Using RSL’s - Runtime Shared Libraries
Chase Brammer

ABOUT ME
CURRENTLY Developer at Rain Interactive.
Developing for Flex since 2006
Developing for Flash since 2000
Working towards a masters in Information Systems Management at Brigham Young University (BYU)
Website: http://chasebrammer.com
Email: cbrammer@gmail.com
Twitter: chaseb
All of my contact information is listed on my business card, come get one
(I have a big box I will never go through unless you do)

ABOUT ME

RIA DEVELOPMENT

ABOUT RAIN
mediarain.com
FranklinCovey, NuSkin, Novell, NextPage, HP, MyFamily.com, DataMark, MusicRain, Omniture

RAIN
What started it all

WHAT YOU WILL SEE IN THE NEXT HOUR
If you decide to walk out now, it’s OK. Really.
THE GOOD AND BAD OF RSLs
TERMS
USE CASES
Using the Flex Framework as an RSL to speed up load time
Creating your own RSL
Using an unsigned (non-Adobe) RSL
Using an cross-domain unsigned RSL
Optimizing your RSL
Collaborative work with RSL’s
Implementing RSL with a build process (ANT)
WHAT YOU WILL NOT SEE IN THE NEXT HOUR Specific details are of the actual Flex Framework itself, stump
the presenter with the most outlandish use case you can come up with, or super in depth details of the RSL
(This is a 200 level course after all)

THE GOOD AND THE BAD AND THE UGLY
BUT REALLY WHY USING RSLs ROCK
ADVANTAGES
Reduce file size (faster download)
Library Caching
Code reuse
Faster compile time
Single Point of Distribution/Update
Collaborative and Community Work
DISADVANTAGES
Cross domain issues (crossdomain.xml)
Can't create signed RSL's
Debugging
Quick editing
Must download the whole RSL, doesn’t trim unused classes

THE GOOD AND THE BAD AND THE UGLY
BECAUSE SIZE MATTERS
Flex with All Framework Components
Flex with Button, ComboBox,
and TabNavigator
Flex with Button
Example taken from Ted Patrick’s announcement on RSL’s

THE GOOD AND THE BAD AND THE UGLY
BECAUSE SIZE MATTERS
Flex with Button
Flex with Button, ComboBox, and TabNavigator
Flex with All Framework Components
Example taken from Ted Patrick’s announcement on RSL’s

TERMS
Because jargon is confusing
RSL Runtime Shared Library
SIGNED RSL Adobe published RSLs (framework, datavis, rpc)
UNSIGNED RSL The RSL for the rest of us
SWZ An Adobe Signed RSL only for RSLs such as data visualization, Remoting, and the Flex Framework
SWC A zip that contains compiled Flash or Flex project that is not a standalone project. Typically a Flex
Library project or a collection of assets exported from Flash
LIBRARY.SWF One of two files that are included in a SWC that hold the assets of the export (classes, modules,
etc...)
CATALOGUE.XML The second file in a SWC that holds the structure and relationships of all the assets
COMPC The Component Compiler, a command line build utility used to create RSLs
BROWSER CACHE Your browsers of choice cache, not to be confused with the Flash Player Cache
FLASH CACHE The Flash Player’s internal cache that is used to store signed RSLs
ANT Automated command line build utility used to compile flex projects

WHAT IS AN RSL
No, it isn’t the soccer team Real Salt Lake
PURPOSE Why spent time using an RSL
To quickly reduce your application’s file size.
Code once, use in many places
HOW DOES IT DO THAT? Kung Fu. As in Neo type of Kung Fu.
Separates the large core of flex and lets your app go faster (like on Star Trek when they launch their core)
If possible loads the RSL from the Flash Cache (signed RSLs only)
If possible loads the RSL from the browser cache (unsigned RSLs only)
DEVELOPMENT Loads into your project just as if it were a local file, only you can’t edit it

FLEX CORE RSLS
Use case #1: How to speed up your application’s load time
Use case Your app is big. Too big. You need it smaller and faster.
Solution Separate your Flex Framework (or Data Visualization/Remoting) from your compiled swf so that
your project loads like greased lightning.

FLEX CORE RSLS
How to do it
Let me show you.... but just for later reference
Right click your project
Select Project Properties
Select ‘Flex Build Path’
Select the ‘Library Path’ tab
Change the Framework linkage to RSL
Be sure to add “use-network=false” in your compiler
settings to avoid the nasty Error #2148 (Sandbox error)

FLEX CORE RSLS
Look at what we did!
Wow We just reduced our file size by 500k with 8 clicks (or so)
What are those extra files?
You will see two extra files in your release directory after you enable the RSL
framework_3.3.0.XXXX.swf
framework_3.3.0.XXXX.swz
These two files are important. In case the end user doesn’t have the framework version you are using
cached, then they will download it from you! If these two files aren’t there... you will have some headache.

FLEX CORE RSLS
Testing our deployment paths
Clear our cache - IMPORTANT
The framework RSLs are not stored in the browser cache. They are in fact stored is a secret little place that
rarely ever gets seen. The Flash Cache. Only signed RSLs can be included in the flash cache, and if you
don’t know about it existence, it will make debugging a living hell for you.
http://www.macromedia.com/support/documentation/en/flashplayer/help/settings_manager03.html

FLEX CORE RSLS
Testing and changing our RSL deployment path
Testing
The best way to test if your RSL’s are loading in right (and not just loading in from your cache) is to clear
your flash cache, and then move your local framework files (framework_x.x.xxxx.swf/swz) and see if you get
an error.
If you get an error great! That means you have something to work with. Move your files back and make sure
that everything works now.
Changed deployment path
Edit the RSL path, via selecting the RSL url and clicking edit

CREATING YOUR OWN RSL
Use Case #2
Use Case
You have a project that has a core set of components, libraries, or utilities that are pretty much stable and
you don’t want to force the users to re-download all of that every time you release a new build.
Solution
Create a Runtime Shared Library.

