npm package: @guaclive/videojs-chromecast
Description: video.js plugin for casting to chromecast
Author: Jeremy Thomerson
Latest version: 1.13.1

# Silvermine VideoJS Chromecast Plugin


## What is it?

A plugin for [videojs](http://videojs.com/) versions 6+ that adds a button to the control
bar which will cast videos to a Chromecast.


## How do I use it?

The `@standardbroadcast/videojs-chromecast` plugin includes 3 types of assets: javascript, CSS,
and images.

You can either build the plugin locally and use the assets that are output from the build
process directly, or you can install the plugin as an npm module, include the
javascript and SCSS source in your project using a Common-JS module loader and SASS build
process, and copy the images from the image source folder to your project.

Note that regardless of whether you are using this plugin via the pre-built JS or as a
module, the Chromecast framework will need to be included after the plugin. For example:

```html
<script src="https://unpkg.com/video.js@6.1.0/dist/video.js"></script>
<script src="./dist/videojs-chromecast.min.js"></script>
<script type="text/javascript" src="https://www.gstatic.com/cv/js/sender/v1/cast_sender.js?loadCastFramework=1"></script>
```

### Building the plugin locally

   1. Either clone this repository or install the `@standardbroadcast/videojs-chromecast` module
      using `npm install @standardbroadcast/videojs-chromecast`.
   2. Ensure that `@standardbroadcast/videojs-chromecast`'s `devDependencies` are installed by
      running `npm install` from within the `videojs-chromecast` folder.
   3. Run `grunt build` to build and copy the javascript, CSS and image files to the
      `videojs-chromecast/dist` folder.
   4. Copy the plugin's files from the `dist` folder into your project as needed.
   5. Ensure that the images in the `dist/images` folder are accessible at `./images/`,
      relative to where the plugin's CSS is located. If, for example, your CSS is located
      at `https://example.com/plugins/videojs-chromecast.css`, then the
      plugin's images should be located at `https://example.com/plugins/images/`.
   6. Follow the steps in the "Configuration" section below.

Note: when adding the plugin's javascript to your web page, include the
`videojs-chromecast.min.js` javascript file in your HTML *after* loading
Video.js. The plugin's built javascript file expects there to be a reference to Video.js
at `window.videojs` and will throw an error if it does not exist.

### Initialization options

   * **`preloadWebComponents`** (default: `false`) - The Chromecast framework relies on the
    `webcomponents.js` polyfill when a browser does not have `document.registerElement` in
     order to create the `<google-cast-button>` custom component (which is not used by this
     plugin).  If you are using jQuery, this polyfill must be loaded and initialized before
     jQuery is initialized. Unfortunately, the Chromecast framework loads the
     `webcomponents.js` polyfill via a dynamically created `<script>` tag. This causes a race
     condition (see #17). Also, including `webcomponents.js` anywhere on the page will break
     jQuery's fix for bubbling some events to `document` (e.g. `onchange` events for
     `<select>`, see #21).  Setting `preloadWebComponents` to `true` will "fix" these 2
     problems by (1) making this plugin add the `webcomponents` polyfill synchronously when
     the polyfill is needed and (2) using the `webcomponents-lite.js` version as it does not
     include the shadow DOM polyfills, but still provides the `registerElement` polyfill that
     the Chromecast framework needs. If you use the `preloadWebComponents: true` option, you
     should make sure that this plugin is loaded before jQuery. Then include the Chromecast
     framework after this plugin as you normally would.

  **Note:** There is a caveat to using the `preloadWebComponents` setting.
  Because the Chromecast plugin uses the shadow DOM to create the
  `<google-cast-button>` custom component, **the `<google-cast-button>` custom
  component may partly render, but it will not be functional**. This tag is not
  used by this plugin. However if you must use this tag elsewhere, you should
  not use the `preloadWebComponents` flag.

  tl;dr: if you use jQuery, you should use the `preloadWebComponents: true` option in
  this plugin.

#### Providing initialization options via `require()`

If requiring this plugin via NPM, any desired initialization options can be supplied to
the constructor function exported by the module. For example:

```js
require('@standardbroadcast/videojs-chromecast')(videojs, { preloadWebComponents: true });
```

#### Providing initialization options via `<script>`

If using the prebuilt JS, the initialization options can be provided via
`window.SILVERMINE_VIDEOJS_CHROMECAST_CONFIG`. Note that these options need to be set
before the `<script>` tag to include the plugin.

```html
<script>
   window.SILVERMINE_VIDEOJS_CHROMECAST_CONFIG = {
      preloadWebComponents: true,
   };
</script>
<script src="path/to/videojs-chromecast.js"></script>
```

### Configuration

Once the plugin has been loaded and registered, configure it and add it to your Video.js
player using Video.js' plugin configuration option (see the section under the heading
"Setting up a Plugin" on [Video.js' plugin documentation page][videojs-docs].

