Bride of Flashenstein

PS Woods

July 5, 2000

JavaScript isn't going to go away just yet; and Flash becomes a more prominent part of the web landscape every day, whether you think of it as a weed or a flower. Put them together and BAM! - you got your chocolate in your peanut butter. Flash developers are already doing lots of cool stuff with Flash/JavaScript, but you have to do a little digging to get started. Well, here is a good place to break ground...

Using Flash with JavaScript (by Example)

This is a quick-and-dirty introduction to Flash with JavaScript. The reader should already know the basics of both JavaScript and Flash. Basically we are going to walk through a script and Flash movie to get an idea of how to bridge the two.

First download the Flashenstein.zip; unzip it and look at it to get an idea of what we are doing. The concept is that we are running a "personalized" news site using a cookie to store the user's preferences. (NOTE: This isn't the most brilliant scheme for personalized content. This example is devised to get some ideas going and do something a little more practical with Flash. Don't spend too much time looking at the Flash file - it is quick and dirty to say the least).

I usually oppose printing things on paper with religious zeal, but for a big hunk of sloppy code I like to print it from my favorite HTML editor (1st Page 2000), block off the (commented) functions with a hi-lighter, and write their names in with a ball point pen so I can quickly follow the structure.

Let's read down the page just like the browser does. First you have this:

	//user configure variables

	var retiresAt = new Date("December 31, 2050");

	var cookieName="WDVL_FlashCookie";

	//init global

	var acceptsCookies = false;

Straightforward. retiresAt will become the GMT cookie expiration and the cookieName will be the name of the cookie, (duh). We initialize a variable that we will need later.

Everything else is a function until you get to the body tag:

<body onLoad="flashReadCookie();">

      <object CLASSID="clsid:D27CDB6E-AE6D-11cf-96B8-444553540000" 

      codebase="http://download.macromedia.com/pub/
      shockwave/cabs/flash/swflash.cab#version=4,0,2,0"
	  
      ID="flashfile" WIDTH="600" 
      HEIGHT="450">
	  
      <param name="movie" value="cookie_write.swf">
	  
      <param name="play" value="false">
	  
      <param name="quality" value="high">
	  
      <embed NAME="flashfile" SRC="cookie_write.swf" 
      WIDTH="400" HEIGHT="300" PLAY="false" SWLIVECONNECT="true" 
      QUALITY="high"
	  
      pluginspage="http://www.macromedia.com/shockwave/download/
      index.cgi?P1_Prod_Version=ShockwaveFlash">
	  
      </embed> 
	  
      </object> 
	  
      </body>

The first thing to notice here is that we don't start executing any script until everything is loaded (onLoad...). The other thing is the name "flashfile". This is the name of the Flash Player object we create with the OBJECT and EMBED tags, (document.flashfile in our example).You must name it using the ID attribute in the OBJECT tag and the NAME attribute in the EMBED tag. This name can be anything you want - and needn't correspond to the name of your .swf file.

Bride of Flashenstein

Using Flash with JavaScript (by Example)

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