/**
* Returns a generator selected by the user from a multilevel console menu.
*/
protected function selectGenerator(InputInterface $input, OutputInterface $output)
{
// Narrow menu tree according to the active menu items.
$active_menu_tree = $this->menuTree;
foreach ($this->activeMenuItems as $active_menu_item) {
$active_menu_tree = $active_menu_tree[$active_menu_item];
}
// The $active_menu_tree can be either an array of child menu items or
// the TRUE value indicating that the user reached the final menu point and
// active menu items contain the actual command name.
if (is_array($active_menu_tree)) {
$subtrees = $command_names = [];
// We build $choices as an associative array to be able to find
// later menu items by respective labels.
foreach ($active_menu_tree as $menu_item => $subtree) {
$menu_item_label = $this->createMenuItemLabel($menu_item, is_array($subtree));
if (is_array($subtree)) {
$subtrees[$menu_item] = $menu_item_label;
} else {
$command_names[$menu_item] = $menu_item_label;
}
}
asort($subtrees);
asort($command_names);
// Generally the choices array consists of the following parts:
// - Reference to the parent menu level.
// - Sorted list of nested menu levels.
// - Sorted list of commands.
$choices = ['..' => '..'] + $subtrees + $command_names;
$question = new ChoiceQuestion('<title>Select generator:</title>', array_values($choices));
$question->setPrompt(' >>> ');
$answer_label = $this->getHelper('question')->ask($input, $output, $question);
$answer = array_search($answer_label, $choices);
if (!$answer) {
throw new \UnexpectedValueException(sprintf('"%s" menu item was not found', $answer_label));
}
if ($answer == '..') {
// Exit the application if the user choices zero key
// on the top menu level.
if (count($this->activeMenuItems) == 0) {
return NULL;
}
// Set the menu one level higher.
array_pop($this->activeMenuItems);
} else {
// Set the menu one level deeper.
$this->activeMenuItems[] = $answer;
}
return $this->selectGenerator($input, $output);
} else {
return implode(':', $this->activeMenuItems);
}
}