videojs-per-source-behaviors



A video.js plugin for enhancing a player with behaviors related to changing media sources.

Maintenance Status: Stable

- Why?
- Installation
- Usage
-


`

$3

When using with Browserify, install videojs-per-source-behaviors via npm and require the plugin as you would any other module.

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

// The actual plugin function is exported by this module, but it is also
// attached to the Player.prototype; so, there is no need to assign it
// to a variable.
require('videojs-per-source-behaviors');

var player = videojs('my-video');

player.perSourceBehaviors();
`

$3

When using with RequireJS (or another AMD library), get the script in whatever way you prefer and require the plugin as you normally would:

`js
require(['video.js', 'videojs-per-source-behaviors'], function(videojs) {
var player = videojs('my-video');

player.perSourceBehaviors();
});
`

API

Once the plugin is invoked on a player - by calling player.perSourceBehaviors() - it begins firing a new event, gains two new methods, and replaces perSourceBehaviors with an object.

$3

The sourceunstable event will be fired when the plugin detects a condition that suggests the video player is in the process of changing sources, but that it's too early to know what the new source is or will be.

This is not a guarantee that the source will even change, but it's close - and one of the goals of this project is to continually improve this detection.

$3

The sourcechanged event will be fired once the call stack is cleared after the first of a subset of standard [HTMLMediaElement events][standard-events] is encountered where the currentSrc() returned by the player has changed from the previously cached value.

| previous src | current src | ad state | triggered? |
|:------------:|:-----------:|:--------:|:----------:|
| null | null | :x: | :x: |
| null | foo.mp4 | :x: | :white_check_mark: |
| null | ad.mp4 | :white_check_mark: | :x: |
| foo.mp4 | foo.mp4 | :x: | :x: |
| foo.mp4 | foo.mp4 | :white_check_mark: | :x: |
| foo.mp4 | bar.mp4 | :x: | :white_check_mark: |
| foo.mp4 | bar.mp4 | :white_check_mark: | :x: |
| foo.mp4 | ad.mp4 | :white_check_mark: | :x: |
| ad.mp4 | foo.mp4 | :white_check_mark: | :x: |

#### Extra Event Data

An object with the following properties is passed along with sourcechanged events as the second argument to any listeners:

- from: The source URL _before_ the event.
- to: The source URL _after_ the event (and currently).
- interimEvents: An array of _all_ the events that occurred in the player between the event that triggered the check to the last event that fired before the call stack cleared.

Put another way, the object follows the following schema:

`js
{
from: ,
to: ,
interimEvents: [{
time: ,
event:
}, ...]
}
`

$3

The onPerSrc() method has the same behavior as on() with the crucial exception that it will unbind itself if the listener is ever called with a different source than when it was bound.

Additionally, these listeners will be removed immediately before the plugin triggers a sourcechanged event. This is done because one of the core use-cases is adding new per-source listeners on the sourcechanged event and there is a chance they can double-up otherwise.

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The onePerSrc() method has the same behavior as onPerSrc() except that it can only be called _once_.

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These methods will disable and enable (respectively) the per-source behaviors on this player.

This is useful in more complex use-cases where you might want to manipulate the player state without triggering per-source behaviors. A good example of this might be advertising playback.

#### What happens when per-source behaviors are disabled?

- The sourcechanged event will not be fired even if the source changes.
- Any onPerSrc()/onePerSrc() listeners will not be called.
- Binding new onPerSrc()/onePerSrc() listeners will be prevented.

$3

Use these methods to inspect the current enabled/disabled state of the player as pertains to per-source behaviors. Both return a Boolean.

$3

Exposes the semantic version number of the plugin. This is also exposed on the plugin function (i.e. videojs.getComponent('Player').prototype.perSourceBehaviors`).

License

Apache-2.0. Copyright (c) Brightcove, Inc.

[standard-events]: https://www.w3.org/TR/html5/embedded-content-0.html#mediaevents
[videojs]: http://videojs.com/