octobercms/october · error · SystemException

getDependencies() must return an array: %s

Error message

getDependencies() must return an array: %s

What it means

VueMaker::registerVueComponent() asks each registered Vue component for its dependency components via getDependencies() and requires the result to be a PHP array before recursing. If a component overrides getDependencies() and returns null, a string, or any non-array, registration aborts with this SystemException naming the offending class. The base VueComponentBase returns an array, so only a bad override triggers it.

Source

Thrown at modules/backend/traits/VueMaker.php:50

    protected $vueComponentClasses = [];

    /**
     * registerVueComponent to be loaded when the action view renders.
     * @param string $className
     */
    public function registerVueComponent($className)
    {
        if ($this->isVueComponentRegistered($className)) {
            return;
        }

        $component = $this->makeVueComponent($className);
        $this->vueComponents[] = $component;
        $this->vueComponentClasses[$className] = true;

        $requiredComponents = $component->getDependencies();
        if (!is_array($requiredComponents)) {
            throw new SystemException(sprintf('getDependencies() must return an array: %s', $className));
        }

        foreach ($requiredComponents as $className) {
            if (!$this->isVueComponentRegistered($className)) {
                $this->registerVueComponent($className);
            }
        }
    }

    /**
     * outputVueComponentTemplates outputs templates and ESM component registration.
     * This method:
     * 1. Renders text/template scripts for each component
     * 2. Imports ESM modules and registers them as Vue components with template injection
     */
    public function outputVueComponentTemplates()
    {
        $registrations = $this->getVueComponentRegistrations();

View on GitHub (pinned to b608633a7e)

Solutions

1. Make getDependencies() always return an array — add `return [];` as the final statement.
2. Normalize external values: `return is_array($deps) ? $deps : [];` when dependencies come from config.
3. Check for early returns in the override that skip returning a value.

Example fix

// before
public function getDependencies()
{
    if ($this->advanced) {
        return [ChartComponent::class];
    }
}

// after
public function getDependencies()
{
    if ($this->advanced) {
        return [ChartComponent::class];
    }

    return [];
}

// Inside your Vue component, normalize before returning
public function getDependencies()
{
    $deps = $this->calculateDependencies(); // may be null on edge paths

    return is_array($deps) ? $deps : [];
}

When it happens

Trigger: Calling $this->registerVueComponent('...') (or booting a controller that registers Vue components) where the component's getDependencies() returns null or a non-array — e.g. an override with a conditional return but no final `return [];`, or a dependency property that was never initialized.

Common situations: Dependency-ordering overrides that forget the default branch; returning a config value that is sometimes null; refactoring away from a method that always returned an array.

Related errors

• Vue component class not found: %s
• Vue component class must be a descendant of Backend\Classes\
• A widget class name ':name' has not been registered
• Dropdown menu item label is not provided for item type :type
• Dropdown menu item command is not provided for item type :ty

AI-assisted analysis of octobercms/october@b608633a7e (2026-08-21). Data as JSON: /api/errors/def4da64fac4457c. Report an issue: GitHub.