从 firefox 扩展的数据目录播放音频

Question

我正在制作一个 Firefox 扩展程序，但无法播放位于附加组件 data 目录中的声音。

1. 我尝试的第一件事是以这种方式在内容脚本中播放它：

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

   其中self.options.soundFile 是一个选项，它引用data 目录中的资源文件。但我符合安全限制：

   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. 然后我找到了一种在main.js 脚​​本中播放声音的方法（这里：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'));
   };
   

   这个失败，但有以下异常：

   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'));
   

   如果我用sound.beep 替换sound.play(...)，我会得到一个很好的默认系统声音。因此，将资源路径传递给函数应该有问题。

如果有任何问题，我正在使用在线插件生成器。

请提出一个播放扩展音频资源的解决方案。

Answer 1

nsISound.play() 采用 nsIURI 实例，而不是字符串。您必须先通过nsIIOService.newURI() 创建它：

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

但我建议不要使用这种方法，nsISound.play() API 是 pretty much deprecated，恕我直言，无论如何都无法播放 ogg 文件。

Audio 构造函数需要访问正确的 HTML 文档。在基于 SDK 的扩展中获取一个的最简单方法是使用 page-worker module：

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

您的声音文件和blank.html（一个空的 HTML 文件）都需要位于扩展程序的 data/ 目录中 - 请注意音频文件是如何通过相对 URL 加载的。现在我没有办法避免在扩展中包含一个空的 HTML 文件，扩展之外的 HTML 文件无法访问扩展文件并且无法播放它们。