/**
 * Add a single editor extra plugin.
 *
 * @param  string $plugin
 * @return Zend_Dojo_Form_Element_Editor
 */
public function addExtraPlugin($plugin)
{
    $plugin = (string) $plugin;
    $extraPlugins = $this->getExtraPlugins();
    if (in_array($plugin, $extraPlugins)) {
        return $this;
    }

    $extraPlugins[] = (string) $plugin;
    $this->setDijitParam('extraPlugins', $extraPlugins);
    return $this;
}

/**
 * Add multiple extra plugins.
 *
 * @param  array $extraPlugins
 * @return Zend_Dojo_Form_Element_Editor
 */
public function addExtraPlugins(array $plugins)
{
    foreach ($plugins as $plugin) {
        $this->addExtraPlugin($plugin);
    }
    return $this;
}

/**
 * Overwrite many extra plugins at once.
 *
 * @param  array $plugins
 * @return Zend_Dojo_Form_Element_Editor
 */
public function setExtraPlugins(array $plugins)
{
    $this->clearExtraPlugins();
    $this->addExtraPlugins($plugins);
    return $this;
}

/**
 * Get all extra plugins.
 *
 * @return array
 */
public function getExtraPlugins()
{
    if (!$this->hasDijitParam('extraPlugins')) {
        return array();
    }
    return $this->getDijitParam('extraPlugins');
}

/**
 * Is a given extra plugin registered?
 *
 * @param  string $plugin
 * @return bool
 */
public function hasExtraPlugin($plugin)
{
    $extraPlugins = $this->getExtraPlugins();
    return in_array((string) $plugin, $extraPlugins);
}

/**
 * Remove a given extra plugin.
 *
 * @param  string $plugin
 * @return Zend_Dojo_Form_Element_Editor
 */
public function removeExtraPlugin($plugin)
{
    $extraPlugins = $this->getExtraPlugins();
    if (false === ($index = array_search($plugin, $extraPlugins))) {
        return $this;
    }
    unset($extraPlugins[$index]);
    $this->setDijitParam('extraPlugins', $extraPlugins);
    return $this;
}

/**
 * Clear all extra plugins.
 *
 * @return Zend_Dojo_Form_Element_Editor
 */
public function clearExtraPlugins()
{
    return $this->removeDijitParam('extraPlugins');
}