actionscript – Page 4 – The Page Not Found Blog

URLStream, Adobe AIR and FLEX security permission issues on Windows 7

I had a particularly vexing problem that took nearly a half a day to dig to the bottom of. I was successfully able to connect to a streaming API using Adobe’s URLStream class, and I could see the passing of packets back-and-forth between the client app and the remote server using WireShark. So, there was definitely a valid connection and hand-shaking happening in the background. And, another key piece to the puzzle was the app ran just fine as a Flex app using the default bin-debug run-time settings. But, other than that running it as an AIR app or a Flex app from IIS, I simply couldn’t get any of the URLStream event listeners to acknowledge any type of connection whatsoever.

I knew this was a permissions issue, but finding documentation on AIR and Flash runtime permissions is, well, not easy. So, after quite a few searches on the internet and many dead-ends, there buried deep in some ancient scrolls of Adobe documentation were a few articles that provided the key to finally unlock the treasure chest.

You may have never heard about it before, but there is a User Flash Player Trust directory that typically contains at least one configuration file. And, in those files you can specifically grant application access to a particularly directory. In theory, there is also a Global Flash Player Trust directory. I originally thought I made the changes to that, but actually I never was able to locate it, and I ran out of time anyway. So, if someone knows where that is on Windows 7 please let me know.

Solution:

I added the pathname to the AIR executable installation directory to the air.1.0.trust.cfg file and bingo the application worked as expected.

The file typically resides in a path that looks like this: C:\Users\<username>\AppData\Roaming\Macromedia\Flash Player\#Security\FlashPlayerTrust

And, I add the following line to the file: C:\Program Files (x86)\BasicStreams.

References:

[Flash Player] Administrator Controls

[Flash Player] User Control document

Adobe Online Doc – Restricting Network APIs

Using FlashBuilder and Ant to Build SWCs with ASDoc Comments (on Windows 7)

It’s always an adventure when you try to use Ant to include your ASDoc comments into an Adobe Flex SWC library. I am completely baffled that Adobe can’t make this an automated step in Flash Builder, because it typically takes a alot of time to make things work correctly the “manual” way. So, I’m adding this blog post to the many already out there in hopes that my work can also help someone else.

I started off with a script that used to work on my old 32-bit laptop, but my new laptop is 64-bit. I kept getting Java Heap errors and I tried everything under the sun including changing FlashBuilder.ini and jvm.config to bump up the max heap size (-Xmx1024m). Nothing would work. What finally fixed this was adding the following line in my compc and asdoc sections of my build.xml file. If I made my settings any larger Flash Builder would throw an error. At some point I want to know why that is:

<jvmarg value="-Xmx1024m"/>

Here’s a few other tips-n-tricks:

A lot of the blog posts I read were written for Mac’s…which I don’t have, so all the directory slashes were going the wrong direction.
You need to install the Ant tools into FlashBuilder first. To do that go to Help > Install New Software and use this link: https://download.eclipse.org/releases/galileo
When that loads its packages, look under Programming Languages for the option called Eclipse Development Tools and install that.
Create a new Flex Library Project and drop in the actionscript class you want to convert.
Create a file called build.xml and place it in the root directory of your project.
Right click on the build.xml file and choose Run As > Ant Build.
If you have errors, use echo statements to try and find out what’s going on.
You absolutely must have a <taskdef> reference that points to flexTasks.jar.
I also needed to include another class library into the build. You can see how I did that under the asdoc section using this pattern:

<compiler.source-path path-element="${basedir}\src"/>
<arg value="-external-library-path=${basedir}\bin\agslib-2.2-2010-12-08.swc"/>

References:

Adobe – Use the ASDoc Tool
Gaurev’s Blog – Creating Swc Files with ASDoc Comments


<?xml version="1.0"?>
<project name="mapsaverlib-1.0" default="main" basedir=".">

	<property name="FLEX_HOME" value="C:\Program Files (x86)\Adobe\Adobe Flash Builder 4\sdks\4.0.0"/>
	<taskdef resource="flexTasks.tasks"
		classpath="C:\Program Files (x86)\Adobe\Adobe Flash Builder 4\sdks\4.0.0\ant\lib\flexTasks.jar" />

	<echo message="Flex Home ${FLEX_HOME} "/>

	<!--<target name="main" depends="clean, compile, doc" description="Clean build of <filename>.swc">-->
	<target name="main" depends="compile, doc" description="Clean build of mapserverlib-1.0.swc" />

	<echo message="clean"/>

	<target name="clean" depends="clean-temp-docs">
		<delete failonerror="false">
			<fileset dir="${basedir}\bin">
				<include name="${ant.project.name}.swc"/>
			</fileset>
		</delete>
	</target>

