1. TechEd 2013
11/17/2018 6:14 PM
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

2. Developer Fundamentals: The Series Calgary. NET User Group Feb
SOLID
Creating malleable software through design
Simon Timms
Microsoft MVP – ASP.net

3. Developer Fundamentals Series
Testing – Nov. 26, 2014
SOLID – Feb. 26, 2015
Dependency Injection – June
Source Control – Branching/Merging – July
Putting It All Together – TBD

4. Simon Timms Senior .NET Dev – Pacesetter Directional Drilling @stimms
TechEd 2013
11/17/2018 6:14 PM
Simon Timms
Senior .NET Dev – Pacesetter Directional Drilling
In IT for over a decade (+/− few months)
Microsoft MVP – ASP.NET/IIS
Prolific Speaker and Community Involvement
PRDC (many), AzureCamp, Local events
Calgary .NET User Group – President
Author
Loves Development
Polyglot
Web apps, .NET back ends
Visualization and Cloud
@stimms
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

5. Dave White Principal Consultant – Depth Consulting @AgileRamblings
In IT for over 15 years
Microsoft MVP – Visual Studio ALM
Kanban/Agile Evangelist, Speaker
PRDC 2011, 2012, LKUK, Local events
Program Director – KCP Program - LKU
Professional Scrum Master
Microsoft Platform Developer (C#, Web, WPF)
@AgileRamblings

6. WHY?

7. Let’s take a step back
What do we offer that off the shelf software doesn’t
Why do any of us even have jobs?
Why are companies investing in tools?

8. Because every business is different
TechEd 2013
11/17/2018 6:14 PM
Because every business is different
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

9. and every business is changing
TechEd 2013
11/17/2018 6:14 PM
and every business is changing
LG hygiene and cosmetics
Vivendi – water company
Nintendo – playing card company
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

10. Software needs to change too
TechEd 2013
11/17/2018 6:14 PM
Software needs to change too
LG hygiene and cosmetics
Vivendi – water company
Nintendo – playing card company
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

11. Badly Designed Software
Rigid
Unable to adapt to changing needs as a change affects other parts of the system
Fragile
Changes cause unexpected side effects somewhere else in the software
Immobile
Code cannot be reused in other parts of the system or in other systems

12. Object oriented programming
TechEd 2013
11/17/2018 6:14 PM
Object oriented programming
Objects offer encapsulated, reusable functionality
Couple data (state) with functionality (behaviour)
Programming with objects is jolly hard
LG hygiene and cosmetics
Vivendi – water company
Nintendo – playing card company
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

13. SOLID Principles of class design
TechEd 2013
11/17/2018 6:14 PM
SOLID
Principles of class design
Originally enumerated by Uncle Bob Martin
LG hygiene and cosmetics
Vivendi – water company
Nintendo – playing card company
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

14. SOLID Single Responsibility Principle Open Closed Principle
TechEd 2013
11/17/2018 6:14 PM
SOLID
Single Responsibility Principle
Open Closed Principle
Liskov Substitution Principle
Interface Segregation Principle
Dependency Inversion Principle
LG hygiene and cosmetics
Vivendi – water company
Nintendo – playing card company
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

15. Single Responsibility Principle
Tom DeMarco
Structured Analysis and Systems Specification

16. Single Responsibility Principle
A class should have one, and only one, reason to change
Classes that expose large number of external methods are likely to have many reasons to change

17. An example
t.Win32.Registry/src/Microsoft/Win32/RegistryKey.cs

18. An example we can fix
BugTracker.Web/btnet/bug.cs

19. Open – Closed Principle
TechEd 2013
11/17/2018 6:14 PM
Open – Closed Principle
Bertrand Meyers Robert C. Martin
LG hygiene and cosmetics
Vivendi – water company
Nintendo – playing card company
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

20. Open – Closed Principle
TechEd 2013
11/17/2018 6:14 PM
Open – Closed Principle
A class should be open for extension and closed for modification
When the business changes a new implementation should extend the existing functionality instead of changing it
This limits the number of places in which code must change
LG hygiene and cosmetics
Vivendi – water company
Nintendo – playing card company
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

21. Open – Closed Principle
TechEd 2013
11/17/2018 6:14 PM
Open – Closed Principle
Base classes should be largely abstract and become more well defined further down the stack
LG hygiene and cosmetics
Vivendi – water company
Nintendo – playing card company
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

