🎭Design Patterns

Design Patterns in Pharmacy

Updated 2026-05-15

10 min read

Design Patterns in Pharmacy

Introduction

In the realm of software development, especially within specialized fields like healthcare, adhering to well-established design patterns can significantly enhance the quality and maintainability of your applications. This tutorial delves into how design patterns can be applied to improve pharmacy software systems. We'll explore various patterns that are particularly useful in this domain, providing both theoretical insights and practical examples.

Concept

Design patterns are reusable solutions to common problems encountered during software development. They provide a standardized approach to solving issues, making the codebase more readable, maintainable, and scalable. In the context of pharmacy software, these patterns can help manage complex workflows, ensure data integrity, and improve user interactions.

Common Design Patterns in Pharmacy Software

Singleton Pattern: Ensures that only one instance of a class is created and provides a global point of access to it.
Factory Method Pattern: Defines an interface for creating an object, but lets subclasses decide which class to instantiate.
Observer Pattern: A subject maintains a list of its dependents, called observers, and notifies them automatically of any state changes.
Strategy Pattern: Enables selecting an algorithm at runtime.
Adapter Pattern: Allows objects with incompatible interfaces to collaborate.

Examples

Let's dive into some practical examples of how these patterns can be applied in pharmacy software systems.

Singleton Pattern

In a pharmacy system, there might be a need for a single instance of a class that manages inventory data. The Singleton pattern ensures that only one such instance exists throughout the application.

JavaScript

1class InventoryManager {
2static instance;
3 
4constructor() {
5  if (InventoryManager.instance) {
6    return InventoryManager.instance;
7  }
8  this.inventory = {};
9  InventoryManager.instance = this;
10}
11 
12addItem(item, quantity) {
13  this.inventory[item] = quantity;
14}
15 
16getItemQuantity(item) {
17  return this.inventory[item];
18}
19}
20 
21// Usage
22const manager1 = new InventoryManager();
23manager1.addItem('Aspirin', 50);
24 
25const manager2 = new InventoryManager();
26console.log(manager2.getItemQuantity('Aspirin')); // Output: 50
27 
28console.log(manager1 === manager2); // Output: true

Factory Method Pattern

The Factory Method pattern can be used to create different types of prescription objects based on input parameters.

JavaScript

1class Prescription {
2constructor(drug, quantity) {
3  this.drug = drug;
4  this.quantity = quantity;
5}
6 
7dispense() {
8  console.log(`Dispensing ${this.quantity} units of ${this.drug}`);
9}
10}
11 
12class ControlledPrescription extends Prescription {
13dispense() {
14  console.log(`Dispensing controlled substance: ${this.quantity} units of ${this.drug}`);
15}
16}
17 
18class PrescriptionFactory {
19createPrescription(drug, quantity, isControlled) {
20  if (isControlled) {
21    return new ControlledPrescription(drug, quantity);
22  } else {
23    return new Prescription(drug, quantity);
24  }
25}
26}
27 
28// Usage
29const factory = new PrescriptionFactory();
30const prescription1 = factory.createPrescription('Ibuprofen', 20, false);
31prescription1.dispense(); // Output: Dispensing 20 units of Ibuprofen
32 
33const prescription2 = factory.createPrescription('Morphine', 5, true);
34prescription2.dispense(); // Output: Dispensing controlled substance: 5 units of Morphine

Observer Pattern

In a pharmacy system, there might be multiple components that need to react to changes in patient data. The Observer pattern can be used to notify these components when the data changes.

JavaScript

1class Patient {
2constructor(name) {
3  this.name = name;
4  this.observers = [];
5}
6 
7addObserver(observer) {
8  this.observers.push(observer);
9}
10 
11removeObserver(observer) {
12  this.observers = this.observers.filter(obs => obs !== observer);
13}
14 
15updateData(data) {
16  this.data = data;
17  this.notifyObservers();
18}
19 
20notifyObservers() {
21  this.observers.forEach(observer => observer.update(this));
22}
23}
24 
25class Doctor {
26update(patient) {
27  console.log(`Doctor notified: ${patient.name}'s data has been updated.`);
28}
29}
30 
31// Usage
32const patient = new Patient('John Doe');
33const doctor = new Doctor();
34 
35patient.addObserver(doctor);
36patient.updateData({ age: 30, weight: 75 }); // Output: Doctor notified: John Doe's data has been updated.

Strategy Pattern

The Strategy pattern can be used to implement different payment methods for pharmacy transactions.

