How to expand your current functionality without change existing javascript code with immediate function invocation.

1. Bake your cake
with
SOLID design principles and
Java Script
Anuradha Bandara

2. The SOLID Design Principles
• Single Responsibility Principle
• Open / Close Principle
• Liskov Substitution Principle
• Interface Segregations Principle
• Dependency Inversion Principle

3. Single Responsibility
Principle
• The SRP states that each class or
similar unit of code should have one
responsibility only and, therefore, only
one reason to change.

4. Open / Close Principle
• The OCP states that all classes and
similar units of source code should be
open for extension but closed for
modification.

5. Liskov Substitution Principle
• The LSP specifies that functions that
use pointers of references to base
classes must be able to use objects of
derived classes without knowing it.

6. Interface Segregations
Principle
• The ISP specifies that clients should not
be forced to depend upon interfaces
that they do not use. Instead, those
interfaces should be minimised.

7. Dependency Inversion
Principle
• The DIP states that high level modules
should not depend upon low level
modules and that abstractions should
not depend upon details.

8. Lets Do Code…
• Your Manager ask you to create a cake.
CakeMaker.js

9. Lets Do Code…
• You wrote a code. Test it. All works
fine.
• After one week Manager comes again
and ask functional expansions for your
code.
• Here add more functionalities without
changing existing code

10. Lets Do Code…
CakeDecorator.js

11. Lets Do Code…
CakeOrderManager.js

12. Lets Do Code…
• Here you instantiate javascript object
without polluting global space.
− Window.cakeMaker
• Then you add more functionalities to
the object

13. Summary
• Using javascript immediate functions
− Satisfy SOLID principles
− Gain high maintainable code
− Gain high reusability code

14. Thank you