14 KiB
14 KiB
iOS Naming Conventions Examples
Comprehensive examples of good and bad naming patterns in Swift.
Classes and Types
✅ Good Examples
// View Controllers
class PaymentViewController: UIViewController { }
class TransactionListViewController: UIViewController { }
class RefundConfirmationViewController: UIViewController { }
// ViewModels
class PaymentViewModel: BaseViewModel<PaymentState> { }
class StoresViewModel: BaseViewModel<StoresState> { }
class TransactionHistoryViewModel: BaseViewModel<TransactionHistoryState> { }
// Use Cases
protocol PaymentUseCase { }
class PaymentUseCaseImpl: PaymentUseCase { }
protocol RefundRequestUseCase { }
// Repositories
protocol PaymentRepository { }
class PaymentRepositoryImpl: PaymentRepository { }
// Models
struct Transaction { }
struct PaymentRequest { }
struct RefundRequest { }
// Enums
enum PaymentMethod { }
enum TransactionStatus { }
enum RefundRequestError: Error { }
❌ Bad Examples
// Too abbreviated
class PayVC: UIViewController { } // → PaymentViewController
class RefReqVM { } // → RefundRequestViewModel
class TrxRepo { } // → TransactionRepository
// Too generic
class Manager { } // → PaymentManager or specific purpose
class Helper { } // → ValidationHelper or specific purpose
class Util { } // → DateFormatter or specific utility
// Missing suffixes
class Payment { } // → PaymentViewModel or PaymentUseCase
class Transaction { } // If it's a ViewModel → TransactionViewModel
Variables and Properties
✅ Good Examples
class PaymentViewModel {
// State properties - descriptive
let paymentAmount = BehaviorRelay<String>(value: "")
let selectedPaymentMethod = BehaviorRelay<PaymentMethod?>(value: nil)
let transactionResult = BehaviorRelay<TransactionResult?>(value: nil)
// Boolean properties - with prefixes
let isProcessingPayment = BehaviorRelay<Bool>(value: false)
let hasNetworkConnection = BehaviorRelay<Bool>(value: true)
let shouldShowError = BehaviorRelay<Bool>(value: false)
let canSubmitPayment = BehaviorRelay<Bool>(value: false)
// Collections - plural
let transactions = BehaviorRelay<[Transaction]>(value: [])
let errorMessages = BehaviorRelay<[String]>(value: [])
let availablePaymentMethods = BehaviorRelay<[PaymentMethod]>(value: [])
// Dependencies - full names
private let paymentUseCase: PaymentUseCase
private let validationService: ValidationService
private let disposeBag = DisposeBag()
}
❌ Bad Examples
class PaymentViewModel {
// Abbreviated
let amt = BehaviorRelay<String>(value: "") // → paymentAmount
let pmtMethod = BehaviorRelay<PaymentMethod?>(value: nil) // → paymentMethod
let trxResult = BehaviorRelay<TransactionResult?>(value: nil) // → transactionResult
// Generic/meaningless
let flag = BehaviorRelay<Bool>(value: false) // → isProcessing
let data = BehaviorRelay<[Any]>(value: []) // → transactions
let temp = BehaviorRelay<String>(value: "") // → What is this?
// Boolean without prefix
let loading: Bool // → isLoading
let valid: Bool // → isValid
let enabled: Bool // → isEnabled
// Single letter
let x = 0 // → transactionCount
let a = amount // → paymentAmount
// Inconsistent abbreviations
let paymentUC: PaymentUseCase // → paymentUseCase
}
Functions and Methods
✅ Good Examples
class TransactionViewModel {
// Actions - verb-based, descriptive
func loadTransactions() { }
func refreshTransactionList() { }
func filterTransactionsByDate(from startDate: Date, to endDate: Date) { }
func processRefundRequest(for transactionId: String) { }
func validatePaymentAmount(_ amount: String) -> Bool { }
// Queries - return information
func getTransaction(by id: String) -> Transaction? { }
func calculateTotalAmount(for transactions: [Transaction]) -> Double { }
func hasUnprocessedTransactions() -> Bool { }
func isValidPaymentAmount(_ amount: String) -> Bool { }
// State handlers - clear purpose
func handlePaymentSuccess(_ result: PaymentResult) { }
func handlePaymentError(_ error: Error) { }
func handleNetworkConnectionLost() { }
// Setup/Configuration - clear intent
func setupUI() { }
func configureTableView() { }
func bindViewModel() { }
}
❌ Bad Examples
class TransactionViewModel {
// Too vague
func doSomething() { } // → processRefundRequest()
func process() { } // Process what? → processPayment()
func get() { } // Get what? → getTransactions()
func handle() { } // Handle what? → handleError()
func go() { } // Go where? → navigateToDetails()
// Noun-based instead of verb-based
func transaction() { } // → loadTransaction() or getTransaction()
func payment() { } // → processPayment()
// Abbreviated
func procPmt() { } // → processPayment()
func getTrx() { } // → getTransaction()
func valAmt(_ amt: String) { } // → validateAmount(_ amount: String)
}
IBOutlets
✅ Good Examples
class PaymentViewController: UIViewController {
// Text fields - with TextField suffix
@IBOutlet weak var paymentAmountTextField: UITextField!
