Design principles

GRASP

• 1 Patterns
  • 1.1 Creator
  • 1.2 Information Expert
  • 1.3 Controller
  • 1.4 Low Coupling
  • 1.5 High Cohesion
  • 1.6 Polymorphism
  • 1.7 Pure Fabrication
  • 1.8 Indirection
  • 1.9 Protected Variations

SOLID

S	SRP	Single responsibility principle the notion that an object should have only a single responsibility.
O	OCP	Open/closed principle the notion that “software entities … should be open for extension, but closed for modification”.
L	LSP	Liskov substitution principle the notion that “objects in a program should be replaceable with instances of their subtypes without altering the correctness of that program”. See also design by contract.
I	ISP	Interface segregation principle the notion that “many client specific interfaces are better than one general purpose interface.”[5]
D	DIP	Dependency inversion principle the notion that one should “Depend upon Abstractions. Do not depend upon concretions.”[5] Dependency injection is one method of following this principle.

http://www.codinghorror.com/blog/2009/02/the-ferengi-programmer.html

• SINGLE RESPONSIBILITY - DON'T MAKE A BIG BALL OF MUD.
• OPEN CLOSED - DON'T MAKE A THING THAT CAN BE INADVERTANTLY TROUNCED BY ANOTHER THING.
• LISKOV SUBSTITUTION - WHEN POSSIBLE MAKE THINGS MODULARLY SO YOU CAN CHANGE LESS LATER.
• INTERFACE SEGRATION - DON'T MAKE A CLIENT DEPEND ON INTERFACES THEY DON'T NEED.
• DEPENDENCY INVERSION - DON'T MAKE SOMETHING CONCRETELY DEPENDENT ON SOMETHING ELSE, RELY ON ABSTRACTIONS