JavaScript

1class PaymentStrategy {
2pay(amount) {}
3}
4 
5class CreditCardPayment extends PaymentStrategy {
6constructor(cardNumber, cvv) {
7  this.cardNumber = cardNumber;
8  this.cvv = cvv;
9}
10 
11pay(amount) {
12  console.log(`Paid ${amount} using credit card ${this.cardNumber}`);
13}
14}
15 
16class PayPalPayment extends PaymentStrategy {
17constructor(email) {
18  this.email = email;
19}
20 
21pay(amount) {
22  console.log(`Paid ${amount} using PayPal account ${this.email}`);
23}
24}
25 
26class PharmacyCheckout {
27constructor(paymentStrategy) {
28  this.paymentStrategy = paymentStrategy;
29}
30 
31setPaymentStrategy(strategy) {
32  this.paymentStrategy = strategy;
33}
34 
35checkout(amount) {
36  this.paymentStrategy.pay(amount);
37}
38}
39 
40// Usage
41const cardPayment = new CreditCardPayment('1234-5678-9012-3456', '123');
42const paypalPayment = new PayPalPayment('john.doe@example.com');
43 
44const checkout = new PharmacyCheckout(cardPayment);
45checkout.checkout(50); // Output: Paid 50 using credit card 1234-5678-9012-3456
46 
47checkout.setPaymentStrategy(paypalPayment);
48checkout.checkout(75); // Output: Paid 75 using PayPal account john.doe@example.com

Adapter Pattern

The Adapter pattern can be used to integrate third-party APIs or legacy systems into the pharmacy software.

JavaScript

1class ThirdPartyInventory {
2getStock(drug) {
3  // Simulate fetching stock from a third-party API
4  return Math.floor(Math.random() * 100);
5}
6}
7 
8class InventoryAdapter {
9constructor(thirdPartyInventory) {
10  this.thirdPartyInventory = thirdPartyInventory;
11}
12 
13checkStock(drug) {
14  const stock = this.thirdPartyInventory.getStock(drug);
15  console.log(`Stock for ${drug}: ${stock}`);
16}
17}
18 
19// Usage
20const thirdPartyInventory = new ThirdPartyInventory();
21const adapter = new InventoryAdapter(thirdPartyInventory);
22 
23adapter.checkStock('Aspirin'); // Output: Stock for Aspirin: (random number between 0 and 99)

What's Next?

In the next section, we will explore how design patterns can be applied to improve dental care software systems. Stay tuned!

By understanding and implementing these design patterns, you can create robust, scalable, and maintainable pharmacy software systems that meet the unique challenges of the healthcare industry.

🎭Design Patterns

Design Patterns in Pharmacy

Updated 2026-05-15

10 min read

Design Patterns in Pharmacy

Introduction

Concept

Common Design Patterns in Pharmacy Software

Singleton Pattern: Ensures that only one instance of a class is created and provides a global point of access to it.
Factory Method Pattern: Defines an interface for creating an object, but lets subclasses decide which class to instantiate.
Observer Pattern: A subject maintains a list of its dependents, called observers, and notifies them automatically of any state changes.
Strategy Pattern: Enables selecting an algorithm at runtime.
Adapter Pattern: Allows objects with incompatible interfaces to collaborate.

Examples

Let's dive into some practical examples of how these patterns can be applied in pharmacy software systems.

Singleton Pattern

In a pharmacy system, there might be a need for a single instance of a class that manages inventory data. The Singleton pattern ensures that only one such instance exists throughout the application.

JavaScript

1class InventoryManager {
2static instance;
3 
4constructor() {
5  if (InventoryManager.instance) {
6    return InventoryManager.instance;
7  }
8  this.inventory = {};
9  InventoryManager.instance = this;
10}
11 
12addItem(item, quantity) {
13  this.inventory[item] = quantity;
14}
15 
16getItemQuantity(item) {
17  return this.inventory[item];
18}
19}
20 
21// Usage
22const manager1 = new InventoryManager();
23manager1.addItem('Aspirin', 50);
24 
25const manager2 = new InventoryManager();
26console.log(manager2.getItemQuantity('Aspirin')); // Output: 50
27 
28console.log(manager1 === manager2); // Output: true

Factory Method Pattern

The Factory Method pattern can be used to create different types of prescription objects based on input parameters.

