Generate PDF on client side

11 02 2009

I just came across this link which is an open source library for generating PDFs on client side using actionscript 3.0. Wow! it is, obviously, a fantastic utility!

Alive PDF

Alive PDF


Flex and ASDocs

30 01 2009

Flex builder offers a very easy way to generate documentation for your actionscript classes API. There are basically 2 steps involved:

– Comment your actionscript class as per ASDoc guidelines. You can refer the instructions in the Flex documentation.

– Use ASDoc external tool from within your Flex builder to generate the documentation. You can do this using commandline as well. However, I found it much more convenient using Flex builder.

Here’s what I did for my project:

Tool used: Flex Builder 3, SDK 3.2.0

1. Add comments to my custom UniConverter class (plz note this is not the complete class) as follows:

	import fl.core.UIComponent;

	* This component class can be used to convert different
	* special characters to unicode characters for a given string.
	public class UniConverter extends UIComponent
		private var _strResult:String;

		* Convert basic latin special characters to unicode for a
		* given string.
		* @param src The source string that contains basic latin
		* special characters which needs to be converted to unicode.
		* @return The source string with basic latin
		* special characters converted to unicode.
		public function basicLatin(src:String):String
			if (src == null)
				throw("Invalid source string.");
				_strResult = src;

				return _strResult;

2. Select Run > External Tools > Open External Tools Dialog

3. Add a program and name it ASDoc_Uni. You can give any name.

4. Location: field — add C:\Program Files\Adobe\Flex Builder 3\sdks\3.2.0\bin\asdoc.exe

5. Working Directory: field — browse to my project folder. The field shows ${workspace_loc:/UniConverter} which points to my working directory.

6. Arguments: field — add the following command

-source-path "C:\Program Files\Adobe\Adobe Flash CS4\Common\Configuration\Component Source\ActionScript 3.0\User Interface"
-doc-classes fl.core.UIComponent 
-exclude-classes fl.core.UIComponent
-main-title "Unicode Converter" 
-window-title "Unicode Converter"

The above command adds 2 source paths for the classes that have been used – my project directory and the current actionscript API. It specifies 2 classes – my custom class and the UIcomponent class which it inherits. Now, I only want my custom class in the documentation and not the flash inbuilt UIComponent class. To exclude the UIComponent class, specify it next to -exclude-classes and also set -exclude-dependencies=true. Finally, I just set the documentation title and the window title as “Unicode Converter”. There’s more you can do, just check the ASDoc documentation.

7. Once through, click Run. A new folder named asdoc-output is created in project folder. Open the folder and launch index.html. There you go, documentation is all set.


Flex ASDoc Tool

Flex ASDoc Tool

Handle XML with namespaces

29 01 2009

Yesterday, I faced an issue while working with an xml file in Flash. I was unable to parse the xml data using the normal E4X syntax such as xml.node1.node2. It would give an error. The only thing different about this particular xml is that it has a lot of namespaces declared in it. After going through the documentation I found out a way to handle this issue. Check the following code:

var xml:XML = <Workbook xmlns:c="urn:schemas-microsoft-com:office:component:spreadsheet" xmlns:html="" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:xsi="" xmlns="urn:schemas-microsoft-com:office:spreadsheet" xmlns:x2="" xmlns:ss="urn:schemas-microsoft-com:office:spreadsheet" xmlns:x="urn:schemas-microsoft-com:office:excel">
	<ss:Worksheet ss:Name="Sheet1">
	<Table ss:StyleID="ta1">
		<Row ss:AutoFitHeight="0" ss:Height="13.4064">
				<Data ss:Type="String">Preview</Data>
				<Data ss:Type="String">unicode</Data>
				<Data ss:Type="String">htmlcode</Data>
				<Data ss:Type="String">htmlalt</Data>
				<Data ss:Type="String">utfcode</Data>
				<Data ss:Type="String">utfalt</Data>

namespace ns1 = "urn:schemas-microsoft-com:office:spreadsheet";
use namespace ns1;

trace(xml..*::Table.Row[0].Cell[0].Data); //Preview

Here, I just declared the default namespace for the above xml. Try this code without the namespace statement and you will get an error. The namespace declared without a prefix is the default namespace for the xml. For this xml the default namespace is xmlns=”urn:schemas-microsoft-com:office:spreadsheet”.

In this case what I’ve done is declared the default namespace in actionscript. And to reference a deeply nested node I’ve used “..*::” instead of a simple ” ..”

Also, in case you want to remove all the namespaces mentioned in the xml, you can try doing something like this:

var arNS:Array = xml.inScopeNamespaces();
for each (var item:Namespace in arNS)

However, do note that this will not remove the default namespace.

Flex vs Silverlight vs AJAX vs JavaFX

15 01 2009

Yesterday, I was having this interesting conversation with a couple of  friends regarding which technology will rule the RIA space in the future. I believe, there’s room for all four of these as per my observations and experience. In fact, all these will have a separate domain and overlap at only few places. For example, AJAX is widely popular for creating community building apps,  portals, mashups, and so on. Flex is used for multimedia rich requirements, for example, interactive maps, photo albums, portfolios, games, product websites, etc. Silverlight is a direct competition here but might have more presence in the Enterprise apps market.

