developers.home-assistant/docs/lovelace_custom_card.md

title
Lovelace: Custom Cards

Lovelace is our new approach to defining your user interface for Home Assistant. We offer a lot of built-in cards, but you're not just limited to the ones that we decided to include in the Lovelace UI. You can build and use your own!

API

You define your custom card as a custom element. It's up to you to decide how to render your DOM inside your element. You can use Polymer, Angular, Preact or any other popular framework (except for React – more info on React here).

const element = document.createElement('some-custom-card');

Home Assistant will call setConfig(config) when the configuration changes (rare). If you throw an exception if the configuration is invalid, Lovelace will render an error card to notify the user.

try {
  element.setConfig(config);
} catch (err) {
  showErrorCard(err.message, config);
}

Home Assistant will set the hass property when the state of Home Assistant changes (frequent). Whenever the state changes, the component will have to update itself to represent the latest state.

element.hass = hass;

Your card can define a getCardSize method that returns the size of your card as a number. A height of 1 is equivalent to 50 pixels. This will help Home Assistant distribute the cards evenly over the columns. A card size of 1 will be assumed if the method is not defined.

if ('getCardSize' in element) {
  return element.getCardSize();
} else {
  return 1;
}

Defining your card

Create a new file in your Home Assistant config dir as <config>/www/content-card-example.js and put in the following contents:

class ContentCardExample extends HTMLElement {
  set hass(hass) {
    if (!this.content) {
      const card = document.createElement('ha-card');
      card.header = 'Example card';
      this.content = document.createElement('div');
      this.content.style.padding = '0 16px 16px';
      card.appendChild(this.content);
      this.appendChild(card);
    }

    const entityId = this.config.entity;
    const state = hass.states[entityId];
    const stateStr = state ? state.state : 'unavailable';

    this.content.innerHTML = `
      The state of ${entityId} is ${stateStr}!
      <br><br>
      <img src="http://via.placeholder.com/350x150">
    `;
  }

  setConfig(config) {
    if (!config.entity) {
      throw new Error('You need to define an entity');
    }
    this.config = config;
  }

  // The height of your card. Home Assistant uses this to automatically
  // distribute all cards over the available columns.
  getCardSize() {
    return 3;
  }
}

customElements.define('content-card-example', ContentCardExample);

Referencing your new card

In our example card we defined a card with the tag content-card-example (see last line), so our card type will be custom:content-card-example. And because you created the file in your <config>/www directory, it will be accessible in your browser via the url /local/ (if you have recently added the www folder you will need to re-start home assistant for files to be picked up).

# Example Lovelace configuration
resources:
  - url: /local/content-card-example.js
    type: js
views:
- name: Example
  cards:
  - type: "custom:content-card-example"
    entity: input_boolean.switch_tv

Advanced example

Resources to load in Lovelace can be imported as a JS script, an HTML import or as a JS module import. Below is an example of a custom card using JS modules that does all the fancy things.

Create a new file in your Home Assistant config dir as <config>/www/wired-cards.js and put in the following contents:

import "https://unpkg.com/wired-card@0.8.1/wired-card.js?module";
import "https://unpkg.com/wired-toggle@0.8.0/wired-toggle.js?module";
import {
  LitElement,
  html,
  css
} from "https://unpkg.com/lit-element@2.0.1/lit-element.js?module";

function loadCSS(url) {
  const link = document.createElement("link");
  link.type = "text/css";
  link.rel = "stylesheet";
  link.href = url;
  document.head.appendChild(link);
}

loadCSS("https://fonts.googleapis.com/css?family=Gloria+Hallelujah");

class WiredToggleCard extends LitElement {
  static get properties() {
    return {
      hass: {},
      config: {}
    };
  }

  render() {
    return html`
      <wired-card elevation="2">
        ${this.config.entities.map(ent => {
          const stateObj = this.hass.states[ent];
          return stateObj
            ? html`
                <div class="state">
                  ${stateObj.attributes.friendly_name}
                  <wired-toggle
                    .checked="${stateObj.state === "on"}"
                    @change="${ev => this._toggle(stateObj)}"
                  ></wired-toggle>
                </div>
              `
            : html`
                <div class="not-found">Entity ${ent} not found.</div>
              `;
        })}
      </wired-card>
    `;
  }

  setConfig(config) {
    if (!config.entities) {
      throw new Error("You need to define entities");
    }
    this.config = config;
  }

  // The height of your card. Home Assistant uses this to automatically
  // distribute all cards over the available columns.
  getCardSize() {
    return this.config.entities.length + 1;
  }

  _toggle(state) {
    this.hass.callService("homeassistant", "toggle", {
      entity_id: state.entity_id
    });
  }

  static get styles() {
    return css`
      :host {
        font-family: "Gloria Hallelujah", cursive;
      }
      wired-card {
        background-color: white;
        padding: 16px;
        display: block;
        font-size: 18px;
      }
      .state {
        display: flex;
        justify-content: space-between;
        padding: 8px;
        align-items: center;
      }
      .not-found {
        background-color: yellow;
        font-family: sans-serif;
        font-size: 14px;
        padding: 8px;
      }
      wired-toggle {
        margin-left: 8px;
      }
    `;
  }
}
customElements.define("wired-toggle-card", WiredToggleCard);

And for your configuration:

# Example Lovelace configuration
resources:
  - url: /local/wired-cards.js
    type: module
views:
- name: Example
  cards:
  - type: "custom:wired-toggle-card"
    entities:
      - input_boolean.switch_ac_kitchen
      - input_boolean.switch_ac_livingroom
      - input_boolean.switch_tv