@IBOutlet weak var merchantCodeTextField: UITextField!
@IBOutlet weak var notesTextField: UITextField!
// Labels - with Label suffix
@IBOutlet weak var currencyLabel: UILabel!
@IBOutlet weak var totalAmountLabel: UILabel!
@IBOutlet weak var errorMessageLabel: UILabel!
// Buttons - with Button suffix
@IBOutlet weak var confirmPaymentButton: UIButton!
@IBOutlet weak var cancelButton: UIButton!
@IBOutlet weak var submitButton: UIButton!
// Tables and collections - with TableView/CollectionView suffix
@IBOutlet weak var transactionTableView: UITableView!
@IBOutlet weak var storesCollectionView: UICollectionView!
// Other views - with type suffix
@IBOutlet weak var loadingIndicator: UIActivityIndicatorView!
@IBOutlet weak var headerView: UIView!
@IBOutlet weak var footerContainerView: UIView!
@IBOutlet weak var paymentMethodSegmentedControl: UISegmentedControl!
}
❌ Bad Examples
class PaymentViewController: UIViewController {
// Missing type suffix
@IBOutlet weak var amount: UITextField! // → amountTextField
@IBOutlet weak var currency: UILabel! // → currencyLabel
@IBOutlet weak var confirm: UIButton! // → confirmButton
// Abbreviated
@IBOutlet weak var lbl: UILabel! // → titleLabel
@IBOutlet weak var btn: UIButton! // → submitButton
@IBOutlet weak var txtField: UITextField! // → amountTextField
// Too generic
@IBOutlet weak var table: UITableView! // → transactionTableView
@IBOutlet weak var view: UIView! // → headerView
@IBOutlet weak var loading: UIActivityIndicatorView! // → loadingIndicator
}
Test Naming
✅ Good Examples
class PaymentViewModelTests: XCTestCase {
// Format: test[MethodName]_[Scenario]_[ExpectedResult]
func testProcessPayment_WithValidAmount_CompletesSuccessfully() { }
func testProcessPayment_WithEmptyAmount_ShowsValidationError() { }
func testProcessPayment_WithNetworkError_ShowsErrorState() { }
func testLoadTransactions_WithCachedData_ReturnsDataImmediately() { }
func testRefundRequest_WhenAmountExceedsTransaction_Fails() { }
func testValidateAmount_BelowMinimum_ReturnsFalse() { }
func testValidateAmount_AboveMaximum_ReturnsFalse() { }
func testValidateAmount_ValidRange_ReturnsTrue() { }
func testSubmitRefund_WithValidData_UpdatesStateToSuccess() { }
func testSubmitRefund_WithInvalidData_UpdatesStateToError() { }
}
❌ Bad Examples
class PaymentViewModelTests: XCTestCase {
func test1() { } // Meaningless number
func testPayment() { } // Too vague
func testError() { } // What error scenario?