Flex has an advantage of running on the Flash platform which has a very wide reach on the internet and an integrated support from other Adobe products such as Photoshop, Flash, Illustrator, Fireworks, After Effects and some upcoming products – Catalyst, Thermo, Cocomo, and more. These are industry leading tools that help in building visually rich images, animations, and videos. AIR version adds value by having a desktop version of an app that is integrated with the online one.

Silverlight has the benefit of a huge community of .Net developers who will not need to learn anything new from scratch and utilize the huge libraries of .Net components available in the framework. It has a seamless integration between desktop and online version as well. Because of this, building enterprise applications will be the area in which Silverlight might edge over others.

AJAX, ofcourse, has two big advantages which has no competition as of now. These are – no plugin required and SEO enabled. That’s why apps like eBay, Amazon, MySpace, Blogs, and many more will continue to be largely based on AJAX with a few widgets/components built on either of the other three technologies.

JavaFX, is a late entry into this domain, although it all started with a Java product only i.e. Applet. Java enthusiasts will definitely lap onto this. It just remains to be seen what kind of value add JavaFX will bring over others. You never know, since it’s Java, the most reliable internet technology when it comes to providing security to user’s data.

There can, maybe, a scenario where a single app (for example eBay) utilizing all the four technologies for its different features.

So, whatever may happen, it’s the user who will benefit the most with a wide array of technologies to choose from. For developers, it will be important to specialize in one and at least have a good understanding of the rest to provide the best solution to a customer.

Mantra for successful app development

26 12 2008

Just wanted to jot down a few aspects of application development that can ensure success:

1. Version control: Manage your source code using a version control system. It will save you from accidents such as ” omygod!! an important file got deleted”, “damn! my hard disc crashed”, “shucks! client is asking for a previous version which has been updated now”, and more.  you can try MS VSS or TortoiseCVS. Client side TortoiseCVS is free to use.

2. TDD: Apply Test Driven Development so that much of the bug testing and fixing is done in the development phase and the code is relatively bug free. For Flash and Flex development you can use ASUnit or FlexUnit. FlexUnit gives you a very nice Flex based interface which is a nice advantage.

3. OOP and design patterns: Apply relevant OOP concepts and design patterns for ensuring optimized code that is reusable, scalable, and flexible.

4. UML modeling: Always start your project with creating the architecture class diagram. Spend as much time as possible on this. A robust diagram in the beginning will ensure less coding time and also flexibility or scaling issues in the later stages can be handled effectively.

5. Error handling: Incorporate effective error handling for saving your application crash from unexpected bugs while running and also letting the user know what might’ve gone wrong and provide an alternate path.

6. Be friendly with your fellow coders and share a good laugh :-) Okay, that’s a given for any kind of team work.

I’m sure there are lots more but right now I could think of  these as the most important ones from a developer’s perspective.

BitmapData effects

23 12 2008

Recently there was an actionscript competition at The Flash Blog – 25 lines that would impress Einstein. You need to create something innovative using only 25 lines of code. The absolutely fantastic  results were declared on Dec 18. It’s amazing to see what people can do with only 25 lines of code in Flash. Check out the top entries here…

I noticed one common thing being used to create some of these effects is the BitmapData class for manipulating bitmap objects. Here, I will share a very basic example to show what can be done using this object.

1. Create a new file (actionscript 3.0) in Flash CS3 IDE.

2. Change the stage dimensions as 400 x 200 and frame rate as 24 fps.

3. Select frame 1. Copy the following code in code editor:

//import bitmap classes
import flash.display.Bitmap;
import flash.display.BitmapData;

//create a BitmapData object
var myBitmapDataObject:BitmapData = new BitmapData(400, 200, false, 0x00FF0000);

//create a random number which will be used for setting the seed for adding noise to the bitmadata object
var seed:Number = Math.floor(Math.random() * 100);
//set up a channel with a mix of  three main colors - red, blue, green
var channels:uint = BitmapDataChannel.GREEN | BitmapDataChannel.BLUE | BitmapDataChannel.RED
//create a new bitmap with the bitmapdata object
var myBitmap:Bitmap = new Bitmap(myBitmapDataObject);
//use enterframe event for animating the bitmap effect
addEventListener(Event.ENTER_FRAME, updateImage);

var velo:int = 10;
function updateImage(e:Event):void
	if (velo >= 200)
		velo = -Math.abs(velo);
	//add noise with baseX and baseY properties set to var velo which is constantly changing
	myBitmapDataObject.perlinNoise(velo++, velo++, 6, seed, false, true, channels, false, null);

4. Publish the file.

There  you go. You will see a colorful animated cloud being zoomed in and zoomed out.


Bitmap Cloud Effect

Bitmap Cloud Effect

Dividing your Flex app in different SWF files

20 12 2008

I came across a Adobe live docs PDF that I believe is very important for any serious Flex developer. Sooner or later you will be developing an application that will scale up to proportions that might become unmanageable in terms of code, file size, and performance.

Flex provides 2 ways to deal with it – modular approach and sub-applications. Both ways you load and unload separate SWF files into the main application for keeping certain functionality separate and available only when required. Besides some other issues this can also give rise to an issue of having different version of Flex for the loading sub apps and that needs to be taken care of early on.

This PDF details all the considerations that should go into making a decision on which approach to follow for building a large application. A must read for all Flex developers.