {
                            $group_keys[] = $item['media'];
                        }
                        if (isset($item['inline'])) {
                            $group_keys[] = $item['inline'];
                        }
                        if ($ie_limit_selectors) {
                            if (isset($file_info[$item['data']]['parts'])) {
                                foreach ($file_info[$item['data']]['parts'] as $part) {
                                    $i++;
                                    $groups[$i] = $item;
                                    unset($groups[$i]['data'], $groups[$i]['weight'], $groups[$i]['basename']);
                                    $groups[$i]['items'] = [
                                        0 => $item,
                                    ];
                                    $groups[$i]['items'][0]['data'] = $part['path'];
                                    $selectors = $part['selectors'];
                                }
                            }
                            else {
                                $selectors += $file_info[$item['data']]['linecount'];
                                if ($selectors > $ie_selector_limit) {
                                    $group_keys['break'] = TRUE;
                                }
                            }
                        }
                    }
                    else {
                        $group_keys = FALSE;
                        if ($ie_limit_selectors && $file_info[$item['data']]['linecount'] > $ie_selector_limit) {
                            foreach ($file_info[$item['data']]['parts'] as $part) {
                                $i++;
                                $groups[$i] = $item;
                                unset($groups[$i]['data'], $groups[$i]['weight'], $groups[$i]['basename']);
                                $groups[$i]['items'] = [
                                    0 => $item,
                                ];
                                $groups[$i]['items'][0]['data'] = $part['path'];
                            }
                            continue;
                        }
                    }
                    break;
                case 'external':
                    // Do not group external items.
                    $group_keys = FALSE;
                    break;
            }
            // If the group keys don't match the most recent group we're working with,
            // then a new group must be made.
            if ($group_keys !== $current_group_keys) {
                if ($ie_limit_selectors) {
                    if ($item['type'] == 'file' && $item['preprocess']) {
                        $selectors = $file_info[$item['data']]['linecount'];
                    }
                    else {
                        $selectors = 0;
                    }
                }
                unset($group_keys['break']);
                $i++;
                // Initialize the new group with the same properties as the first item
                // being placed into it. The item's 'data', 'weight' and 'basename'
                // properties are unique to the item and should not be carried over to
                // the group.
                $groups[$i] = $item;
                unset($groups[$i]['data'], $groups[$i]['weight'], $groups[$i]['basename']);
                if ($combine_media && $item['type'] == 'file' && $item['preprocess']) {
                    unset($groups[$i]['media']);
                }
                $groups[$i]['items'] = [];
                $current_group_keys = $group_keys ? $group_keys : NULL;
            }
            // Add the item to the current group.
            $groups[$i]['items'][] = $item;
        }
        // Run hook so other modules can modify the data.
        // Call hook_advagg_asset_grouping_alter().
        $type = 'css';
        $this->moduleHandler
            ->alter('advagg_aggregate_grouping', $groups, $type);
        return $groups;
    }

}