content/symbiont

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Don't use these techniques to develop new add-ons. Use WebExtensions instead.

If you maintain an add-on which uses the techniques described here, consider migrating it to use WebExtensions instead.

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Unstable

Used by SDK modules that can load web content and attach content scripts to it.

Usage

A Symbiont loads the specified contentURL and content scripts into a frame, and sets up an asynchronous channel between the content scripts and the add-on code, enabling them to exchange messages using the port or postMessage APIs. You map optionally pass a frame into the Symbiont's constructor: if you don't, then a new hidden frame will be created to host the content.

This trait is composed from the Loader and Worker traits. It inherits functions to load and configure content scripts from the Loader, and functions to exchange messages between content scripts and the main add-on code from the Worker.

var { Symbiont } = require('sdk/content/content');
var Thing = Symbiont.resolve({ constructor: '_init' }).compose({
  constructor: function Thing(options) {
    // `getMyFrame` returns the host application frame in which
    // the page is loaded.
    this._frame = getMyFrame();
    this._init(options)
  }
});

See the panel module for a real-world example of usage of this module.

Globals

Constructors

Symbiont(options)

Creates a content symbiont.

Parameters

options : object
Optional options:

Name Type  
frame object

The host application frame in which the page is loaded. If frame is not provided hidden one will be created.

contentScriptWhen string

When to load the content scripts. This may take one of the following values:

  • "start": load content scripts immediately after the document element for the page is inserted into the DOM, but before the DOM content itself has been loaded
  • "ready": load content scripts once DOM content has been loaded, corresponding to the DOMContentLoaded event
  • "end": load content scripts once all the content (DOM, JS, CSS, images) for the page has been loaded, at the time the window.onload event fires

This property is optional and defaults to "end".

contentScriptOptions object

Read-only value exposed to content scripts under self.options property.

Any kind of jsonable value (object, array, string, etc.) can be used here. Optional.

allow object

Permissions for the content, with the following keys:

script boolean

Whether or not to execute script in the content. Defaults to true. Optional. Optional.

Symbiont

Symbiont is composed from the Worker trait, therefore instances of Symbiont and their descendants expose all the public properties exposed by Worker along with additional public properties that are listed below:

Properties

contentScriptFile

The local file URLs of content scripts to load. Content scripts specified by this property are loaded before those specified by the contentScript property.

contentScript

The texts of content scripts to load. Content scripts specified by this property are loaded after those specified by the contentScriptFile property.

contentScriptWhen

When to load the content scripts. This may have one of the following values:

  • "start": load content scripts immediately after the document element for the page is inserted into the DOM, but before the DOM content itself has been loaded
  • "ready": load content scripts once DOM content has been loaded, corresponding to the DOMContentLoaded event
  • "end": load content scripts once all the content (DOM, JS, CSS, images) for the page has been loaded, at the time the window.onload event fires

contentScriptOptions

Read-only value exposed to content scripts under self.options property.

Any kind of jsonable value (object, array, string, etc.) can be used here. Optional.

contentURL

The URL of the content loaded.

allow

Permissions for the content, with a single boolean key called script which defaults to true and indicates whether or not to execute scripts in the content.

Document Tags and Contributors

 Contributors to this page: wbamberg
 Last updated by: wbamberg,