Untitled

<!DOCTYPE html>
<html>

<head>
    <title></title>
    <meta charset="UTF-8">
    <link rel="import" href="component.html">

</head>

<body>
    <tag-name></tag-name>
</body>

</html>

<template>
    <style></style>
    <div>test</div>
</template>
<script>
    customElements.define('tag-name', class extends HTMLElement {

        constructor() {
            super();
            /*var tmpl = document.querySelector('link[href$="component.html"]').import
                .querySelector('template').content.cloneNode(true);*/


            var scripts = document.getElementsByTagName('script');
            var currentScript = scripts[scripts.length - 1];
            var tmpl = currentScript.previousSibling.content.cloneNode(true);
            this.attachShadow({
                mode: 'open'
            }).appendChild(tmpl);
        }

    });

</script>