Transcript Mach II at Macromedia Sean Corfield Director, Architecture An introduction to Mach II and its use on macromedia.com.

Mach II at Macromedia
Sean Corfield
Director, Architecture
An introduction to Mach II and its
use on macromedia.com
Overview
• An introduction to Mach II
• What Macromedia is doing with Mach II
• Lessons Learned - Good & Bad
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Introduction
• What is Mach II?
Definitions & Buzzwords
An overview of how it works
• Why use Mach II?
Pros & Cons
Alternatives
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What is Mach II? /i
• "Mach-II is a web-application framework
focused on easing software
development and maintenance."
mach-ii.com (official Mach II website)
• It's code that we can use as a
foundation for our applications
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What is Mach II? /ii
• Object-Oriented
• Strict Model View Controller structure
• Event-Based Implicit Invocation
Architecture
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What is Mach II? /iii
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What is Mach II? /iv
• Events
Generated by user (links, forms)
Generated by application code
• Example
User tries to login (event=login)
Login success (event=login_ok)
Login failure (event=login_bad)
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What is Mach II? /v
• Event Handlers
Specified in XML (mach-ii.xml)
Can notify "listener" CFCs
Can render views (HTML)
Can announce new events
Can use filters to process data and affect
the flow of control
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What is Mach II? /vi
• A simple event handler:
<event-handler event="showHome"
access="public">
<notify listener="newsManager"
method="getNews"
resultKey="request.news" />
<view-page name="homePage" />
</event-handler>
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What is Mach II? /vii
• Model - ColdFusion Components
Business Domain Objects
"listeners" (for handling events)
• View - CFML pages
Also layout templates, "pods" etc
• Controller - Mach II
XML configuration file
Core framework files
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What is Mach II? /viii
Mach II Application Structure
/appname
Application.cfm
index.cfm
/model
/view
/config
CFCs
.cfm pages
mach-ii.xml
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What is Mach II? /ix
• Extensibility
Filters
• CFCs that process data, announce events,
change flow of control
• Invoked explicitly by event handlers
Plugins
• CFCs that process data, announce events,
change flow of control
• Invoked implicitly at key points in the event
lifecycle
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Why use Mach II? /i
• "It helps ColdFusion developers build
maintainable applications by allowing
them to focus separately on the
independent parts of their applications:
the business model, the presentation
layer, the connecting logic - the flow of
the application."
corfield.org (unofficial Mach II website)
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Why use Mach II? /ii
• Good frameworks provide a "head start"
• Based on sound engineering principles
MVC design pattern
Implicit Invocation Architecture
• Standardization
Common structure for applications
• It supports "best practices"
Good OO design / heavy use of CFCs
Loose coupling / high cohesion
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Why use Mach II? /iii
• But . . .
• Frameworks
Require you use their style / idiom
Constrain how you develop applications
• Mach II requires you use
CFCs / OO / MVC / CFMX6.1
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Why use Mach II? /iv
• Alternatives?
Struts (built for Java)
• http://jakarta.apache.org/struts/
Fusebox (procedural, explicit)
• http://www.fusebox.org/
onTap (procedural, implicit)
• http://www.turnkey.to/ontap/
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Macromedia & Mach II
• Why did we choose Mach II?
• How are we contributing to Mach II?
• What applications use Mach II?