	<target name="compile" depends="" description="Compile SWC">

		<echo message="Compiling ${ant.project.name}.swc"/>

		<compc fork="true" output="${basedir}\bin\${ant.project.name}.swc">
		    <source-path path-element="${basedir}\src"/>
		    <include-sources dir="${basedir}\src" includes="**\*.as **\*.mxml"/>
			<compiler.include-libraries dir="${basedir}\bin\" append="true">
				<include name="agslib-2.2-2010-12-08.swc" />
			</compiler.include-libraries>
			<jvmarg value="-Xmx1024m"/>
		</compc>

	</target>

	<target name="doc" depends="clean-temp-docs, compile"
		description="Updates SWC with ASDoc XML">
		<echo message="Compiling ASDoc for ${ant.project.name}.swc"/>

		<!-- Call asdoc to generate dita xml files -->
		<asdoc output="${basedir}\tempDoc" lenient="true"
			failonerror="true" keep-xml="true" skip-xsl="true" fork="true">
		    <compiler.source-path path-element="${basedir}\src"/>
			<arg value="-external-library-path=${basedir}\bin\agslib-2.2-2010-12-08.swc"/>
			<doc-sources path-element="${basedir}\src"/>
			<jvmarg value="-Xmx1024m"/>
		</asdoc>

		<!-- updates swc with asdoc xml -->
		<zip destfile="${basedir}\bin\${ant.project.name}.swc" update="true">
		    <zipfileset dir="${basedir}\tempDoc\tempdita" prefix="docs">
			    <include name="*.*"/>
				<exclude name="ASDoc_Config.xml"/>
				<exclude name="overviews.xml"/>
		    </zipfileset>
		</zip>
	</target>

	<target name="clean-temp-docs">
		<delete dir="${basedir}\tempDoc" failonerror="false" includeEmptyDirs="true"/>
	</target>

</project>

Best Practices for ActionScript Event Listeners

I see a lot of incorrect instantiation of event listeners, and I’ve also done it wrong quite a few times myself, especially when coding really fast. Doing it right is easy and the following four steps could save you a ton of debugging time later.

Step 1: First, create the object. In this case I’m creating a Timer object using the ActionScript flash.utils.Timer Class:

var myTimer:Timer = new Timer(1000);

Step 2: Second, always add your event listeners before executing any of the objects methods. And always, always attach the event listener to an object. Simply calling an addEventListener without attaching it to an object means the listener will receive any events broadcast for that type of event. This can become a nightmare in projects that may have dozens or even hundreds of event listeners running and you have to debug a problem.

//myTimer is the object to which we will attach the listener.
//timer is the type of listener we want to observe.
//And, timerHandler the function to call when the event occurs.
myTimer.addEventListener(“timer”,timerHandler);

Step 3: Third, now you can call the objects method. I’m going to call the start() method which will kick off the Timer:

myTimer.start();

Step 4: Lastly, when you are done with an object, always remove the event listener. Leaving event listeners active when they aren’t needed can cause memory leaks. If an object is not removed, it is still registered and it will remain in memory. By removing the event listener, you’ll allow the garbage collector to eventually deallocate it from memory.

    myTimer.removeEventListener(“timer”,timerHandler);

Why do things in this order? If you add your event listeners after calling a method, such as start(), you can potentially miss an event that occurs right before the event listener is created. By only calling methods after event listeners are created you eliminate the possibility of missing something and banging your head against the wall while trying to debug it under a heavy deadline.

Here’s a complete Flex 4 sample app that you can play with to try it out:

<?xml version="1.0" encoding="utf-8"?>
<s:Application xmlns:fx="https://ns.adobe.com/mxml/2009"
    xmlns:s="library://ns.adobe.com/flex/spark"
    xmlns:mx="library://ns.adobe.com/flex/mx">
 <fx:Script>
     <![CDATA[   

       private var myTimer:Timer;

       public function timerHandler(event:TimerEvent):void
       {
          var date:Date = new Date();
          textArea1.text = date.hours.toString()+
             ":"+date.minutes.toString()+
             ":"+date.seconds.toString()+
             ":"+date.milliseconds.toString();
       }   

       protected function start_clickHandler(event:MouseEvent):void
       {
           myTimer = new Timer(1000);
           myTimer.addEventListener("timer", timerHandler);
           myTimer.start();
       }

       protected function stop_clickHandler(event:MouseEvent):void
       {
           myTimer.stop(); 
           myTimer.removeEventListener("timer", timerHandler);
       }
  ]]>
 </fx:Script>

 <s:TextArea id="textArea1" x="15" y="70" width="270" height="20"/>
 <s:Button x="15" y="28" label="Start" click="start_clickHandler(event)"/>
 <s:Button x="103" y="28" label="Stop" click="stop_clickHandler(event)"/>
</s:Application>