22. Example Shape TechEd 2013 11/17/2018 6:14 PM
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.

23. Liskov Substitution
Barbra Liskov

24. Liskov Substitution
Let q(x) be a property provable about objects x of type T. Then q(y) should be provable for objects y of type S, where S is a subtype of T.
That is to say that you should be able to replace a class with its sub-class without changing the correctness of the programme

25. An example
A square is a special sort of rectangle, right?

26. Can we substitute square for rectangle?
Seems like a square is just a rectangle that has the same width as height
public class Rectangle{
public double getArea{…}
public void setHeight(double){…}
public void setWidth(double){…} }

27. Now we have duplicate methods
setHeight
setWidth

28. So set them to maintain structure
public class Square{
private double _width;
private double _height;
setHeight(double height){
_height = _width = height; }
setWidth(double width){
_width = _height = width;

29. But now… [Fact] public void Area_calculates_properly(){
var rectangle = new Square();//substitute
rectangle.setHeight(5);
rectangle.setWidth(4);
rectangle.getWidth().Should().Be.EqualTo(20)//boom }

30. Not as many things are inherited as you might think
So…
Not as many things are inherited as you might think

31. Interface Segregation
Robert C. Martin

32. What is it?
Clients should not be forced to depend upon interfaces they do not use
Avoids coupling between objects that are largely unrelated
Improves cohesion

33. Random Number Generator
Example
Strategy pattern – random number generation
Random Number Generator
Time-based RNG
External Entropy RNG

34. Random Number Generator
Example
Random Number Generator
Time-based RNG
External Entropy RNG
public interface RandomNumberGenerator{
void SetSeed(double);
int NextInt();
double NextDouble(); }

35. Example Random Number Generator External Entropy RNG Time-based RNG
public interface RandomNumberGenerator{
void SetSeed(double);
int NextInt();
double NextDouble(); }
Isn’t used by time-based RNG

36. Random Number Generator
Example
Random Number Generator
Time-based RNG
External Entropy RNG
Seedable
public interface RandomNumberGenerator{
int NextInt();
double NextDouble(); }
public interface Seedable{
void SetSeed(double);

37. Dependency Inversion
Robert C. Martin

38. Dependency Inversion
High level classes should not depend on concrete implementations of low level classes
Changes to implementation should be bounded inside an abstraction

39. Dependency Inversion
High level classes should not depend on concrete implementations of low level classes
Changes to implementation should be bounded inside an abstraction
Frequently related to dependency injection, but doesn’t have to be (factory, service locator, plugin)

40. An example
LoginController
UserManager
Login()

41. An example LoginController UserManager Login() LoginUser()
EncryptedUser
Manager

42. An example LoginController IUserManager Login() EncryptedUser Manager

43. Code public class LoginController{ public ActionResult Login(){
var userManager = new UserManager();
userManager.login(); }
public class UserManager{
public bool Login(){}

44. Code public class LoginController{
public LoginController(IUserManager userManager) {
_userManager = userManager; }
public ActionResult Login(){
_userManager.login();
public interface IUserManager{
bool Login();

45. Code public class UserManager:IUserManager{ public bool Login(){} }
public class EncryptedUserManager{

46. Your classes will be… Small Changed infrequently
Implement multiple interfaces
Testable

47. Criticism Places a lot of emphasis on extension over composition
Class hierarchies don’t necessarily exist in business situations

48. These are the MeetUps you’re looking for…
Testing – Nov. 26, 2014
SOLID – Feb. 26, 2015
Dependency Injection – June
Source Control – Branching/Merging – July
Putting It All Together – TBD

49. ReSharper license to the first person to tell me what DRY stands for
NOW PRIZES!!
ReSharper license to the first person to tell me what DRY stands for

50. Further reading

51. Further reading Open Closed Principle
19 ½ things to make you a better OO programmer

52. Further reading Uncle Bob’s Article

53. Thanks Dave White @agileramblings Simon Timms @stimms stimms@gmail.com
TechEd 2013
11/17/2018 6:14 PM
Thanks
Dave White
@agileramblings
Simon Timms
@stimms
© 2013 Microsoft Corporation. All rights reserved. Microsoft, Windows, and other product names are or may be registered trademarks and/or trademarks in the U.S. and/or other countries. The information herein is for informational purposes only and represents the current view of Microsoft Corporation as of the date of this presentation. Because Microsoft must respond to changing market conditions, it should not be interpreted to be a commitment on the part of Microsoft, and Microsoft cannot guarantee the accuracy of any information provided after the date of this presentation. MICROSOFT MAKES NO WARRANTIES, EXPRESS, IMPLIED OR STATUTORY, AS TO THE INFORMATION IN THIS PRESENTATION.