assets = [];
$this->assets_map = [];
}
public function append( $handle, $uri, $dependencies = [], $version = '', $options = [] ) {
if ( ! array_key_exists( $handle, $this->assets_map ) ) {
$this->assets_map[ $handle ] = [
'uri' => $uri . ( $version ? '?ver=' . $version : '' ),
'options' => $options,
];
$this->assets[ $handle ] = $dependencies;
}
return $this;
}
public function assets_map() {
return $this->assets_map;
}
public function priority_queue() {
$graph = [];
$in_degree = [];
foreach ( $this->assets as $handle => $dependencies ) {
if ( ! array_key_exists( $handle, $in_degree ) ) {
$in_degree[ $handle ] = 0;
}
foreach ( $dependencies as $dependency ) {
if ( ! array_key_exists( $dependency, $graph ) ) {
$graph[ $dependency ] = [];
}
$graph[ $dependency ][] = $handle;
$in_degree[ $handle ]++;
if ( ! array_key_exists( $dependency, $in_degree ) ) {
$in_degree[ $dependency ] = 0;
}
}
}
$queue = new \SplQueue();
foreach ( $in_degree as $handle => $count ) {
if ( 0 === $count ) {
$queue->enqueue( $handle );
}
}
$priority_queue = [];
while ( ! $queue->isEmpty() ) {
$current = $queue->dequeue();
$priority_queue[] = $current;
if ( ! array_key_exists( $current, $graph ) ) {
continue;
}
foreach ( $graph[ $current ] as $next ) {
$in_degree[ $next ]--;
if ( 0 === $in_degree[ $next ] ) {
$queue->enqueue( $next );
}
}
}
return $priority_queue;
}
}