And patterns to help you avoid getting killed Sander Hoogendoorn | Principal Technology Officer | Capgemini | @aahoogendoorn ARC203 - HOW FRAMEWORKS CAN KILL YOUR PROJECTS
May 15, 2015
And patterns to help you avoid getting killed
Sander Hoogendoorn | Principal Technology Officer | Capgemini | @aahoogendoorn
ARC203 - HOW FRAMEWORKS CAN KILL YOUR PROJECTS
2HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
Capgemini
� Principal technology officer
� Global agile thought leader
� Chief architect Accelerated Delivery Platform (ADP)
Other
� Microsoft Partner Advisory Council .NET
� Author books and articles in international magazines
� Appreciated speaker at international conferences
� Columns in several magazines
� Editorial boards
Web
� www.sanderhoogendoorn.com
� www.smartusecase.com
� Twitter: @aahoogendoorn
SANDER HOOGENDOORN
3HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
ARC203 – How frameworks can kill your projects
� Tuesday 12:00
� Hall 3.2 Interactive 2
ARC202 - How frameworks can kill your projects
� Wednesday 13:20
� Hall 7.1b London 2
ARC203 – How frameworks can kill your projects (repeat)
� Thursday 10:30
� Hall 3.2 Interactive 6
ARC205 – How smart use cases drive web development
� Friday 10:30
� Hall 7.3 Berlin 1
SANDER HOOGENDOORN – TECHED 2010 SESSIONS
4HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
AGENDA
An short story
about frameworks
How frameworks can
get you in trouble
Software architecture
versus frameworks
The layer
supertype
Introducing the
descriptor pattern
The
manager-provider
5HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
AGENDA
An short story
about frameworks
How frameworks can
get you in trouble
Software architecture
versus frameworks
The layer
supertype
Introducing the
descriptor pattern
The
manager-provider
It always takes longer than you expect,
even when you take into account Hofstadter’s Law
HOFSTADTER’S LAW
7HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
MYFIRSTSURVEY
8HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
MYFIRSTSURVEY
Frameworks, like pizzas, come in only two sizes: too big and too small.
LIFE IS NEVER EASY …
10HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
MYFIRSTSURVEY
11HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
WHAT’S IT GONNA BE PUNK?General purpose frameworks
Enterprise Library, Spring.Net, Castle, NakedObjects,
Accelerated Delivery Framework (ADF), SubSonic
Single goaled frameworks – verticals
Dependency injection: ObjectBuilder, Unity, Castle
Windsor
Logging: Log4Net, Logging Block, Common.Logging
Exception handling: Exception Handling Block
Apect orientation: PostSharp, SetPoint
Search: Lucene.net, NLucene
Portals: DotNetNukeSpatial, Umbraco
Single goaled frameworks – architectural
User interface: Silverlight, ASP.NET MVC, WPF, ASP.NET
Ajax, Spring MVC
Process: UI Process Application Block, WF
Domain: Entity Framework, Hibernate, NEO
Data: Entity Framework, Hibernate, Castle ActiveRecord, CSLA
Service s: WCF, WCF RIA
12HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
FRAMEWORKS - CODEPLEX
13HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
FRAMEWORKS – WWW.CSHARPOPENSOURCE.COM
14HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
FRAMEWORKS – MICROSOFT ENTERPRISE LIBRARY
15HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
FRAMEWORKS – PROJECT CASTLE
16HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
DON’T BELIEVE THE HYPE – IT’S A SQL
17HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
CONVINCING THE MANAGEMENT TO APPLY THE FRAMEWORK (25.5 %)
18HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
UNDERSTANDING THE FRAMEWORK (56.4 %)
19HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
CONVINCING OTHER DEVELOPERS TO USE THE FRAMEWORK (23.6 %)
20HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
TRAINING THE DEVELOPERS (20 %)
21HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
THE EYE OF THE TIGER
22HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
AGENDA
An short story
about frameworks
How frameworks can
get you in trouble
Software architecture
versus frameworks
The layer
supertype
Introducing the
descriptor pattern
The
manager-provider
My software never has bugs. It just develops random features
APPLYING FRAMEWORKS
24HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
SO GLAD YOU MADE IT!
What if we require
additional features that
aren’t covered by our
framework?
What if we decide that
another framework might
be better than the one
we’re using now?
What if the author of our
favorite framework suddenly
stops developing it?
What if the framework
contains bugs?
And what if the new version
of our framework is
implemented totally
different?
25HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
MORE THAN ANYTHING, DEPENDENCIES WILL KILL YOUR PROJECT
A short story about framework developers and application developers
KENTUCKY FRIED ARCHITECTURE
27HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
THE CUSTOMER IS NOT ALWAYS RIGHT
28HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
PIGS & CHICKENS
The application
developer
The framework
developer
29HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
KFC ARCHITECTURE – ENTITY FRAMEWORK
30HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
KFC ARCHITECTURE – ENTITY FRAMEWORK
31HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
KFC ARCHITECTURE – ENTITY FRAMEWORK
I don’t care if it works on your machine! We are not shipping your machine!
