Open a HTML Document dialog in Add-on SDK

gistfile1.js

/* Open a plain dialog */

const { getActiveTab, setTabURL } = require('sdk/tabs/utils');
const { open } = require('sdk/window/helpers');

const { data } = require('sdk/self');
const url = data.url('foo.html');

open("", {
  features: {
    toolbar: false,
    resizable: true,
    scrollbars: true,
    width: 200,
    height: 400
  }
}).then(window => setTabURL(getActiveTab(window), url));

/* If a content script needs to be attached to the dialog */

const { getActiveTab, setTabURL, getTabId } = require('sdk/tabs/utils');
const { open } = require('sdk/window/helpers');

const { data } = require('sdk/self');
const url = data.url('foo.html');

const tabs = require('sdk/tabs');

open("", {
  features: {
    toolbar: false,
    resizable: true,
    scrollbars: true,
    width: 200,
    height: 400
  }
}).then(window => {
  let xulTab = getActiveTab(window);
  let id = getTabId(xulTab);

  tabs.on('ready', function ready(tab) {
    if (tab.id === id) {
      tabs.removeListener('ready', ready);
      tab.attach({
        contentScript: 'alert("hello")'
      });
    }
  });

  setTabURL(xulTab, url);
});