Passing flashVars with Flash 10 in IE

I've spent the last two days debugging a weird issue involving https, IE and Flash.

In the end, I boiled the issue down to IE and Flash 10, https wasn't involved (in fact, that was a different issue).

Markup hell

It is known that to have a real crossbrowser markup to embed Flash we need an IE specific version and a non-IE one.

What I didn't know was that flashvars needed to be passed in two different formats between Flash player 10 and Flash player 11.

11 expect the classic flashvars parameter while 10 expect them to be passed as simili GET parameters to the movie url.

Final HTML markup

In the end, here is the PHP code I use to generate my SWF markup:

sprintf(
  '<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" width="%1$s" height="%2$s" id="%3$s">
    <param name="movie" value="%4$s?%6$s" />
    %5$s
    <!--[if !IE]>-->
      <object type="application/x-shockwave-flash" data="%4$s" width="%1$s" height="%2$s">
      %5$s
    <!--<![endif]-->
    %7$s
    <!--[if !IE]>--></object><!--<![endif]-->
  </object>
',
$width, $height, $id, $url, $params, $flashVars, $alternateContent);

Where:

• $width and $height are the size (in pixel) of your movie
• $id is the html/css id of the main object element (as used in swfObject.getObjectById)
• $url is the url address of your swf file
• $params is a string containing all the <param name="name" value="value" /> that you want to pass. Usually it will contain the wmode, allowfullscreen, allowscriptaccess and flashvars keys.
• $flashVars is a duplicate of the flashVars key of $params and should contain a string in the form foo=bar&baz=nyan to be passed to the swf in Flash 10
• $alternateContent is the html text to be displayed when Flash is not installed in the browse

I hope that this markup will help you, because I spent a damn long time testing all that stuff, jungling between VM and IE instances.