LETTING THE LUNATICS RUN THE ASYLUM
Here’s … beta!
33HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
ON THE WRONG TRACK
34HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
HOT OR NOT?
Hot? From hot to not? Not?
HTML5
LightSwitch
WCF RIA Services
Silverlight 4.0
ASP.NET MVC 2 (3?)
ASP.NET Dynamic Data
ADO.NET Data Services
MEF
Azure Services
jQuery
NService Bus
Oslo
M
MGrammar
Expression Blend
ASP.NET Ajax
REST
Dublin
BizTalk
Surface
Duet
SketchFlow
Entity Framework 2.0
LINQ2SQL
LINQ2Entities
Entity Data Model
WPF
Unity
DSL’s
Silverlight 2.0
F#
ASP.NET
PopFly
35HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
HERE’S JOHNNY! – ASP.NET MVC
36HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
HERE’S JOHNNY! – ASP.NET MVC
It’s only in theory that practice and theory are the same
NO STRINGS ATTACHED
38HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
MYFIRSTSURVEY
39HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
CHANGING BASE CLASSES – – NHIBERNATE / LOG4NET
40HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
CHANGING BASE CLASSES – NHIBERNATE / LOG4NET
Programming is like sex.
One mistake and you have to support it for the rest of your life
YES, YOUR FRAMEWORKS VERSION TOO
42HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
IT AIN’T OVER TILL IT’S OVER
43HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
MISSING BASE CLASSES – WORKFLOW FOUNDATION 4.0
44HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
MISSING BASE CLASSES – WORKFLOW FOUNDATION 4.0
HOW TO AVOID GETTING KILLED
46HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
AGENDA
An short story
about frameworks
How frameworks can
get you in trouble
Software architecture
versus frameworks
The layer
supertype
Introducing the
descriptor pattern
The
manager-provider
Architecture starts when you carefully put two bricks together. There it begins.
SOUND ARCHITECTURE
(SOFTWARE.ARCHITECTURE != LIST<FRAMEWORK>)
49HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
A SOFTWARE ARCHITECTURE
50HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
Presentation
Process
Domain
Data / Services
Outside world
Pages
UserControls
Panels
Use cases
Workflow
Domain objects / Entities
Factories / Repositories
Enums / Value objects / Smart references
[Mapping]
Service gateways
Service locators
[Mapping]
Databases
Services / ESB
Exact SAP BizTalk Java
Silverlight
XAML
Entities
(from EF)
Domain
Services
Metadata
Entity Framework
LINQ
Nhibernate?
MVVM?
MVP?
51HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
THE GOOD, THE BAD AND THE UGLYDependencies
� Using frameworks is simply good, gringo
� However, being dependant on third parties
can put your project at risk
� How stable are the frameworks you use?
� How stable is the framework vendor?
Minimize dependencies
� Map frameworks to your software architecture,
not vice versa
� Define your own layer supertypes
� Wrap framework functionality
� Apply manager-provider pattern
� Implement extension methods if all fails
52HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
AGENDA
An short story
about frameworks
How frameworks can
get you in trouble
Software architecture
versus frameworks
The layer
supertype
Introducing the
descriptor pattern
The
manager-provider
From a programmer's point of view the user is a peripheral
that types when you issue a read request.
LAYER SUPERTYPE
54HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
LAYER SUPERTYPE What’s a layer supertype Ollie?
� Acts as a supertype for all types in
its layer
� All types inherit from the layer
supertype
Well Stan, it’s characteristics are
� Name expresses common behaviour
� Forces common features on all inherited types
� Ideal starting point for services
� Initially the layer supertype is empty
� Reserve layer supertype for future additions
� Extension methods don’t (always) help, you know
55HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
LAYER SUPERTYPE – ASP.NET MVC
56HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
LAYER SUPERTYPE – ASP.NET MVC
57HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
Presentation
Process
Domain
Data / Services
Outside world
Pages
UserControls
Panels
Use cases
Workflow
Domain objects / Entities
Factories / Repositories
Enums / Value objects / Smart references
[Mapping]
Service gateways
Service locators
[Mapping]
Databases
Services / ESB
Exact SAP BizTalk Java
58HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
LAYER SUPERTYPE – USING A LAYER SUPERTYPE
59HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
LAYER SUPERTYPE – DEFINE SERVICES ON LAYER SUPERTYPES
60HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
LAYER SUPERTYPE – EXTENSION METHODS ON LAYER SUPERTYPES
61HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
AGENDA
An short story
about frameworks
How frameworks can
get you in trouble
Software architecture
versus frameworks
The layer
supertype
Introducing the
descriptor pattern
The
manager-provider
Always code as if the guy who ends up maintaining your code
will be a violent psychopath who knows where you live.
