CssCollectionGrouper.php
Same filename in other branches
Namespace
Drupal\Core\AssetFile
-
core/
lib/ Drupal/ Core/ Asset/ CssCollectionGrouper.php
View source
<?php
namespace Drupal\Core\Asset;
/**
* Groups CSS assets.
*/
class CssCollectionGrouper implements AssetCollectionGrouperInterface {
/**
* {@inheritdoc}
*
* Puts multiple items into the same group if they are groupable and if they
* are for the same 'media' and 'browsers'. 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, media, and browsers, if needed to accommodate other items in between.
*/
public function group(array $css_assets) {
$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.
$i = -1;
foreach ($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.
$group_keys = $item['preprocess'] ? [
$item['type'],
$item['group'],
$item['media'],
$item['browsers'],
] : FALSE;
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) {
$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']);
$groups[$i]['items'] = [];
$current_group_keys = $group_keys ? $group_keys : NULL;
}
// Add the item to the current group.
$groups[$i]['items'][] = $item;
}
return $groups;
}
}
Classes
Title | Deprecated | Summary |
---|---|---|
CssCollectionGrouper | Groups CSS assets. |
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