Ports and Adapters Architecture | Hexagonal Architecture

1. Ports & Adapters
Ofir Attal, Front End Developer
linkedin/ofiratt github.com/ofiratt@Ofir_attalofira@wix.com

2. Hi.
I am Ofir Attal, a Front End Developer
Lithuania
Ukraine
Vilnius
Kiev
Dnipro
Wix Engineering Locations
Israel
Tel-Aviv
Be’er Sheva

3. Ports & Adapters
Architecture
01

4. the problem is Not writing code that works.

5. the problem is writing code that is
easy to Modify.

6. ✔ Maintainable
✔ Scalable
✔ Easy to add / remove features to
you need to understand
that your code will change.
Good code is:

8. hexagonal
architecture
Business Logic
Technical Details

9. Alistair
Cockburn

10. hexagonal
architecture
Business Logic
Technical Details
Ports & Adaptors
Ports & Adapters
is an architecture, that
prevents technical details
from infiltrating the business
logic.

11. MotorAdapterAirConditioner Motor
+m: Motor
+turnOn()
+turnOFF()
+motor: MotorAdapter
+cool()
+stop()
+spinCW()
+spinCCW()
implementing the Adapter
pattern Example
...
if(roomTemp > desireeTemp)
motor.turnOn();
...
...
motor.CCW();
...

12. Business Logic
Ports
Interface - API
The BL “knows it and only it”
Adapters
Implement the port
Keep ‘em Thin!
One for each external system

13. Business Logic
Ports
Interface - API
The BL “knows it and only it”
Adapters
Implement the port
Keep ‘em Thin!
One for each external system

15. ▪ Prevent external dependencies
from leaking into the code
▪ Anti-corruption layer
▪ They’re replaceable
Business Logic
how adaptors
help you

16. Code
Example
02

17. Tic tac toe
let’s do it!

18. interface TicTacToePort {
markCell(x, y);
...
}
import javax.swing.JTextField;
AdapterUI implement TicTacToePort {
public markCell(row, column) {
textField[row][column].setText(‘X’);
}
}
CoreLogic() {
TicTacToePort ticTacToePort;
think() {
if …
ticTacToePort.markCell(row, column);
}
}
Tic tac toe
business logic

19. interface TicTacToePort {
markCell(x, y);
...
}
import javax.swing.JTextField;
AdapterUI implement TicTacToePort {
public markCell(row, column) {
textField[row][column].setText(‘X’);
}
}
CoreLogic() {
TicTacToePort ticTacToePort;
think() {
if …
ticTacToePort.markCell(x, y);
}
}
Tic tac toe
port

20. interface TicTacToePort {
markCell(row, column;
...
}
import javax.swing.JTextField;
AdapterUI implement TicTacToePort {
public markCell(row, column) {
textField[row][column].setText(‘X’);
}
}
CoreLogic() {
TicTacToePort ticTacToePort;
think() {
if …
ticTacToePort.markCell(x, y);
}
}
Tic tac toe
adapter

21. UML
BL Low Details
<<Interface>>

22. Ports & Adapters
TDD
03

23. Growing Object - Oriented Software, Guided By Tests. Nat Pryce
Easy to classify
incidents
Business
logic
Technical
details

24. Growing Object - Oriented Software, Guided By Tests. Nat Pryce
Easy to test the BL
in unit tests

25. Growing Object - Oriented Software, Guided By Tests. Nat Pryce
Easy to validate
assumptions
in integration tests

26. OUR SOFTWARE WILL NEVER BE PERFECT.

27. public spinTheRolate(int userBetNumber) {
Random rand;
int rolateNumber = rand.nextInt(36);
if(userBetNumber == rolateNumber) {
system.print.out("user won");
}
else {
system.print.out("user lost");
}
}
code
Violations

28. public spinTheRolate(int userBetNumber) {
Random rand;
int rolateNumber = rand.nextInt(36);
if(userBetNumber == rolateNumber) {
userNotifications.won();
}
else {
userNotifications.lost();
}
}
interface UserNotifications {
public won();
public lost();
}
UserNotificationUI implements UserNotifications {
public won() { system.print.out("user won"); }
public lost() { system.print.out("user lost"); }
}
code
Violations

29. private getNewRolateBet() {
Random rand;
return rolateNumber = rand.nextInt(36);
}
public playUserBatFor(int userBetNumber) {
if(userBetNumber == getNewRolateBet())
userNotifications.won();
else
userNotifications.lost();
}
interface UserNotifications {
public won();
public lost();
}
UserNotificationUI implements UserNotifications {
public won() { system.print.out("user won"); }
public lost() { system.print.out("user lost"); }
}
code
Violations

30. 1.
keep the BUsiness
Logic clean!
2.
Keep The adapter
thin
2 takeaways
for ports & adapters

31. http://wiki.c2.com/?HexagonalArchitecture
http://wiki.c2.com/?PortsAndAdaptersArchitecture
https://spin.atomicobject.com/2013/02/23/ports-adapters-software-architecture/
http://alistair.cockburn.us/Hexagonal+architecture
http://www.natpryce.com/articles/000772.html
https://cleancoders.com/videos/clean-code
SOLID videos - https://cleancoders.com/videos/clean-code/solid-principles
resources

32. Thank You
linkedin/ofiratt github.com/ofiratt@Ofir_attalofira@wix.com

33. Q&A
linkedin/ofiratt github.com/ofiratt@Ofir_attalofira@wix.com