DESCRIPTOR
63HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
I KNOW NOTHING. I’M FROM BARCELONA
What is the matter
Mister Fawlty?
The problem Manual, is that
� I want to use constants in my
application
� But I want to define them in my
framework and extend them in my
application
� Enumeration won’t do – there’s no
inheritance
64HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
DESCRIPTOR – THE PROBLEM (1)
65HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
DESCRIPTOR – THE PROBLEM (2)
66HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
ENUM?
67HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
STRING COLLECTION?
68HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
STRING COLLECTION
69HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
I KNOW NOTHING. I’M FROM BARCELONA
Descriptor
Defines a restricted but
application specific
extendible list of
definitions
Useful when
� Enums can not be inherited
� Framework defines enumerationtypes that need to be extended in application code
� Define layer supertype usingreflection
� Pre-define frequently used instances
70HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
DESCRIPTOR PATTERN
71HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
DESCRIPTOR PATTERN - DEFINITION
72HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
DESCRIPTOR PATTERN – EXTENDED DEFINITION
73HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
DESCRIPTOR PATTERN – USE IN FRAMEWORK
74HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
DESCRIPTOR PATTERN – USE IN APPLICATION
75HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
MYFIRSTSURVEY
76HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
DESCRIPTOR PATTERN – USE IN ASP.NET MVC
77HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
DESCRIPTOR PATTERN – USE IN ASP.NET MVC
78HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
AGENDA
An short story
about frameworks
How frameworks can
get you in trouble
Software architecture
versus frameworks
The layer
supertype
Introducing the
descriptor pattern
The
manager-provider
XML is like violence.
If it doesn’t solve your problems, you are not using enough of it.
DEPENDENCY INJECTION
80HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
A NEW DISEASE?What do you think it is?
Create true separation between definition and implementation, so that the two can vary independently and can be replaced easily
Looks like a typical case of dependency
injection to me
� Call functionality without having to know
the actual implementation
� Implement replaceable services
� Apply implementations in different contexts
� Plug-in services at run-time
So …
� Single topic services
� Single or multiple implemenationsneed to be handled, which differsdependant on context, like withWindows API, logging or errorhandling
� Unit testing
81HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
DIFFERENT VARIATIONS?Did you know that there
are different types of this
dependency injection?
Arggh…
Yeah, sure. There’s
� Constructor injection
� Property (setter) injection
� And even manual injectionWho cares doc?
82HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
DEPENDENCY INJECTION – CONSTRUCTOR INJECTION
83HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
DEPENDENCY INJECTION – MANUAL INJECTION
c
84HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
DEPENDENCY INJECTION – WHAT TO PLUG IN
Yes, XML will hurt you too!
"Teamwork is a lot of people doing what I say“
Marketing executive, Citrix Corporation
MANAGER – PROVIDER
86HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
Definition
� Create a simple static facade (manager) for
a (set of) interfaced implementations
(providers)
In practice
� Manager holds one or a collection of
providers
� Provider implement a particular interface
� Manager has methods to call methods
from interface
� At run-time, using dependency injection,
actual providers are injected
MANAGER-PROVIDER PATTERN
87HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
MANAGER – VALIDATIONMANAGER
88HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
INTERFACE
89HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
MANAGER – INITIALIZATION (USING DEPENDENCY INJECTION)
90HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
CONFIGURATION OF IMPLEMENTATION
91HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
MANAGER - EXECUTING METHODS
92HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
CLIENT – CALLING METHODS
93HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
Useful when
� Generic services need to be called, which may have different implementations
� Manager prevents having to loop through each of a list of providers
� Flexibility to add or remove providers without changing application code
� Providers differ e.g. in development code, test code or deployed code
Use for
� Task Management
� View Management
� Binding and Persisting
� Resource Management
� State Management
� Logging
� Datasource interaction
� Testing!
MANAGER-PROVIDER PATTERN
94HOW FRAMEWORKS CAN KILL YOUR PROJECTS©2010 Capgemini. All Rights Reserved
THE GOOD, THE BAD AND THE UGLYDependencies
� Using frameworks is simply good, gringo
� However, being dependant on third parties
can put your project at risk
� How stable are the frameworks you use?
� How stable is the framework vendor?
Minimize dependencies
� Map frameworks to your software architecture,
not vice versa
� Define your own layer supertypes
� Wrap framework functionality
� Apply manager-provider pattern
� Implement extension methods if all fails
www.accelerateddeliveryplatform.com
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www.sanderhoogendoorn.com | www.smartusecase.com
Twitter: @aahoogendoorn
REFERENCES AND QUESTIONS