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Firefox 4 not showing newly installed plugins in navigator.plugins array

  • 5 cavab
  • 11 have this problem
  • 4 views
  • Last reply by Xman1234

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In Firefox 4 I am trying to detect with javascript if a certain plugin is installed by looking for it in the navigator.plugins array. (https://developer.mozilla.org/en/DOM/window.navigator.plugins)

It seems that newly installed plugins in Firefox 4 do not show up in that array.

I have restarted Firefox, and they show up in Firefox's Add-ons Manager but not in the navigator.plugins array.

I know Firebug works because I used it to show me the contents of of window.plugins.

(Also, you can even see that your script didn't pick up Firebug when you automatically retrieved my list of plugins to populate the "Installed Plugins" field in this post.)

In Firefox 4 I am trying to detect with javascript if a certain plugin is installed by looking for it in the navigator.plugins array. (https://developer.mozilla.org/en/DOM/window.navigator.plugins) It seems that newly installed plugins in Firefox 4 do not show up in that array. I have restarted Firefox, and they show up in Firefox's Add-ons Manager but not in the navigator.plugins array. I know Firebug works because I used it to show me the contents of of window.plugins. (Also, you can even see that your script didn't pick up Firebug when you automatically retrieved my list of plugins to populate the "Installed Plugins" field in this post.)

Chosen solution

I think that plugins installed via an XPI file like an extension should still appear on the about:plugins page. I'm on Linux and that is how the Silverlight (Moonlight) plugin installs.

A good place to ask questions and advice about web development is at the mozillaZine Web Development/Standards Evangelism forum.
The helpers at that forum are more knowledgeable about web development issues.
You need to register at the mozillaZine forum site in order to post at that forum.

See http://forums.mozillazine.org/viewforum.php?f=25

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All Replies (5)

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Does it help if you refresh that list by opening the about:plugins page?

javascript:navigator.plugins.refresh(true);

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Thanks for the quick response.

I think I have found the difference. The 'plugin' I was referring to is actually listed as an Add-On in about:addons and it is not listed in about:plugins.

Could it be that in 3.5 it was showing up for me in the plugins[] array because I had copied the .dll into Firefox's plugins directory. But this latest time I installed it using the xpi.

Or is it that in Firefox 3.5 our plugin is actually listed as a Plugin, and now in Firefox 4.0 it is listed as an Addon?

Is there an official way to use javascript to determine if a specific "Addon" is installed?

Modified by tones411

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If there is not a way to detect if an addon is installed, is there a way for us to program our plugin so it shows up in the about:plugins page and in the navigator.plugins array?

Modified by tones411

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Seçilmiş Həll

I think that plugins installed via an XPI file like an extension should still appear on the about:plugins page. I'm on Linux and that is how the Silverlight (Moonlight) plugin installs.

A good place to ask questions and advice about web development is at the mozillaZine Web Development/Standards Evangelism forum.
The helpers at that forum are more knowledgeable about web development issues.
You need to register at the mozillaZine forum site in order to post at that forum.

See http://forums.mozillazine.org/viewforum.php?f=25

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tones411 were you able to get this done?