| Passing variables to flash
As part of my site deign I was after a method in which I could have a
reusable banner. This banner was going to be a flash program and would
be cached for every page. I wanted to pass a variable to the flash program,
and that would be the title for that page.
There are several methods of passing variables to a flash program. The
first method that I used, passed the variables via the HTML tag value.
Below is an extract of the code that I use for the navigation bar:
<OBJECT classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
codebase="http://download.macromedia.com/pub/shockwave/ cabs/flash/swflash.cab#version=5,0,0,0"
WIDTH=155 HEIGHT=450>
<PARAM NAME=movie VALUE="/nav_bar_mncom.swf?first_menu=Web Design">
<PARAM NAME=quality VALUE=best>
<PARAM NAME=salign VALUE=T>
<PARAM NAME=bgcolor VALUE=#000000>
<EMBED src="/nav_bar_mncom.swf" quality=best salign=T bgcolor=#000000
WIDTH=140 HEIGHT=450 TYPE="application/x-shockwave-flash" PLUGINSPAGE="http://www.macromedia.com/
shockwave/download/index.cgi?P1_Prod_Version=ShockwaveFlash">
</EMBED>
</OBJECT>
The code in yellow is what I added to get the variable passed to my flash
program. Inside my flash program I use the variable "first_menu"
to indicate which menu has to be displayed when the page is loaded. This
works well, but for one problem. Passing a variable in this manner causes
the browser to cache each variation of the variable. In the above example,
I would have a "nav_bar_mncom.swf?first_menu=Web%20Design" variable
in my cache. For the navigation bar there are only a few variations so
it was not a problem. But with the banner, every page had a different
banner, and therefore the browser ended caching every variation. This
partly defeated the purpose of having a reusable banner. So another method
was needed which kept the same swf in cache. The method used was the Javascript
setVariable method.
<script language = "JavaScript">
<!--
function PassFlash(){
window.document.mndbanner.SetVariable("banner", "Flash
Tutorial");
}
//-->
</script>
<body onLoad="PassFlash()" >
<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
codebase="http://download.macromedia.com/pub/shockwave/ cabs/flash/swflash.cab#version=5,0,0,0"
id=mndbanner width=575 height=100
align="middle">
<param name=movie value="/mnd_banner.swf">
<param name=quality value=best>
<param name=salign value=T>
<param name=bgcolor value=#000000>
<embed src="/mnd_banner.swf" quality=best salign=T bgcolor=#000000
width=575 height=100 NAME=mndbanner swLiveConnect=true type="application/x-shockwave-flash"
pluginspage="http://www.macromedia.com/ shockwave/download/index.cgi?P1_Prod_Version=ShockwaveFlash"
align="middle">
</embed>
</object>
Extra bits have to be added in the code that loads the swf plugin. They
are the id=mndbanner in the codebase tag, the NAME=mndbanner and swLiveConnect=true
in the embed tag. The movie name ( name of the swf file), in this case
mndbanner has to be the same as shown.
One final piece of code that has to be included is the onLoad="PassFlash()"
inside the body tag. This tells the browser to execute the javascript
function PassFlash() when the page is loaded. Keep in mind that the variable
will not be passed till the page is fully loaded. Another option to load
the banner variable is to included a call of the PassFlash() function
just after the object is defined.
<script language = "JavaScript">
<!--
function PassFlash(){
window.document.mndbanner.SetVariable("banner", "Flash
Tutorial");
}
//-->
</script>
<body>
<object classid="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000"
codebase="http://download.macromedia.com/pub/shockwave/ cabs/flash/swflash.cab#version=5,0,0,0"
id=mndbanner width=575 height=100
align="middle">
<param name=movie value="/mnd_banner.swf">
<param name=quality value=best>
<param name=salign value=T>
<param name=bgcolor value=#000000>
<embed src="/mnd_banner.swf" quality=best salign=T bgcolor=#000000
width=575 height=100 NAME=mndbanner swLiveConnect=true type="application/x-shockwave-flash"
pluginspage="http://www.macromedia.com/ shockwave/download/index.cgi?P1_Prod_Version=ShockwaveFlash"
align="middle">
</embed>
</object>
<script language = "JavaScript">
<!--
PassFlash();
//-->
</script> |
