Brightcove Player Sample: Play/Pause Video from iframe Parent

Product(s)
Video Cloud
Brightcove Player
Role(s)
Player Developer
Topic(s)
Advanced HTML/CSS
Code Samples

In this topic, you will learn how to use a button on the parent page of an iframe player to play or pause the video in the iframe player.

Player example

Click either the play or pause button, which is part of the iframe's parent page, to see it initiate play/pause of the video in the iframe player.

See the Pen 18192-play-video-iframe-parent by Brightcove Learning Services (@rcrooks1969) on CodePen.

View the source code.

Using the CodePen

Here are some tips to effectively use the above CodePen:

  • Toggle the actual display of the player by clicking the Result button.
  • Click the HTML/CSS/JS buttons to display ONE of the code types.
  • Later in this document the logic, flow and styling used in the application will be discussed in the Player/HTML configuration, Application flow and Application styling sections. The best way to follow along with the information in those sections is to:
    1. Click the EDIT ON CODEPEN button in the CodePen and have the code available in one browser/browser tab.
    2. In CodePen, adjust what code you want displayed. You can change the width of different code sections within CodePen.
    3. View the Player/HTML configuration, Application flow and/or Application styling sections in another browser/browser tab. You will now be able to follow the code explanations and at the same time view the code.

Development sequence

Here is the recommended development sequence:

  1. Use the In-Page embed player implementation to test the functionality of your player, plugin and CSS (if CSS is needed)
  2. Put the plugin's JavaScript and CSS into separate files for local testing
  3. Deploy the plugin code and CSS to your server once you have worked out any errors
  4. Use Studio to add the plugin and CSS to your player
  5. Replace the In-Page embed player implementation if you determine that the iframe implementation is a better fit (detailed in next section)

For details about these steps, review the Quick Start: Plugin Development guide.

iframe or In-Page embed

When developing enhancements for the Brightcove player you will need to decide if the code is a best fit for the iframe or In-Page embed implementation. The best practice recommendation is to build a plugin for use with an iframe implementation. The advantages of using the iframe player are:

  • No collisions with existing JavaScript and/or CSS
  • Automatically responsive
  • The iframe eases use in social media apps (or whenever the video will need to "travel" into other apps)

Although integrating the In-Page embed player can be more complex, there are times when you will plan your code around that implementation. To generalize, this approach is best when the containing page needs to communicate to the player. Specifically, here are some examples:

  • Code in the containing page needs to listen for and act on player events
  • The player uses styles from the containing page
  • The iframe will cause app logic to fail, like a redirect from the containing page

Even if your final implementation does not use the iframe code, you can still use the In-Page embed code with a plugin for your JavaScript and a separate file for your CSS. This encapsulates your logic so that you can easily use it in multiple players.

API/Plugin resources used

API Methods
play()
pause()

The code also uses JavaScript's postMessage() method in the parent page, and addEventListener() in the iframe.

Player/HTML configuration

This section details any special configuration needed during player creation. In addition, other HTML elements that must be added to the page, beyond the in-page embed player implementation code, are described.

Player configuration

The point of this sample is to communicate with the iframe version of the player, hence that player implementation code is used.

Other HTML

Two HTML buttons are added to the page.

Application flow

The basic logic behind this application is:

  • When the Play or Pause button is clicked, JavaScript's postMessage() method sends a corresponding string value into the iframe.
  • The iframe uses the addEventListener() event to listen for the message, then acts upon it accordingly.

Create correct URL and object so postMessage() can be used

Find the code which is labeled:

// ### Create functions that post either play or pause ###

The postMessage() method is used to send a message to the iframe's Window object. The first argument is the data passed as part of the event. (In this case it is simply a string, but can be an object.) The second argument specifies the origin of the iframe. You can use the '*' wildcard to have the event sent to any content in the iframe, no matter where it came from, but this is considered a poor security practice. Using theURL variable (either http://players.brightcove.net or https://players.brightcove.net) as the argument means the event will only be sent to the iframe if the content originated from that URL.

Listen for message in iframe

Find the code which is labeled:

// ### This is the plugin code ###

The purpose of the sample is to show how you can communicate with the iframe from the parent, so using the in-page code implementation first makes no sense here. The best practice approach to associate code with an iframe player implementation is using a plugin, so that is what is done here. For convenience, the plugin code is shown commented in the CodePen.

The key method here is JavaScript's addEventListener() method. The postMessage() method dispatches an event of type message (that is always the event name with postMessage()). The defined event handler is controlVideo (the second argument). In the controlVideo() event handler, an if statement is used to check the value of the data passed by postMessage(), in this case either playVideo or pauseVideo. Based on the value of the data passed in, the video is either played or paused.

Application styling

The plugin's CSS simple hides the big play button to encourage the use of the play and pause buttons.

Plugin code

Normally when converting the JavaScript into a Brightcove Player plugin nominal changes are needed. One required change is to replace the standard use of the ready() method with the code that defines a plugin.

Here is the very commonly used start to JavaScript code that will work with the player:

videojs.getPlayer('myPlayerID').ready(function() {
  var myPlayer = this;
  ...
});

You will change the first line to use the standard syntax to start a Brightcove Player plugin:

videojs.registerPlugin('pluginName', function(options) {
  var myPlayer = this;
  ...
});

As mentioned earlier, you can see the plugin's JavaScript code in this document's corresponding GitHub repo: listen-for-parent.js.

Using the plugin with a player

Once you have the plugin's CSS and JavaScript files stored in an Internet accessible location, you can use the plugin with a player. In Studio's PLAYERS module you can choose a player, then in the PLUGINS section add the URLs to the CSS and JavaScript files, and also add the Name and Options, if options are needed.