library – The Page Not Found Blog

JavaScript obfuscators and minifiers do their job well. In fact, some obfuscators have anti-debugging features. However, if you are a legitimate developer building applications against one of these libraries, chances are you’ve gotten an indecipherable error such as “z=null line 14300” and it brings your development efforts to a halt. Error messages like this provide no useful information on what the problem really is, or give any hints on how you might be able solve it. You’ve probably even looked at the jumbled source code in a last ditch attempt to make some sense out of the error. And, whether it’s your own library or a mainstream ones as jQuery or Dojo, it doesn’t matter. The amount of productivity lost because of these errors in probably very large, not to mention the frustration it causes.

I hope the the developers of these obfuscators are reading this…because I have a proposed solution to the problem.

Now, I want to start out by mentioning that I fully understand why obfuscators exist for reasons such as source code protection and decreasing download size. What I propose takes this fully into account, yet makes your library developer friendly in a secure way:

During the obfuscation process create an index file that maps each variable, function and class to a real line number and store this file in a web folder. Then create a small html file that lets you search the index and return the real line number. Provide an option for return the variable, function or class name, too.

The concept is that if there is an error, like the “z=null line 14300” I mentioned above, developers can then at least have some hope of narrowing down the general area of the code where it might be occurring.

The bonus is, if you own an obfuscated commercial library, now your tech support people can also look up the general area where a customer might be having a problem. For security reasons you don’t have to share the index file, But, even then, there isn’t enough information in it to de-compile the library. Now, if I post my error to the forum: What is “z=null line 14300”? Tech support will be able to tell me that I’m missing a custom property on a widget’s HTML DIV element. It’s a win-win situation.

What do you think?

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>

Tag: library

The problem with JavaScript Obfuscators and Minification – Tracking down errors

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