JavaScript

1class Prescription {
2constructor(drug, quantity) {
3  this.drug = drug;
4  this.quantity = quantity;
5}
6 
7dispense() {
8  console.log(`Dispensing ${this.quantity} units of ${this.drug}`);
9}
10}
11 
12class ControlledPrescription extends Prescription {
13dispense() {
14  console.log(`Dispensing controlled substance: ${this.quantity} units of ${this.drug}`);
15}
16}
17 
18class PrescriptionFactory {
19createPrescription(drug, quantity, isControlled) {
20  if (isControlled) {
21    return new ControlledPrescription(drug, quantity);
22  } else {
23    return new Prescription(drug, quantity);
24  }
25}
26}
27 
28// Usage
29const factory = new PrescriptionFactory();
30const prescription1 = factory.createPrescription('Ibuprofen', 20, false);
31prescription1.dispense(); // Output: Dispensing 20 units of Ibuprofen
32 
33const prescription2 = factory.createPrescription('Morphine', 5, true);
34prescription2.dispense(); // Output: Dispensing controlled substance: 5 units of Morphine

Observer Pattern

In a pharmacy system, there might be multiple components that need to react to changes in patient data. The Observer pattern can be used to notify these components when the data changes.

JavaScript

1class Patient {
2constructor(name) {
3  this.name = name;
4  this.observers = [];
5}
6 
7addObserver(observer) {
8  this.observers.push(observer);
9}
10 
11removeObserver(observer) {
12  this.observers = this.observers.filter(obs => obs !== observer);
13}
14 
15updateData(data) {
16  this.data = data;
17  this.notifyObservers();
18}
19 
20notifyObservers() {
21  this.observers.forEach(observer => observer.update(this));
22}
23}
24 
25class Doctor {
26update(patient) {
27  console.log(`Doctor notified: ${patient.name}'s data has been updated.`);
28}
29}
30 
31// Usage
32const patient = new Patient('John Doe');
33const doctor = new Doctor();
34 
35patient.addObserver(doctor);
36patient.updateData({ age: 30, weight: 75 }); // Output: Doctor notified: John Doe's data has been updated.

Strategy Pattern

The Strategy pattern can be used to implement different payment methods for pharmacy transactions.

JavaScript

1class PaymentStrategy {
2pay(amount) {}
3}
4 
5class CreditCardPayment extends PaymentStrategy {
6constructor(cardNumber, cvv) {
7  this.cardNumber = cardNumber;
8  this.cvv = cvv;
9}
10 
11pay(amount) {
12  console.log(`Paid ${amount} using credit card ${this.cardNumber}`);
13}
14}
15 
16class PayPalPayment extends PaymentStrategy {
17constructor(email) {
18  this.email = email;
19}
20 
21pay(amount) {
22  console.log(`Paid ${amount} using PayPal account ${this.email}`);
23}
24}
25 
26class PharmacyCheckout {
27constructor(paymentStrategy) {
28  this.paymentStrategy = paymentStrategy;
29}
30 
31setPaymentStrategy(strategy) {
32  this.paymentStrategy = strategy;
33}
34 
35checkout(amount) {
36  this.paymentStrategy.pay(amount);
37}
38}
39 
40// Usage
41const cardPayment = new CreditCardPayment('1234-5678-9012-3456', '123');
42const paypalPayment = new PayPalPayment('john.doe@example.com');
43 
44const checkout = new PharmacyCheckout(cardPayment);
45checkout.checkout(50); // Output: Paid 50 using credit card 1234-5678-9012-3456
46 
47checkout.setPaymentStrategy(paypalPayment);
48checkout.checkout(75); // Output: Paid 75 using PayPal account john.doe@example.com

Adapter Pattern

The Adapter pattern can be used to integrate third-party APIs or legacy systems into the pharmacy software.

JavaScript

1class ThirdPartyInventory {
2getStock(drug) {
3  // Simulate fetching stock from a third-party API
4  return Math.floor(Math.random() * 100);
5}
6}
7 
8class InventoryAdapter {
9constructor(thirdPartyInventory) {
10  this.thirdPartyInventory = thirdPartyInventory;
11}
12 
13checkStock(drug) {
14  const stock = this.thirdPartyInventory.getStock(drug);
15  console.log(`Stock for ${drug}: ${stock}`);
16}
17}
18 
19// Usage
20const thirdPartyInventory = new ThirdPartyInventory();
21const adapter = new InventoryAdapter(thirdPartyInventory);
22 
23adapter.checkStock('Aspirin'); // Output: Stock for Aspirin: (random number between 0 and 99)

What's Next?

In the next section, we will explore how design patterns can be applied to improve dental care software systems. Stay tuned!

By understanding and implementing these design patterns, you can create robust, scalable, and maintainable pharmacy software systems that meet the unique challenges of the healthcare industry.