Method loadhistory

/**
 * Method to load a row from version history
 *
 * @return  boolean  True if the record can be loaded, False if it cannot.
 *
 * @since   4.0.0
 */
public function loadhistory()
{
    $model = $this->getModel();
    $table = $model->getTable();
    $historyId = $this->input->getInt('version_id', null);
    if (!$model->loadhistory($historyId, $table)) {
        $this->setMessage($model->getError(), 'error');
        $this->setRedirect(Route::_('index.php?option=' . $this->option . '&view=' . $this->view_list . $this->getRedirectToListAppend(), false));
        return false;
    }
    // Determine the name of the primary key for the data.
    if (empty($key)) {
        $key = $table->getKeyName();
    }
    $recordId = $table->{$key};
    // To avoid data collisions the urlVar may be different from the primary key.
    $urlVar = empty($this->urlVar) ? $key : $this->urlVar;
    // Access check.
    if (!$this->allowEdit(array($key => $recordId), $key)) {
        $this->setMessage(Text::_('JLIB_APPLICATION_ERROR_EDIT_NOT_PERMITTED'), 'error');
        $this->setRedirect(Route::_('index.php?option=' . $this->option . '&view=' . $this->view_list . $this->getRedirectToListAppend(), false));
        $table->checkIn();
        return false;
    }
    $this->setRedirect(Route::_('index.php?option=' . $this->option . '&view=' . $this->view_item . $this->getRedirectToItemAppend($recordId, $urlVar), false));
    if (!$table->check() || !$table->store()) {
        $this->setMessage($table->getError(), 'error');
        return false;
    }
    $this->setMessage(Text::sprintf('JLIB_APPLICATION_SUCCESS_LOAD_HISTORY', $model->getState('save_date'), $model->getState('version_note')));
    // Invoke the postSave method to allow for the child class to access the model.
    $this->postSaveHook($model);
    return true;
}