Brightcove Player Sample: Back and Forward Buttons

In this topic, you will learn how to place buttons in the controlbar that rewind and advance the video a specified number of seconds.

Player example

After you start the video playing, you can click the back or forward buttons (actually clickable <div> elements) to jump five seconds either way. The five seconds can be easily modified in the code with one change, if you wish to change the number of seconds jumped.

See the Pen Back and Forward Buttons by Brightcove Learning Services (@rcrooks1969) on CodePen.

Source code

View the complete solution on GitHub.

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 Step-by-Step: 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
$()
currentTime()
duration()

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

No special configuration is required for the Brightcove Player you create for this sample.

Other HTML

No other HTML elements are added to the page.

Application flow

The basic logic behind this application is:

  • Create HTML <div> tags to hold the buttons.
  • Assign IDs to the <div> tags.
  • Assign images of buttons to the <div> tags.
  • Insert the <div> tags into the controlbar.
  • Add click event handlers to the <div> tags to actually change playback.

Create HTML <div> tags

Find the code which is labeled:

// ### Create divs for buttons ###

Two <div> tags are created, one for each button.

Assign IDs to the <div> tags

Find the code which is labeled:

// ### Assign IDs for later element manipulation ###

An ID is assigned to each <div> tag so they can be addressed and changes can be dynamically made to them later in the code.

Assign images of buttons to the <div> tags

Find the code which is labeled:

// ### Assign properties to elements and assign to parents ###

Appropriate images are dynamically assigned to <img> tags, then those images assigned to the <div> tags.

Insert the <div> tags into the controlbar

Find the code which is labeled:

// ### Get controlbar and insert elements ###

A reference is obtained to the control bar using the $() method (no relation to jQuery) in this line of code:

controlBar = myPlayer.$('.vjs-control-bar');

This is equivalent to using this JavaScript:

document.getElementsByClassName('vjs-control-bar')[0];

The advantage of the $() method is that it can be scoped to the player, so multiple players won't cause an issue. Also it returns the single element, not an array.

Once you have a reference to the controlbar, a reference to the element containing the volume control is obtained as a reference where to place the buttons. Finally, both <div> tags are inserted into the control bar.

Add event handlers

Find the code which is labeled:

// ### Add event handlers to jump back or forward ###

The logic of the event handlers is quite straight forward. The only details are making sure the time is not set to negative values on one end, or above the duration on the other.

Application styling

The CSS controls the size and positioning of the images in the <div> tags.

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: back-forward-buttons.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.