How Frameworks Can Kill Your Projects at XP Days Ukraine 2013 in Kiev

How frameworks
can kill your
projects

Sander Hoogendoorn

Principal Technology Officer
& Global Agile Thouhtleader Capgemini

And some patterns
to prevent you from getting killed

www.sanderhoogendoorn.com
www.speedbird9.com
@aahoogendoorn

Sander Hoogendoorn

2

Capgemini
 Principal technology officer
 Global agile thought leader
 Chief architect Accelerated Delivery Platform

Other






Author books on UML, agile (2)
Author +200 articles
Speaker +100 international conferences
Microsoft Partner Advisory Council .NET
Editorial boards & Advisory boards

Web
 www.sanderhoogendoorn.com
 www.speedbird9.com | www.smartusecase.com
 @aahoogendoorn
HOW FRAMEWORKS CAN KILL YOUR PROJECTS

©2012 Sander Hoogendoorn All Rights Reserved

On being a developer...

4



A small rectification …

5

Ukrainian



Agenda

6

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



Agenda

7

An short story
about frameworks

How frameworks can
get you in trouble

versus frameworks

The layer
supertype

Introducing the
descriptor pattern

The
manager-provider



Hofstadter’s Law
It always takes longer than you expect,
even when you take into account Hofstadter’s Law

MyFirstSurvey

9



MyFirstSurvey

10



Life is never easy
Frameworks, like pizzas, come in only two
sizes: too big and too small.

MyFirstSurvey

12



What’s it gonna be punk?

13
General purpose frameworks
Enterprise Library, Spring.Net, Castle,
NakedObjects, Accelerated Delivery Framework
(ADF), SubSonic

Single goaled frameworks – verticals

Single goaled frameworks – architectural

Dependency injection: ObjectBuilder, Unity,
Castle Windsor

User interface: Silverlight, ASP.NET MVC, WPF,
ASP.NET Ajax, Spring MVC

Logging: Log4Net, Logging Block,
Common.Logging

Process: UI Process Application Block, WF

Exception handling: Exception Handling Block
Apect orientation: PostSharp, SetPoint

Data: Entity Framework, Hibernate, Castle
ActiveRecord, CSLA

Search: Lucene.net, NLucene

Service s: WCF, WCF RIA

Domain: Entity Framework, Hibernate, NEO

Portals: DotNetNukeSpatial, Umbraco


Frameworks. CodePlex

14



Frameworks. www.csharpopensource.com

15



Frameworks. Microsoft Enterprise Library

16



Frameworks. Project Castle

17



Don’t believe the hype. It’s a SQL

18



Convincing the management to apply the framework (25.5 %)

19



Understanding the framework (56.4 %)

20



Convincing other developers to use the framework (23.6 %)

21



Convincing other developers to use the framework (23.6 %)

22



Training the developers (20 %)

23



The eye of the tiger

24



Agenda

25

An short story
about frameworks

How frameworks can
get you in trouble

versus frameworks

The layer
supertype

Introducing the
descriptor pattern

The
manager-provider



Applying
Frameworks
My software never has bugs.
It just develops random features

So glad you made it!

27

What if the author of our
favorite framework suddenly
stops developing it?

What if we require
additional features that
aren’t covered by our
framework?
And what if the new
version of our framework
is implemented totally
different?
What if we decide that
another framework
might be better than the
one we’re using now?

What if the framework
contains bugs?


More than anything, dependencies will kill your project

28



Kentucky Fried
Architecture
A short story about framework developers
and application developers

Pigs & Chickens

The framework
developer

30

The
application
developer


The customer is not always right

31



KFC Architecture. Entity Framework

32




33




34



Here’s …
beta!

Letting
the lunatics
run the asylum

I don’t care if it works on your machine!
We are not shipping your machine!

Hot or not?

37

Hot?

From hot to not?

Not?

WindowsRT
PCL
HTML5
LightSwitch
WCF RIA Services
Silverlight 4.0?
ASP.NET MVC 3
MEF
jQuery
NService Bus
Entity Framework Code First
Xamarin
TypeScript

Expression Blend
ASP.NET Ajax
REST
Unity
BizTalk
Surface
Duet
SketchFlow
Azure Services
ADO.NET Data
Services
ASP.NET Dynamic
Data
WPF

Entity Framework 2.0
LINQ2SQL
LINQ2Entities
Entity Data Model
Dublin
DSL’s
Silverlight 2.0
F#
ASP.NET
PopFly
M
Oslo
MGrammar



Be a genius

38

Metro?

WTF? I just figured
out ASP.NET MVC



Here’s Johnny! ASP.NET MVC

39



Here’s Johnny! ASP.NET MVC

40



No strings
attached
It’s only in theory
that practice and theory are the same

MyFirstSurvey

42



Changing base classes. NHibernate / Log4Net

43



Changing base classes. NHibernate / Log4Net

44



Yes, your
frameworks
version too

Programming is like sex. One mistake and you
have to support it for the rest of your life

It ain’t over till it’s over

46



Missing base classes. Workflow Foundation 4.0

47



Missing base classes. Workflow Foundation 4.0

48



Enterprise Library & Retirement

49



“Evolving” the Reflection API

50




51




52



Agenda

54

An short story
about frameworks

How frameworks can
get you in trouble

versus frameworks

The layer
supertype

Introducing the
descriptor pattern

The
manager-provider



Sound
architecture
Architecture starts when you carefully put
two bricks together. There it begins.

