Learning Adobe Flex 3 Series - Part 1
Flex: Comparing Flash, Flex, Flash Player, and AIR
Accessing HTML Querystrings in AS3
You can pass variables to SWF files in the object/embed code used to display a SWF in HTML. You can do this two ways, one using URL variables (query string) at the end of the SWF path, or through the FlashVars property.
HTML Code:
<!-- URL Variables --> <object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://fpdownload.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,0,0" width="640" height="500" align="middle"> <param name="allowScriptAccess" value="sameDomain" /> <param name="movie" value="flashMovie.swf?myVar=1" /> <param name="quality" value="high" /> <param name="bgcolor" value="#EFF7F6" /> <embed src="flashMovie.swf?myVar=1" quality="high" bgcolor="#EFF7F6" width="640" height="500" align="middle" allowScriptAccess="sameDomain" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" /> </object>
HTML Code:
<!-- FlashVars --> <object classid="clsid:d27cdb6e-ae6d-11cf-96b8-444553540000" codebase="http://fpdownload.macromedia.com/pub/shockwave/cabs/flash/swflash.cab#version=9,0,0,0" width="550" height="400" align="middle"> <param name="allowScriptAccess" value="sameDomain" /> <param name="movie" value="flashMovie.swf" /> <param name="quality" value="high" /> <param name="bgcolor" value="#FFFFFF" /> <param name="FlashVars" value="myVar=1" /> <embed src="flashMovie.swf" FlashVars="myVar=1" quality="high" bgcolor="#FFFFFF" width="550" height="400" align="middle" allowScriptAccess="sameDomain" type="application/x-shockwave-flash" pluginspage="http://www.macromedia.com/go/getflashplayer" /> </object>
In ActionScript 2, these variables were simply defined as variables in _root. This has changed for ActionScript 3. Now these variables are accessible in a parameters object located in the root loaderInfo object.
Given the HTML embed code above, you would access the myVar property using:
ActionScript Code:
root.loaderInfo.parameters.myVar;
How to get a list of child objects that are inside another object
Here is an easy way to get a list of child objects from inside another object.
for(x=0; x < my_mc.numChildren; x++){
trace("Type:"+my_mc.getChildAt(x)+"Name:"+my_mc.getChildAt(x).name);
}
Using the MouseWheel to Scroll in AS3
Here is a nice little chunk of code that I wrote to help you enable the MouseWheel in your Flash AS3 files.
// Import MouseEvent
import flash.events.MouseEvent;
// Create MouseWheel Event
public function handleMouseWheel(event:MouseEvent){
trace(event.delta);
}
// Add MouseWheel Listener
addEventListener(MouseEvent.MOUSE_WHEEL,handleMouseWheel);
This will trace the movement from the MouseWheel and that value can be used in your Flash movie however you would like. Enjoy!
UPDATE: It has come to my attention that Firefox doesn’t always like this. Here is how you work around it. (Thanks Ben)
In JS…
function mozScroll(e)
{
if(cork.PercentLoaded() == 100)
if(cork.FirefoxMouseWheel)
cork.FirefoxMouseWheel(0, e.detail);
}
if(window.addEventListener)
{
window.addEventListener('DOMMouseScroll', mozScroll, false);
}
…and in AS3…
ExternalInterface.addCallback("FirefoxMouseWheel", ZoomInOut);
...
public function ZoomInOut(event:* = null, mozDeltaOverride:* = null):void {...}