CREATING YOUR OWN RSL
Creating a Flex Library
We could do all that we are going to do by using command line compilers (mxmlc/compc), but lets use the
Flex Builder IDE for simplicity
Create a project
Select files you want to include
Thats it!
Now, lets look and see how to use your own, unsigned RSL

USING A CUSTOM RSL
Use Case #3
Use Case
You, a friend, a co-worker, or some dude in India just gave you a SWC, and you want to use it as an RSL
Solution
Import it it into your project, and make it an RSL

USING A CUSTOM RSL
Using your own RSL
Add the SWC to your project
Copy over your compiled SWC in to your libs folder
Right click your project and edit your Library Paths in your
project preferences to add your SWC

USING A CUSTOM RSL
Making your SWC into an RSL
A picture says a thousand words, editing your RSL path

CROSS-DOMAIN RSL
Use case #4: Using a Cross-Domain RSL
Use case Your company has a common set of components, libraries, or assets that you want to share across
multiple projects
Solution Create a Cross-Domain RSL

CROSS-DOMAIN RSL
Too fast, lets digest some of this
TO USE A CROSS-DOMAIN RSL you must have digest enabled
DIGEST A SHA-256 hash that acts as a checksum for your RSL.
WHAT DOES IT LOOK LIKE?
<digests>
<digest type=\"SHA-256\" signed=\"false\"
value=\"839c300d3805a839f4731a23169b8551d16ec167ad184eb6dad4b9cc58597d79\" />
</digests>
HOW TO ENABLE IT
-compute-digest=false
<compute-digest>true</compute-digest>

CROSS-DOMAIN RSL
Use case #4: Using a Cross-Domain RSL
HOW TO INCLUDE A CROSS-DOMAIN RSL
1) Open project properties
2) Select Flex Build Path
3) Select the Library Tab
4) Click “Add a SWC”
5) Add your SWC
6) Open your SWC node
5) Double click on Link Type
6) Change the link type to RSL
7) Change Verification to Digests
8) Make sure your SWF and SWC are uploaded
9) Enter your RSL URL, and Policy File URL

OPTIMIZING YOUR RSL
Use case #5: Cutting your RSL in half
Use case You just made an RSL and feel pretty good about yourself. But the client wants the app to load
even faster.
Solution Optimize your RSL by using Optimus Prime! ... er.. the optimizer

OPTIMIZING YOUR RSL
Half the size? Why don’t they make RSL’s for people?
WHAT IS THE OPTIMIZER It is a tool provided by Adobe to cut out the fat of any file, which is debug
information, markup data, and other suspicious characters.
WHAT IS THE RESULT In most cases it will reduce the file of your RSL by more than 50%
WHERE IS THE OPTIMIZER In your Flex SDK bin directory
HOW DO I USE IT like this!
optimizer
-keep-as3-metadata=\"Bindable,Managed,ChangeEvent,NonComittingChagneEvent,Transient\"
-input MyRsl.swf
-output optimized.swf

COLLABORATING VIA RSLS
Use case #6: Collaborative Work
WHY WOULD YOU WANT TO DO THAT To be used as a base for work to be expanded upon and shared
throughout a community that has a large base, such as:
Libraries (SVG)
Components (Flex.org libraries)
Frameworks (Nimbus, Cairngorm, Mate, PureMVC)
API’s (Facebook, Twitter)
Utilities (AS3 Core Lib, Internal Company Libraries)
HOW WOULD IT HELP The more people who it, the more likely it will be that it has already been cached
BASE Although RSLs are not the solution for a many user collaborative development of its “self”, it can act as
a very powerful, easy, and maintainable base to build on.

AUTOMATED BUILDS AND RSLS
Use case #7: Deploying RSLs
Use case You need to develop on your Flex Libraries, but what to deploy them as RSLs
Solution Use and automated build process (ANT, RAKE, etc) to create your RSLs

AUTOMATED BUILDS AND RSLS
Use case #7: Deploying RSLs
COMPILE Compile your SWC
EXTRACT Extract your SWF for your SWC
OPTIMIZE Optimize your SWF
MOVE Move your SWF to where you want it (maybe upload it)
COMPILE Compile your application
http://labs.adobe.com/wiki/index.php/Flex_3:Feature_Introductions:Flex_3_RSLs
http://www.oreillynet.com/pub/a/oreilly/digitalmedia/helpcenter/programmingflex3/chapter20.html?
page=9

SUMMARY
What was all that again?
Runtime Shared Library
Separates your base (framework, library, components, etc) from your application. The seperated files are
then cached for faster loading.
When should you use the Framework RSLs?
Pretty much always.
When should you use your own RSLs
When you have a big chunk of code that you don’t want to have to load in every time you make a change to
your application
All code samples can be downloaded at
http://www.chasebrammer.com/files/360flex.zip

CONTACT
Get a hold of that one guy
WEBSITE http://chasebrammer.com
EMAIL cbrammer@gmail.com
TWITTER chaseb
Seriously, come get my Business card, I have a whole case of em’