(Software.Architecture != List<Framework>)

A software architecture

57



Creating your architecture

58

What to do?
 Identify your architectural requirements
 Set up a (layered) architecture
 Identify layers and layer elements

 List the elements responsibilities
 List the elements collaborations
 And only then map to frameworks

 Create a thin “umbrella” of independence responsible for
managing dependencies

 “Wrap” frameworks to avoid too many dependencies



Presentation
Silverlight
XAML
ASPX

Process

Pages
UserControls
Panels

Entities
(from EF)
Domain
Services

Use cases
Workflow
MVVM?
MVP?

Domain objects / Entities
Factories / Repositories
Enums / Value objects / Smart references
[Mapping]

Domain

Metadata

Service gateways
Service locators
[Mapping]

Data / Services

COBOL
Outside world

SAP

BizTalk

Java

Entity Framework
LINQ
Nhibernate?
WCF?

Databases
Services / ESB



Agenda

61

An short story
about frameworks

How frameworks can
get you in trouble

versus frameworks

The layer
supertype

Introducing the
descriptor pattern

The
manager-provider



Layer supertype
From a developers point of view
the user is a peripheral that types
when you issue a read request.

Layer Supertype

63

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



Layer Supertype. ASP.NET MVC

64



Layer Supertype. ASP.NET MVC

65



Pages
UserControls
Panels

Presentation

Process

Use cases
Workflow

Domain

Domain objects / Entities
Factories / Repositories
Enums / Value objects / Smart references
[Mapping]
Service gateways
Service locators
[Mapping]

Data / Services

Exact
Outside world

SAP

BizTalk

Java

Databases
Services / ESB



Layer Supertype. Using a layer supertype

67



Layer Supertype. Reasoning about layer supertypes

68



Layer Supertype. Extension methods on layer supertypes

69



Agenda

70

An short story
about frameworks

How frameworks can
get you in trouble

versus frameworks

The layer
supertype

Introducing the
descriptor pattern

The
manager-provider



Descriptor
Always code as if the guy
who ends up maintaining your code
will be a violent psychopath
who knows where you live.

I know nothing. I’m from Barcelona

72

What is the matter
Mister Fawlty?

The problem Manuel, 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



Descriptor. The problem

73



Descriptor. The problem

74



Enum?

75



String Collection?

76



String Collection

77



I know nothing. I’m from Barcelona

78

Descriptor
Defines a restricted but
application specific
extendible list of
definitions

Useful when
 Enums can not be inherited
 Framework defines enumeration

types that need to be extended in
application code

 Define layer supertype using
reflection

 Pre-define frequently used
instances



Descriptor Pattern

79



Descriptor Pattern. Definition

80



Descriptor Pattern. Extending the definition

81



Descriptor Pattern. Use in framework

82



Descriptor Pattern. Use in application

83



MyFirstSurvey

84



Descriptor Pattern. Use in ASP.NET MVC

85



Descriptor Pattern. Use in ASP.NET MVC

86



Agenda

87

An short story
about frameworks

How frameworks can
get you in trouble

versus frameworks

The layer
supertype

Introducing the
descriptor pattern

The
manager-provider



Dependency
injection
XML is like violence.
If it doesn’t solve your problems,
you are not using enough of it.

Dependency Injection. A contagious disease?

89

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

So …

 Call functionality without having to know

 Single or multiple implemenations need

the actual implementation

 Implement replaceable services

 Apply implementations in different contexts
 Plug-in services at run-time

 Single topic services
to be handled, which differs dependant
on context, like with Windows API,
logging or error handling

 Unit testing



Different variations?

90
Did you know that there
are different types
of this dependency injection?

Yeah, sure. There’s

 Constructor injection

 Property (setter) injection
 And even manual injection
Arggh…

Who cares doc?



Dependency injection. Manual injection

92

c



Dependency injection. what to plug in

93



Manager –
Provider
"Teamwork is a lot of people doing what I say“
Marketing executive, Citrix Corporation

Manager-Provider Pattern

95

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. ValidationManager

96



Interface

97



Manager. Initialization (using dependency injection)

98



Configuration of implementation

99



Configuration of implementation

100



Manager. Executing methods

101



Client. Calling methods

102



Client. Extending

103



Manager-Provider pattern

104

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

 Writing platform independent code



Manager-Provider pattern

105

Use for
 Task Management
 View Management
 Binding and Persisting

 Resource Management
 State Management
 Logging

 Datasource interaction
 Encryption
 Authorization

 Testing!


Creating your
architecture
Software architecture is like deodorant.
Those who need it the most don’t use it.

Creating your architecture

107

What to do?
 Identify your architectural requirements
 Set up a (layered) architecture
 Identify layers and layer elements

 List the elements responsibilities
 List the elements collaborations
 And only then map to frameworks

 Create a thin “umbrella” of independence responsible for
managing dependencies

 “Wrap” frameworks to avoid too many dependencies



Too many layers

108



References
and questions
www.sanderhoogendoorn.com
www.smartusecase.com
www.speedbird9.com
sander.hoogendoorn@capgemini.com
sander@ditisagile.nl
@aahoogendoorn

How Frameworks Can Kill Your Projects at XP Days Ukraine 2013 in Kiev

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