Play audio from firefox extension's data directory

Question

I'm making a Firefox extension and I'm failing to play a sound that's located in add-on's data directory.

1. The first thing I've tried was playing it in a content script this way:

   var soundFile = self.options.soundFile;
   (new Audio(soundFile)).play();
   

   where self.options.soundFile is an option that refers to a resource file in data directory. But I meet security restrictions:

   Security Error: Content at http://example.com may not load or link to resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/stackoverflow-reiew-helper/data/complete.oga.
   

2. Then I've found a way to play sounds in main.js script (here: How to play audio in an extension?):

   var data = require('sdk/self').data;
   
   exports.main = function() {
           var {Cc, Ci} = require("chrome");
           var sound = Cc["@mozilla.org/sound;1"].createInstance(Ci.nsISound);
           sound.play(data.url('complete.oga'));
   };
   

   This one fails with the following exception:

   NS_ERROR_XPC_BAD_CONVERT_JS: Could not convert JavaScript argument arg 0 [nsISound.play]
   undefined 8
   Traceback (most recent call last):
     File "resource://gre/modules/NetUtil.jsm", line 140, in null
       aCallback(pipe.inputStream, aStatusCode, aRequest);
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/net/url.js", line 49, in null
       resolve(data);
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 143, in resolve
       while (pending.length) result.then.apply(result, pending.shift())
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 37, in then
       return { then: function then(resolve) { resolve(value) } }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 117, in resolved
       function resolved(value) { deferred.resolve(resolve(value)) }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 143, in resolve
       while (pending.length) result.then.apply(result, pending.shift())
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 37, in then
       return { then: function then(resolve) { resolve(value) } }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 117, in resolved
       function resolved(value) { deferred.resolve(resolve(value)) }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 143, in resolve
       while (pending.length) result.then.apply(result, pending.shift())
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 37, in then
       return { then: function then(resolve) { resolve(value) } }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 117, in resolved
       function resolved(value) { deferred.resolve(resolve(value)) }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 143, in resolve
       while (pending.length) result.then.apply(result, pending.shift())
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 37, in then
       return { then: function then(resolve) { resolve(value) } }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 117, in resolved
       function resolved(value) { deferred.resolve(resolve(value)) }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 143, in resolve
       while (pending.length) result.then.apply(result, pending.shift())
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 37, in then
       return { then: function then(resolve) { resolve(value) } }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 117, in resolved
       function resolved(value) { deferred.resolve(resolve(value)) }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 143, in resolve
       while (pending.length) result.then.apply(result, pending.shift())
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 123, in then
       else result.then(resolved, rejected)
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 37, in then
       return { then: function then(resolve) { resolve(value) } }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 117, in resolved
       function resolved(value) { deferred.resolve(resolve(value)) }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 55, in effort
       try { return f(options) }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 117, in resolved
       function resolved(value) { deferred.resolve(resolve(value)) }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 143, in resolve
       while (pending.length) result.then.apply(result, pending.shift())
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 37, in then
       return { then: function then(resolve) { resolve(value) } }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 117, in resolved
       function resolved(value) { deferred.resolve(resolve(value)) }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/core/promise.js", line 55, in effort
       try { return f(options) }
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/addon/runner.js", line 90, in onLocalizationReady
       run(options);
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/addon-sdk/lib/sdk/addon/runner.js", line 134, in run
       quit: exit
     File "resource://jid0-a02no8rrtu2pbize7g7sszzo0z8-at-jetpack/stackoverflow-reiew-helper/lib/main.js", line 8, in exports.main
       sound.play(data.url('complete.oga'));
   

   If I replace sound.play(...) with sound.beep, I get a nice default system sound. So, there should be something wrong with passing resource path to the function.

If it matters in any way, I'm using online Add-on Builder.

Please suggest a solution of playing a solution of playing extension audio resources.

Answer 1

nsISound.play() takes an nsIURI instance, not a string. You have to create it via nsIIOService.newURI() first:

var uri = Cc["@mozilla.org/network/io-service;1"]
            .getService(Ci.nsIIOService)
            .newURI(data.url('complete.oga'), null, null);
sound.play(uri);

I would recommend against this approach however, nsISound.play() API is pretty much deprecated and IMHO not capable of playing ogg files anyway.

Audio constructor requires access to a proper HTML document. Easiest way to get one in an SDK-based extension is using page-worker module:

require("page-worker").Page({
  contentScript: "new Audio('complete.oga').play()",
  contentURL: data.url("blank.html")
});

Both your sound file and blank.html (an empty HTML file) need to be located in the data/ directory of the extension - note how the audio file is loaded via a relative URL. Right now I don't see a way to avoid having an empty HTML file in the extension, HTML files outside the extension don't have access to extension files and cannot play them.