$definitions = $this->blockManager->getDefinitionsForContexts($this->contextRepository->getAvailableContexts());
// Order by category, and then by admin label.
$definitions = $this->blockManager->getSortedDefinitions($definitions);
+ // Filter out definitions that are not intended to be placed by the UI.
+ $definitions = array_filter($definitions, function (array $definition) {
+ return empty($definition['_block_ui_hidden']);
+ });
$region = $request->query->get('region');
$weight = $request->query->get('weight');