**Important: In addition to defining plugin configuration, you are required to define the
player's `techOrder` option, setting `'chromecast'` as the first Tech in the list.** Below
is an example of the minimum required configuration for the Chromecast plugin to function:

```js
var options;

options = {
   controls: true,
   techOrder: [ 'chromecast', 'html5' ], // You may have more Tech, such as Flash or HLS
   plugins: {
      chromecast: {}
   }
};

videojs(document.getElementById('myVideoElement'), options);
```

Please note that even if you choose not to use any of the configuration options, you must
either provide a `chromecast` entry in the `plugins` option for Video.js to initialize the
plugin for you:

```js
options = {
   plugins: {
      chromecast: {}
   }
};
```

or you must initialize the plugin manually:

```js
var player = videojs(document.getElementById('myVideoElement'));

player.chromecast(); // initializes the Chromecast plugin
```

#### Configuration options

##### Plugin configuration

   * **`plugins.chromecast.receiverAppID`** - the string ID of a custom [Chromecast receiver
     app][cast-receiver] to use. Defaults to the [default Media Receiver ID][def-cast-id].
   * **`plugins.chromecast.addButtonToControlBar`** - a `boolean` flag that tells the plugin
     whether or not it should automatically add the Chromecast button to the Video.js
     player's control bar component. Defaults to `true`.
   * **`plugins.chromecast.buttonPositionIndex`** - a zero-based number specifying the index
     of the Chromecast button among the control bar's child components (if
     `addButtonToControlBar` is set to `true`). By default the Chromecast Button is added as
     the last child of the control bar. A value less than 0 puts the button at the specified
     position from the end of the control bar. Note that it's likely not all child components
     of the control bar are visible.
   * **`plugins.chromecast.credentials`** - string with credentials identyfing the user.

##### Chromecast Tech configuration

   * **`chromecast.requestTitleFn`** - a function that this plugin calls when it needs a
     string that will be the title shown in the UI that is shown when a Chromecast session
     is active and connected. When the this plugin calls the `requestTitleFn`, it passes it
     the [current `source` object][player-source] and expects a string in return. If nothing
     is returned or if this option is not defined, no title will be shown.
   * **`chromecast.requestSubtitleFn`** - a function that this plugin calls when it needs a
     string that will be the sub-title shown in the UI that is shown when a Chromecast
     session is active and connected. When the this plugin calls the `requestSubtitleFn`, it
     passes it the [current `source` object][player-source] and expects a string in return.
     If nothing is returned or if this option is not defined, no sub-title will be shown.
   * **`chromecast.requestCustomDataFn`** - a function that this plugin calls when it needs
     an object that contains custom information necessary for a Chromecast receiver app when
     a session is active and connected. When the this plugin calls the `requestCustomDataFn`,
     it passes it the [current `source` object][player-source] and expects an object in return.
     If nothing is returned or if this option is not defined, no custom data will be sent.
     This option is intended to be used with a [custom receiver][custom-receiver] application
     to extend its default capabilities.
   * **`chromecast.requestQueueItemChangeFn`** - a function that this plugin calls, when `MEDIA_INFO_CHANGED` event is triggered, it passes `MediaInfoItem` as a parameter, from this event `event.value.entity` can be extracted to check what is the next item that should be played.
   * **`chromecast.onChangeSubtitleTrackFn`** - a function that this plugin calls, when a caption was changed by Chromecast device it passes an object {name: string} containing the name of the subtitle, or it passes `null` when captions were turned off.


Here is an example configuration object that makes full use of all required and optional
configuration:

```js
var titles, subtitles, customData, options;

titles = {
   'https://example.com/videos/video-1.mp4': 'Example Title',
   'https://example.com/videos/video-2.mp4': 'Example Title2',
};

subtitles = {
   'https://example.com/videos/video-1.mp4': 'Subtitle',
   'https://example.com/videos/video-2.mp4': 'Subtitle2',
};

customData = {
   'https://example.com/videos/video-1.mp4': { 'customColor': '#0099ee' },
   'https://example.com/videos/video-2.mp4': { 'customColor': '#000080' },
};

options = {
   // Must specify the 'chromecast' Tech first
   techOrder: ['chromecast', 'html5'], // Required
   // Configuration for the Chromecast Tech
   chromecast: {
      requestTitleFn: function (source) {
         // Not required
         return titles[source.url];
      },
      requestSubtitleFn: function (source) {
         // Not required
         return subtitles[source.url];
      },
      requestCustomDataFn: function (source) {
         // Not required
         return customData[source.url];
      },
      requestSubtitleFn: function (track) {
         // Not required
         if (track) {
            changeSubtitleTrack(track.name);
         } else {
            changeSubtitleTrack('off');
         }
      },
      requestQueueItemChangeFn: function (event) {
         // Not required
         if (event.value) {
            playNextItemFromQueue(event.value.entity);
         }
      },
   },
   plugins: {
      chromecast: {
         receiverAppID: '1234', // Not required
         addButtonToControlBar: false, // Defaults to true
         credentials: 'token', // not required
      },
   },
};
```

##### Localization

The `ChromecastButton` component has one translated string: "Open Chromecast menu". The
"Open Chromecast menu" string appears in both of the standard places for Button component
accessibility text: inside the `.vjs-control-text` span and as the `<button>` element's
`title` attribute.

