class MenuLinkBase

abstract class MenuLinkBase extends PluginBase implements MenuLinkInterface {
    
    /**
     * The list of definition values where an override is allowed.
     *
     * The keys are definition names. The values are ignored.
     *
     * @var array
     */
    protected $overrideAllowed = [];
    
    /**
     * {@inheritdoc}
     */
    public function getWeight() {
        // By default the weight is 0.
        if (!isset($this->pluginDefinition['weight'])) {
            $this->pluginDefinition['weight'] = 0;
        }
        return $this->pluginDefinition['weight'];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getMenuName() {
        return $this->pluginDefinition['menu_name'];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getProvider() {
        return $this->pluginDefinition['provider'];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getParent() {
        return $this->pluginDefinition['parent'];
    }
    
    /**
     * {@inheritdoc}
     */
    public function isEnabled() {
        return (bool) $this->pluginDefinition['enabled'];
    }
    
    /**
     * {@inheritdoc}
     */
    public function isExpanded() {
        return (bool) $this->pluginDefinition['expanded'];
    }
    
    /**
     * {@inheritdoc}
     */
    public function isResettable() {
        return FALSE;
    }
    
    /**
     * {@inheritdoc}
     */
    public function isTranslatable() {
        return (bool) $this->getTranslateRoute();
    }
    
    /**
     * {@inheritdoc}
     */
    public function isDeletable() {
        return (bool) $this->getDeleteRoute();
    }
    
    /**
     * {@inheritdoc}
     */
    public function getOptions() {
        return $this->pluginDefinition['options'] ?: [];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getMetaData() {
        return $this->pluginDefinition['metadata'] ?: [];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getRouteName() {
        return $this->pluginDefinition['route_name'] ?? '';
    }
    
    /**
     * {@inheritdoc}
     */
    public function getRouteParameters() {
        return $this->pluginDefinition['route_parameters'] ?? [];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getUrlObject($title_attribute = TRUE) {
        $options = $this->getOptions();
        if ($title_attribute && ($description = $this->getDescription())) {
            $options['attributes']['title'] = $description;
        }
        if (empty($this->pluginDefinition['url'])) {
            return new Url($this->getRouteName(), $this->getRouteParameters(), $options);
        }
        else {
            return Url::fromUri($this->pluginDefinition['url'], $options);
        }
    }
    
    /**
     * {@inheritdoc}
     */
    public function getFormClass() {
        return $this->pluginDefinition['form_class'];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getDeleteRoute() {
        return NULL;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getEditRoute() {
        return Url::fromRoute('menu_ui.link_edit', [
            'menu_link_plugin' => $this->getPluginId(),
        ]);
    }
    
    /**
     * {@inheritdoc}
     */
    public function getResetRoute() : Url|null {
        return NULL;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getTranslateRoute() {
        return NULL;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getOperations() : array {
        $operations = [];
        $operations['edit'] = [
            'title' => $this->t('Edit'),
            'url' => $this->getEditRoute(),
        ];
        // Links can either be reset or deleted, not both.
        if ($this->isResettable()) {
            $operations['reset'] = [
                'title' => $this->t('Reset'),
                'url' => $this->getResetRoute(),
            ];
        }
        elseif ($this->isDeletable()) {
            $operations['delete'] = [
                'title' => $this->t('Delete'),
                'url' => $this->getDeleteRoute(),
            ];
        }
        if ($this->isTranslatable()) {
            $operations['translate'] = [
                'title' => $this->t('Translate'),
                'url' => $this->getTranslateRoute(),
            ];
        }
        return $operations;
    }
    
    /**
     * {@inheritdoc}
     */
    public function deleteLink() {
        throw new PluginException("Menu link plugin with ID '{$this->getPluginId()}' does not support deletion");
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCacheMaxAge() {
        return Cache::PERMANENT;
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCacheContexts() {
        return [];
    }
    
    /**
     * {@inheritdoc}
     */
    public function getCacheTags() {
        return [];
    }

}