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Why we chose Mach II
• The macromedia.com team had
Heavy use of ColdFusion Components
Informal MVC approach in some apps
• But we wanted more standards and
more structure in our applications
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Contributing to Mach II
• Macromedia was an early adopter
Discovered bugs (& provided fixes)
Submitted enhancements (based on realworld usage scenarios)
Load testing & stability improvements
• Published Mach II Development Guide
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Applications using Mach II /i
• We started small
Active Content Resources administrator
• 6 filters, 14 event handlers, 2 listeners, 7 views
Breeze Leads application
• 4 filters, 13 event handlers, 2 listeners, 6 views
Some internal content management
applications
• This proved the framework for us
without taking much of a risk
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Applications using Mach II /ii
• Product Showcase [link]
6 filters, 81 event handlers, 16 listeners, 1 plugin,
42 views
• European Online Stores (HTML version) [link]
7 filters, 78 event handlers, 1 listener, 1 plugin, 45
views
• 14 Mach II applications in production or in
development…
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Lessons Learned
• Benefits of using Mach II
• Downsides to using Mach II
• Freedom within the framework
• Load testing & thread safety
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Benefits of using Mach II /i
• Able to leverage existing CFCs
Built an HTML version of Flash / CFC store in a
short space of time
• Implicit Invocation
Reduced coupling & dependencies
Easier to change application flow
• Strict MVC
Separation of presentation and logic
Declarative controller (XML)
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Benefits of using Mach II /ii
• What our engineers say
Mach II provides a head start on coding
Common code structure and very modular
nature of code make it easier to maintain
than ad hoc applications
Plugins and filters make it easy to extend
functionality
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Benefits of using Mach II /iii
• What our engineers say
Good MVC implementation allowing
application to be built views-first or
business-model-first as needed
XML controller makes incremental
development & testing easier
• Overall, a big win - Mach II is well-liked
"two enthusiastic thumbs up!"
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Downsides to using Mach II
• What our engineers say
Lack of documentation
Debugging / Tool support
• Some community tools are now appearing
Poor white space management
• Improved in 1.0.9
Thread safety is big, big issue
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Freedom within the framework /i
• There's more than one way to do things
Filters vs Plugins
Layouts, Pods
Form handling
Request scope vs Event object
Listener style
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Freedom within the framework /ii
• We used filters for
Security / login authentication
Persistence
Form handling
Localization
Caching
Omniture click-stream tracking
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Freedom within the framework /iii
• We used plugins for
Application initialization / parameters
Localization
Tracing / debugging / performance
analysis
• Note: two approaches to localization!
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Freedom within the framework /iv
• Layouts & Pods
Portal / Grid Layouts
Lots of small views, rendered to contentKey
variables (pods)
Use layout template views to assemble page
Usually announce event to assemble page
CompositeView design pattern
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Freedom within the framework /v
• Form handling
Beaner filter
• Code was written before <event-bean>
command was added!
Validation filter
• No custom form handling:
All basic bean-based code
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Freedom within the framework /vi
• Request scope vs Event object
We mostly follow the (original) Mach II
Development Guide recommendations
Mostly use a few request scope variables
as the API to views
Use a few event arguments where it is
clearer and more maintainable to do so
This is no longer considered best practice
for Mach II!
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Freedom within the framework /vii
• We have yet to choose one listener
style
Some applications use a single listener as
a facade for the business model
Some applications use one or two simple
"manager" listeners
Some applications use a lot of small,
single-function listeners
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Load testing & thread safety /i
• Mach II 1.0.9 is thread safe
Earlier versions of the framework were not!
Load testing highlighted random errors
• All CFCs are stored in application scope
Need to use 'var' scope for all local
declarations in all functions!
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Load testing & thread safety /ii
• You must also 'var' declare implicitly
created variables (from cfquery, cffile
etc)
• Example:
<cfset var results = 0 />
<cfquery name="results" …>
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Summary
• Mach II…
…is a good fit for the way we develop
applications: OO, MVC
…is based on a solid software
architecture: Implicit Invocation
…provides a common structure for our
applications that reduces coupling,
increases cohesion, eases maintenance
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Resources
• The official Mach II website
http://www.mach-ii.com/
• The unofficial Mach II website
http://www.corfield.org/machii/
• Mach II Development Guide
http://livedocs.macromedia.com/wtg/
public/machiidevguide/
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Mach II at Macromedia
• Questions & Answers?
• Sean A Corfield
• [email protected]
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