To localize the Chromecast button text, follow the steps in the
[Video.js Languages tutorial][videojs-translation] to add an `"Open Chromecast menu"` key
to the map of translation strings.

### Using the npm module

If you are using a module loader such as Browserify or Webpack, first install
`@standardbroadcast/videojs-chromecast` using `npm install`. Then, use
`require('@standardbroadcast/videojs-chromecast')` to require `@standardbroadcast/videojs-chromecast`
into your project's source code. `require('@standardbroadcast/videojs-chromecast')` returns a
function that you can use to register the plugin with videojs by passing in a reference to
`videojs`:

```js
var videojs = require('video.js');

// Initialize the Chromecast plugin
require('standardbroadcast/videojs-chromecast')(videojs);
```

Then, follow the steps in the "Configuration" section above.

### Using the CSS and images

If you are using SCSS in your project, you can simply reference the plugin's main SCSS
file in your project's SCSS:

```scss
@import "path/to/node_modules/@standardbroadcast/videojs-chromecast/src/scss/videojs-chromecast";
```

Optionally, you can override the SCSS variables that contain the paths to the icon
image files:

   * **`$icon-chromecast--default`** - the path to the icon image that is displayed when the
     Chromecast button is in its normal, default state. Defaults to
     `"images/ic_cast_white_24dp.png"`.
   * **`$icon-chromecast--hover`** - the path to the icon image that is displayed when the
     user hovers over the Chromecast button when it is in its normal, default state. Defaults
     to `"images/ic_cast_white_24dp.png"`.
   * **`$icon-chromecast-casting`** - the path to the icon image that is displayed when the
     Chromecast button is in the "casting" state (when a Chromecast session is active and
     connected). Defaults to `"images/ic_cast_connected_white_24dp.png"`.
   * **`$icon-chromecast-casting--hover`** - the path to the icon image that is displayed
     when the user hovers over the Chromecast button when it is in the "casting" state (when
     a Chromecast session is active and connected). Defaults to
     `"images/ic_cast_connected_white_24dp.png"`.
   * **`$chromecast-icon-size`** - the width and height of the icon (the button and icon is
     a square). Defaults to `12px`.
   * **`$chromecast-title-font-size`** - the font size of the title on the screen that is
     shown while a Chromecast session is active and connected. Defaults to `22px`.
   * **`$chromecast-subtitle-font-size`** - the font size of the sub-title on the screen
     that is shown while a Chromecast session is active and connected. Defaults to `18px`.
   * **`$chromecast-poster-width`** - the width of the poster image on the screen that that
     is shown while a Chromecast session is active and connected. Defaults to `100px`.
   * **`$chromecast-poster-max-height`** - the maximum height of the poster image on the
     screen that is shown while a Chromecast session is active and connected.
     Defaults to `180px`.


#### Images

The plugin's images are located at `videojs-chromecast/src/images`. If you have
not overridden the icon image path variables in the SCSS, then copy the images from the
`src/images` folder to a folder that is accessible at `./images/`, relative to where the
plugin's CSS is located. If, for example, your CSS is located at
`https://example.com/plugins/videojs-chromecast.css`, then the plugin's images
should be located at `https://example.com/plugins/images/`.

In addition, the `ic_cast_white_24dp.png` icon image that is used as the default icon for
all four button states ("default", "default + hover", "casting", "casting + hover"), the `images`
folder contains grey, black, and blue versions of the icons.


### Events

   *`chromecastConnected`: Triggers when Chromecast connected
   *`chromecastDisconnected`: Triggers when Chromecast disconnected
   *`chromecastDevicesAvailable`: Triggers on state change when Chromecast devices are available
   *`chromecastDevicesUnavailable`: Triggers on state change when Chromecast devices are unavailable
   *`chromecastRequested`: Triggers when the user has requested Chromecast playback using this
     plugin's Chromecast button

## How do I contribute?

We genuinely appreciate external contributions. See [our extensive
documentation][contributing] on how to contribute.


## License

This software is released under the MIT license. See [the license file](LICENSE) for more
details.

[videojs-docs]: http://docs.videojs.com/tutorial-plugins.html
[videojs-translation]: http://docs.videojs.com/tutorial-languages.html
[cast-receiver]: https://developers.google.com/cast/docs/receiver_apps
[def-cast-id]: https://developers.google.com/cast/docs/receiver_apps#default
[player-source]: http://docs.videojs.com/Player.html#currentSource
[custom-receiver]: https://developers.google.com/cast/docs/custom_receiver
[contributing]: https://github.com/silvermine/silvermine-info#contributing