annotate core/lib/Drupal/Core/Asset/JsCollectionGrouper.php @ 19:fa3358dc1485 tip

Add ndrum files
author Chris Cannam
date Wed, 28 Aug 2019 13:14:47 +0100
parents 4c8ae668cc8c
children
rev   line source
Chris@0 1 <?php
Chris@0 2
Chris@0 3 namespace Drupal\Core\Asset;
Chris@0 4
Chris@0 5 /**
Chris@0 6 * Groups JavaScript assets.
Chris@0 7 */
Chris@0 8 class JsCollectionGrouper implements AssetCollectionGrouperInterface {
Chris@0 9
Chris@0 10 /**
Chris@0 11 * {@inheritdoc}
Chris@0 12 *
Chris@0 13 * Puts multiple items into the same group if they are groupable and if they
Chris@0 14 * are for the same browsers. Items of the 'file' type are groupable if their
Chris@0 15 * 'preprocess' flag is TRUE. Items of the 'external' type are not groupable.
Chris@0 16 *
Chris@0 17 * Also ensures that the process of grouping items does not change their
Chris@0 18 * relative order. This requirement may result in multiple groups for the same
Chris@0 19 * type and browsers, if needed to accommodate other items in between.
Chris@0 20 */
Chris@0 21 public function group(array $js_assets) {
Chris@0 22 $groups = [];
Chris@0 23 // If a group can contain multiple items, we track the information that must
Chris@0 24 // be the same for each item in the group, so that when we iterate the next
Chris@0 25 // item, we can determine if it can be put into the current group, or if a
Chris@0 26 // new group needs to be made for it.
Chris@0 27 $current_group_keys = NULL;
Chris@0 28 $index = -1;
Chris@0 29 foreach ($js_assets as $item) {
Chris@0 30 // The browsers for which the JavaScript item needs to be loaded is part
Chris@0 31 // of the information that determines when a new group is needed, but the
Chris@0 32 // order of keys in the array doesn't matter, and we don't want a new
Chris@0 33 // group if all that's different is that order.
Chris@0 34 ksort($item['browsers']);
Chris@0 35
Chris@0 36 switch ($item['type']) {
Chris@0 37 case 'file':
Chris@0 38 // Group file items if their 'preprocess' flag is TRUE.
Chris@0 39 // Help ensure maximum reuse of aggregate files by only grouping
Chris@0 40 // together items that share the same 'group' value.
Chris@0 41 $group_keys = $item['preprocess'] ? [$item['type'], $item['group'], $item['browsers']] : FALSE;
Chris@0 42 break;
Chris@0 43
Chris@0 44 case 'external':
Chris@0 45 // Do not group external items.
Chris@0 46 $group_keys = FALSE;
Chris@0 47 break;
Chris@0 48 }
Chris@0 49
Chris@0 50 // If the group keys don't match the most recent group we're working with,
Chris@0 51 // then a new group must be made.
Chris@0 52 if ($group_keys !== $current_group_keys) {
Chris@0 53 $index++;
Chris@0 54 // Initialize the new group with the same properties as the first item
Chris@0 55 // being placed into it. The item's 'data' and 'weight' properties are
Chris@0 56 // unique to the item and should not be carried over to the group.
Chris@0 57 $groups[$index] = $item;
Chris@0 58 unset($groups[$index]['data'], $groups[$index]['weight']);
Chris@0 59 $groups[$index]['items'] = [];
Chris@0 60 $current_group_keys = $group_keys ? $group_keys : NULL;
Chris@0 61 }
Chris@0 62
Chris@0 63 // Add the item to the current group.
Chris@0 64 $groups[$index]['items'][] = $item;
Chris@0 65 }
Chris@0 66
Chris@0 67 return $groups;
Chris@0 68 }
Chris@0 69
Chris@0 70 }