blob: 94accd6b1f9b095fda0079f7b86b866d88ffee01 [file] [log] [blame]
// Takes a root element and a list of ids of shadow host elements. Each id refers to a shadow host
// inside the previous id's shadow tree.
function getElementByShadowIds(root, ids) {
for (var i = 0; ;i++) {
var host = root.getElementById(ids[i]);
if (host == null) {
throw "No element found: i=" + i + " id=" + ids[i] + ". Root was " + root;
}
if (i == ids.length - 1) {
return host;
}
root = host.shadowRoot;
if (root == null) {
throw "No shadowRoot found: i=" + i + " id=" + ids[i] + ". Host was " + host;
}
}
}
// Installs a mininal custom element based on this template.
function installCustomElement(element_name, template_id) {
ceClass = class extends HTMLElement {
constructor() {
super();
var template = document
.getElementById(template_id)
.content;
this
.attachShadow({mode: 'open'})
.appendChild(template.cloneNode(true));
}
};
window.customElements.define(element_name, ceClass);
}