octobercms/october · error · SystemException

Dropdown menu item command is not provided for item type :ty

Error message

Dropdown menu item command is not provided for item type :type

What it means

The same ItemDefinition constructor also requires a non-empty command for every non-separator item, because a menu item signals selection by emitting that command string to the UI. Without a command the item would be unclickable, so construction fails fast rather than producing a dead menu entry.

Source

Thrown at modules/backend/vuecomponents/dropdownmenu/ItemDefinition.php:90

    /**
     * @var string|null group
     */
    protected $group;

    /**
     * __construct
     */
    public function __construct($type, ?string $label = null, ?string $command = null)
    {
        $this->type = $type;

        if ($type != ItemDefinition::TYPE_SEPARATOR && !strlen($label)) {
            throw new SystemException('Dropdown menu item label is not provided for item type '.$type);
        }

        if ($type != ItemDefinition::TYPE_SEPARATOR && !strlen($command)) {
            throw new SystemException('Dropdown menu item command is not provided for item type '.$type);
        }

        $this->label = $label;
        $this->command = $command;
    }

    /**
     * Sets optional item key attribute
     */
    public function setKey(string $value)
    {
        $this->key = $value;
    }

    /**
     * setLinkHref
     */
    public function setLinkHref(string $value)

View on GitHub (pinned to b608633a7e)

Solutions

Provide the command as the third argument: new ItemDefinition(ItemDefinition::TYPE_BUTTON, 'Save', 'save:all').
Default missing dynamic commands, e.g. $command = $data['command'] ?? 'noop';
Confirm separator items actually use ItemDefinition::TYPE_SEPARATOR if they are meant to omit the command.

Example fix

// before
$item = new ItemDefinition(ItemDefinition::TYPE_LINK, 'Open list');

// after
$item = new ItemDefinition(ItemDefinition::TYPE_LINK, 'Open list', 'open:list');

Defensive patterns

Strategy: validation

Validate before calling

// Menu builder helper - validate commands coming from dynamic data
function makeItem($type, $label, $command)
{
    if ($type !== ItemDefinition::TYPE_SEPARATOR && !strlen(trim((string) $command))) {
        throw new InvalidArgumentException('Menu command missing for type ' . $type);
    }
    return new ItemDefinition($type, $label, $command);
}

Prevention

Default missing dynamic commands, e.g. $data['command'] ?? 'noop'
Use TYPE_SEPARATOR for dividers - the only command-less type
Keep handler names and the commands that emit them in one place

When it happens

Trigger: new ItemDefinition(ItemDefinition::TYPE_LINK, 'Open') with the third argument omitted; command strings built dynamically that end up as '' or null; swapping the label and command arguments.

Common situations: Renaming a handler and forgetting the menu item that emits it, leaving an empty string; building items from config arrays that lack a 'command' key; intending a separator but mistyping the type constant so the item is a regular type.

Related errors

AI-assisted analysis of octobercms/october@b608633a7e (2026-08-21). Data as JSON: /api/errors/6c72190ce4a5292b. Report an issue: GitHub.