Home assistant iframe error

On the left side of Home Assistant are a number of different panels. Most users are familiar with the default panels, like “Overview,” a.k.a. the Lovelace dashboard — but it’s possible to do a lot more with home assistant custom panels.

For a breakdown of each panel in the screenshot above, see the log cabin -> smart home retrofit.

Multiple Lovelace Dashboards

As of version 1.0.7, Home Assistant supports creating more than one Lovelace dashboard, configurable at /config/lovelace/dashboards. Each panel is essentially an entirely new, stand-alone dashboard.

I like using panels more than tabs because I find it significantly easier to navigate. In the image above, you can see how Security, Temperature, etc. are broken out into separate panels. Hopefully, we’ll soon be able to re-order the panels as well.

Taking it a step further, it’s possible to add iframes as panels. This is useful for embedding other services on the network, like the Iris/Mopidy music player seen in the screenshot above.

[Example] Simple IFrame

The simplest possible example of a custom panel is a single file residing at panels/custom-iframe.html. This custom iframe panel does not render a top bar, and ensures that the iframe fills the entire viewport without overflowing. In short, it makes the embedded webpage take up the entire right half of the screen.

<dom-module id='custom-iframe'>
  <template>
    <style include="ha-style">
        iframe {
          overflow: hidden;
          position: absolute;
          left: 0;
          right: 0;
          top: 0;
          bottom: 0;
          border: 0;
          width: 100%;
          height: calc(100%);
          background-color: var(--primary-background-color);
        }
      </style>
      <iframe
        src="[[panel.config.url]]"
        sandbox="allow-forms allow-popups allow-pointer-lock allow-same-origin allow-scripts"
        allowfullscreen="true"
        webkitallowfullscreen="true"
        mozallowfullscreen="true"
      ></iframe>
  </template>
</dom-module>

<script>
Polymer({
  is: 'custom-iframe',
  properties: {
    hass: {
      type: Object,
    },
    panel: {
      type: Object,
    }
  },
});
</script>

How it Works

To use the above custom IFrame panel, add the following to configuration.yaml:

panel_custom:
  - name: custom-iframe
    sidebar_title: "Custom Iframe"
    url_path: my-custom-iframe
    config:
      url: "http://my-test-site.com"

Replace the URL with the site you wish to view. By default, Home Assistant will infer from the name to load panels/custom-iframe.html (from the last section). If you wish to reuse the panel code, you can explicitly declare the location of the html file with webcomponent_path: "panels/iris.html".

However, the preferred way to build modern custom panels is to use a module.

[Example] Using a Module

Instead of the webcomponent_path (or no path at all), the preferred way to create a custom panel is to use a module. Here is a boilerplate HTMLElement (which could reside at www/custom-panel-example.js):

class CustomPanelExample extends HTMLElement {
  constructor () {
    super()
    this._shadow = this.attachShadow( { mode: 'open' } )
  }

  render() {
    // Sample of changing the HTML contents of the panel.
    this._shadow.innerHTML = '<div>' + JSON.stringify(this._config) + '</div>';
  }

  set panel(panel) {
    // Called once with the exact contents from the YAML definition
    console.log('custom panel config', panel.config);
    this._config = panel.config;
    this.render();
  }

  set hass(hass) { 
    // This function is called frequently, containing the HA state.
    console.log('entity states', hass.states);
  }
}

customElements.define('custom-panel-example', CustomPanelExample);

Which could then be used with the following configuration:

panel_custom:
  - name: custom-panel-example.js
    module_url: "/local/custom-panel-example.js"
    sidebar_title: 'Example'
    url_path: example
    config:
      hello: 'world!'

If all goes well, the panel should show {"hello": "world!"}.

[Example] Reusable Full-Screen iFrame Module

This example shows how to create a single module that may be used multiple times. This allows you have just one module file, but create as many custom panels as you need. Each panel will be a full-screen iframe. First, create www/iframe-fullscreen.js:

class IframeFullscreen extends HTMLElement {
  constructor () {
    super()
    this._shadow = this.attachShadow( { mode: 'open' } )
  }
  render() {
    this._shadow.innerHTML = `<style include="ha-style">
        iframe {
          border: 0;
          width: 100%;
          height: calc(100%);
          background-color: var(--primary-background-color);
        }
      </style>
      <iframe
        src="`+this._config.url+`"
        sandbox="allow-forms allow-popups allow-pointer-lock allow-same-origin allow-scripts"
        allowfullscreen="true"
        webkitallowfullscreen="true"
        mozallowfullscreen="true"
      ></iframe>`;
  }
  set panel(panel) {
    this._config = panel.config;
    this.render();
  }

}
customElements.define('iframe-fullscreen', IframeFullscreen);

Then add the configuration:

panel_custom:
  - name: iframe-fullscreen
    module_url: "/local/iframe-fullscreen.js"
    sidebar_title: 'iframe1'
    url_path: iframe1
    config:
      url: "https://node-workshop.snowy-cabin.com/"

  - name: iframe-fullscreen
    module_url: "/local/iframe-fullscreen.js"
    sidebar_title: 'iframe2'
    url_path: iframe2
    config:
      url: "https://node-doorbell.snowy-cabin.com/"

Notice how each of the panels have the same name, which matches the custom element definition in the module. In other words, the name field is used for the name of the component to load (and does not need to be unique). In this screenshot, you can see how this lets me load a tab for two different Node-RED instances:

[Example] Replacing History with Grafana

I like using Grafana much more than the built-in History features because I pipe all of my various metrics through Prometheus. It’s a much more feature-rich graphing application than the built-in History. One simple example: it’s easy to change the time range with Grafana.

It also means I can use a single visualization tool to graph much more than just Home Assistant data. Home Assistant’s Prometheus integration is not spectacular, but it is enough to get the data into Grafana and shut off the default “History” feature.

Looking for help bulidng Grafana charts for Home Assistant to fully replace the History card?

One way to achieve this is to click on any panel in Grafana and choose “share,” and then use that URL in a lovelace iframe card:

However, this is very inflexible. Multiple iframes must be loaded (one for each panel). The panels need to be manually configured, one by one, in lovelace. Instead, it can be convenient to have access to an entire Grafana dashboard.

With the custom iframe panel from the last section created, a custom panel can be added to configuration.yaml:

panel_custom:
  - name: custom-iframe
    sidebar_title: Grafana
    sidebar_icon: mdi:home-analytics
    url_path: grafana
    require_admin: true
    config:
      url: !secret grafana_dashboard

The grafana_dashboard URL can simply be a URL to any dashboard. You can also set the query parameter &kiosk to remove the chrome from Grafana. More tips on running Grafana in Docker/Kubernetes are available if you get stuck.

To remove the default panels (Map, Logbook, and History) from Home Assisstant, first remove the default_config entry from configuration.yaml and then re-add each of the components which it loads (except for those you wish to exclude, of course).