func testStuff() { } // Meaningless
func test_payment_works() { } // snake_case (wrong)
}
Complete Class Examples
✅ Well-Named Class
class PaymentProcessingViewModel: BaseViewModel<PaymentState> {
// Dependencies - full, descriptive names
private let paymentUseCase: PaymentUseCase
private let validationService: ValidationService
private let disposeBag = DisposeBag()
// Input properties - clear, descriptive
let paymentAmount = BehaviorRelay<String>(value: "")
let selectedMerchantId = BehaviorRelay<String?>(value: nil)
let additionalNotes = BehaviorRelay<String>(value: "")
// State properties - boolean with prefixes
let isProcessingPayment = BehaviorRelay<Bool>(value: false)
let hasValidPaymentAmount = BehaviorRelay<Bool>(value: false)
let shouldEnableSubmitButton = BehaviorRelay<Bool>(value: false)
// Output properties - descriptive
let paymentResult = BehaviorRelay<PaymentResult?>(value: nil)
let errorMessage = BehaviorRelay<String?>(value: nil)
// Initializer - parameter names match properties
init(paymentUseCase: PaymentUseCase, validationService: ValidationService) {
self.paymentUseCase = paymentUseCase
self.validationService = validationService
super.init()
setupValidation()
}
// Methods - verb-based, descriptive
func processPaymentRequest() { }
func validatePaymentAmount() -> Bool { }
func clearPaymentForm() { }
func handlePaymentSuccess(_ result: PaymentResult) { }
func handlePaymentError(_ error: Error) { }
private func setupValidation() { }
private func updateSubmitButtonState() { }
}
❌ Poorly Named Class
class PaymentVM: BaseViewModel<PaymentState> { // Abbreviated
// Abbreviated dependencies
private let pmtUC: PaymentUseCase // → paymentUseCase
private let valService: ValidationService // → validationService
private let bag = DisposeBag() // → disposeBag
// Abbreviated/unclear properties
let amt = BehaviorRelay<String>(value: "") // → paymentAmount
let mid = BehaviorRelay<String?>(value: nil) // → merchantId
let notes = BehaviorRelay<String>(value: "") // Could be clearer
// Boolean without prefix
let processing = BehaviorRelay<Bool>(value: false) // → isProcessing
let valid = BehaviorRelay<Bool>(value: false) // → hasValidAmount
// Generic names
let result = BehaviorRelay<PaymentResult?>(value: nil) // → paymentResult
let error = BehaviorRelay<String?>(value: nil) // → errorMessage
// Abbreviated initializer
init(uc: PaymentUseCase, val: ValidationService) { // Bad parameter names
self.pmtUC = uc
self.valService = val
super.init()
}
// Vague method names
func process() { } // → processPaymentRequest()
func validate() -> Bool { } // → validatePaymentAmount()
func clear() { } // → clearPaymentForm()
func handle(_ r: PaymentResult) { } // → handlePaymentSuccess()
}
Refactoring Examples
Example: Refactoring Poor Names
Before (Bad)
class TrxVM: BaseViewModel<TrxState> {
let trxs = BehaviorRelay<[Trx]>(value: [])
let loading = BehaviorRelay<Bool>(value: false)
func getTrx(id: String) -> Trx? {
return trxs.value.first { $0.id == id }
}
func proc() {
loading.accept(true)
// Process transactions
}
}
After (Good)
class TransactionViewModel: BaseViewModel<TransactionState> {
let transactions = BehaviorRelay<[Transaction]>(value: [])
let isLoading = BehaviorRelay<Bool>(value: false)
func getTransaction(by id: String) -> Transaction? {
return transactions.value.first { $0.id == id }
}
func processTransactions() {
isLoading.accept(true)
// Process transactions
}
}
Changes Made:
TrxVM→TransactionViewModel(full names, proper suffix)trxs→transactions(no abbreviation, plural)loading→isLoading(boolean prefix)getTrx→getTransaction(full name, clear parameters)proc→processTransactions(verb-based, descriptive)
Quick Reference Checklist
Use this when reviewing naming:
## Naming Conventions Checklist
### Classes/Structs/Enums
- [ ] PascalCase
- [ ] Descriptive and meaningful
- [ ] Proper suffix (ViewModel, UseCase, etc.)
- [ ] No abbreviations
### Variables/Properties
- [ ] camelCase
- [ ] Meaningful names
- [ ] Booleans have is/has/should/can prefix
- [ ] Collections are plural
- [ ] No single letters (except loops)
- [ ] No abbreviations
### Functions/Methods
- [ ] camelCase
- [ ] Verb-based (actions) or get/has/is (queries)
- [ ] Descriptive of purpose
- [ ] Clear parameter names
### IBOutlets
- [ ] Include type suffix
- [ ] Descriptive of purpose
- [ ] camelCase
### General
- [ ] No generic names (Manager, Helper, Util)
- [ ] Consistent naming style
- [ ] Easy to understand without context