/**
* Compact a JSON-LD document according a supplied context
*
* In contrast to {@link compact()}, this method assumes that the input
* has already been expanded.
*
* @param array $input The JSON-LD document to
* compact.
* @param null|string|object|array $context The context.
* @param null|array|object $options Options to configure the
* compaction process.
* @param bool $alwaysGraph If set to true, the resulting
* document will always explicitly
* contain the default graph at
* the top-level.
*
* @return object The compacted JSON-LD document.
*
* @throws JsonLdException
*/
private static function doCompact($input, $context = null, $options = null, $alwaysGraph = false)
{
if (null !== $context) {
$context = Processor::loadDocument($context);
}
if (is_object($context) && property_exists($context, '@context')) {
$context = $context->{'@context'};
}
if (is_object($context) && 0 === count(get_object_vars($context))) {
$context = null;
} elseif (is_array($context) && 0 === count($context)) {
$context = null;
}
$activectx = array('@base' => $options->base);
$processor = new Processor($options);
$processor->processContext($context, $activectx);
$inversectx = $processor->createInverseContext($activectx);
$processor->compact($input, $activectx, $inversectx);
$compactedDocument = new Object();
if (null !== $context) {
$compactedDocument->{'@context'} = $context;
}
if (false === is_array($input) || 0 === count($input)) {
if (false === $alwaysGraph) {
$compactedDocument = (object) ((array) $compactedDocument + (array) $input);
return $compactedDocument;
}
if (false === is_array($input)) {
$input = array($input);
}
}
$graphKeyword = isset($inversectx['@graph']['term']) ? $inversectx['@graph']['term'] : '@graph';
$compactedDocument->{$graphKeyword} = $input;
return $compactedDocument;
}