<script>
        require([
            'mage/url',
            'Magento_Ui/js/block-loader'
        ], function(url, blockLoader) {
            blockLoader("<?php /* @escapeNotVerified */ echo $block->getViewFileUrl('images/loader-1.gif'); ?>");
            return url.setBaseUrl('<?php /* @escapeNotVerified */ echo $block->getBaseUrl();?>');
        })
    </script>