Jason Adams
Senior engineer at Impress.org with a love for mentoring and coaching growing devs, coming up with simple solutions to complex problems, and hanging out with my wife!
OOP + Design Patterns
=
Happy Developers
Jason Adams
@jasontheadams
Big times in
WordPress Land
1. PHP 5.6+
2. Gutenberg
3. No more IE 10
4. REST API
Time to use the features we've only stared longingly at!
Let's talk about some common problems
"It took me 4 hours to find this stupid bug."
"I'm... not even sure how this function works anymore."
"How did it even get that value!? That shouldn't be possible!"
"So where should I make this thing? Is here fine?"
Design Patterns
Yes,
Someone else already had that problem and, yes, they already solved it.
What Design Patterns are and are not
Are Not:
Are:
- A framework such as WordPress
- A plug-n-play library such as React
- Something you can copy and paste
Design
Pattern
Categories
1. Creational
2. Structural
3. Behavioral
Let's dive right in!
First up:
Value Objects
A scalar value is more than a value
Percentages
- Between -1 and 1
Temperature
- Has a unit (F/C/K)
Post Status
- Limited to fixed list: private, published, draft...
Key takeaways for
Value Objects
-
Each Value Object instance should represent a single (scalar) value.
- Keep the value property private.
-
Store everything you need to make your value meaningful.
-
Protect the value’s integrity.
Next up:
Singletons
Singletons
A common pattern in WordPress, especially in plugins, where the class only allows one instance of itself to exist. It looks so nifty...
BUT!
Singletons are nifty, but they aren't SOLID
Single Responsibility
Open/Close
Liskov Substitution
Interface Segregation
Dependency Inversion
Key takeaways for
Singletons
-
Don't use them.
- Use a Factory to manage your instance or Dependency Injection
Alain Schlesser has a great article on this with many well laid out alternatives:
Next up:
Abstract Factory
Case Study
The wild west of chair sales
Key takeaways for
Abstract Factory
-
Let the factory manage the conditions of the object creation.
- Use the same interface for the classes that may be returned.
-
Don’t mix creation with implementation.
Conclusion:
Design Patterns are your friend and mentor
Thanks!
Jason Adams
@jasontheadams
Get the slides
OOP + Design Patterns = Happy Developer
By Jason Adams
