octobercms/october · error · SystemException

Treeview branch grouping is only supported for the LIST disp

Error message

Treeview branch grouping is only supported for the LIST display mode

What it means

Error "Treeview branch grouping is only supported for the LIST display mode" thrown in octobercms/october.

Source

Thrown at modules/backend/vuecomponents/treeview/NodeDefinition.php:145

     */
    public function __construct(string $label, string $key)
    {
        $this->label = $label;
        $this->key = $key;
    }

    /**
     * Sets tree branch display mode - tree or list.
     * Only the root node display mode is considered.
     */
    public function setDisplayMode(string $value)
    {
        if (!in_array($value, [self::DISPLAY_MODE_TREE, self::DISPLAY_MODE_LIST])) {
            throw new SystemException('Invalid tree display mode: '.$value);
        }

        if ($this->groupBy) {
            throw new SystemException('Treeview branch grouping is only supported for the LIST display mode');
        }

        $this->displayMode = $value;

        return $this;
    }

    /**
     * Determines whether multiple nodes can be selected.
     * Only the root node property value is considered.
     */
    public function setMultiSelect(bool $value)
    {
        $this->multiSelect = $value;

        return $this;
    }

View on GitHub (pinned to b608633a7e)

When it happens

Trigger: Thrown at modules/backend/vuecomponents/treeview/NodeDefinition.php:145 when the library encounters an invalid state.

Common situations: See trigger scenarios.

AI-assisted analysis of octobercms/october@b608633a7e (2026-08-21). Data as JSON: /api/errors/e4f7282cfe649461. Report an issue: GitHub.