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Overview

This guide covers balance operations including balance retrieval, Wei to ETH conversion, and balance formatting with the Dynamic Swift SDK.

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Prerequisites

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Balance Operations

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Get Latest Balance and Convert to ETH

// Get latest balance (sample app usage)
do {
    let balanceWei = try await ethereumWallet.getBalance(.Latest)
    print("💰 Balance in Wei: \(balanceWei)")
    
    // Convert Wei to Ether (sample app conversion pattern)
    guard let etherValue = Double(String(balanceWei)) else {
        print("❌ Failed to convert balance to double")
        return
    }
    let etherInDecimals = etherValue / pow(10.0, 18.0)
    let balanceEth = String(format: "%.6f", etherInDecimals)
    
    print("💰 Balance in ETH: \(balanceEth)")
} catch {
    print("❌ Failed to fetch balance: \(error)")
}

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Get Wallet Balance

// Get latest balance
do {
    let balanceWei = try await ethereumWallet.getBalance(.Latest)

    // Convert Wei to Ether
    let etherValue = Double(String(balanceWei)) ?? 0.0
    let balanceEth = etherValue / pow(10.0, 18.0)

    print("Balance: \(String(format: "%.6f", balanceEth)) ETH")
} catch {
    print("Failed to get balance: \(error)")
}

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Balance Conversion Utilities

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Wei to ETH Conversion

// Convert Wei to ETH with proper formatting
func weiToEth(_ wei: BigUInt, decimals: Int = 6) -> String {
    let etherValue = Double(String(wei)) ?? 0.0
    let ethValue = etherValue / pow(10.0, 18.0)
    return String(format: "%.\(decimals)f", ethValue)
}

// Usage
let balanceWei = try await ethereumWallet.getBalance(.Latest)
let balanceEth = weiToEth(balanceWei)
print("Balance: \(balanceEth) ETH")

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ETH to Wei Conversion

// Convert ETH to Wei
func ethToWei(_ eth: Double) -> BigUInt {
    let weiValue = eth * pow(10.0, 18.0)
    return BigUInt(weiValue)
}

// Usage
let ethAmount = 1.5
let weiAmount = ethToWei(ethAmount)
print("\(ethAmount) ETH = \(weiAmount) Wei")

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Gwei Conversions

// Convert Wei to Gwei
func weiToGwei(_ wei: BigUInt) -> Double {
    let gweiValue = Double(String(wei)) ?? 0.0
    return gweiValue / pow(10.0, 9.0) // 1 Gwei = 10^9 Wei
}

// Convert Gwei to Wei
func gweiToWei(_ gwei: Double) -> BigUInt {
    let weiValue = gwei * pow(10.0, 9.0)
    return BigUInt(weiValue)
}

// Usage
let gasPriceWei = try await networkClient.eth_gasPriceBigInt()
let gasPriceGwei = weiToGwei(gasPriceWei)
print("Gas Price: \(String(format: "%.2f", gasPriceGwei)) Gwei")

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Balance Formatting

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Format Balance for Display

// Format balance with appropriate units
func formatBalance(_ wei: BigUInt) -> String {
    let ethValue = Double(String(wei)) ?? 0.0
    let eth = ethValue / pow(10.0, 18.0)
    
    if eth >= 1.0 {
        return String(format: "%.4f ETH", eth)
    } else if eth >= 0.001 {
        return String(format: "%.6f ETH", eth)
    } else {
        let gwei = ethValue / pow(10.0, 9.0)
        return String(format: "%.2f Gwei", gwei)
    }
}

// Usage
let balanceWei = try await ethereumWallet.getBalance(.Latest)
let formattedBalance = formatBalance(balanceWei)
print("Balance: \(formattedBalance)")

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Human-Readable Balance

// Create human-readable balance display
func humanReadableBalance(_ wei: BigUInt) -> String {
    let ethValue = Double(String(wei)) ?? 0.0
    let eth = ethValue / pow(10.0, 18.0)
    
    switch eth {
    case let x where x >= 1000:
        return String(format: "%.2f ETH", x)
    case let x where x >= 1:
        return String(format: "%.4f ETH", x)
    case let x where x >= 0.01:
        return String(format: "%.6f ETH", x)
    case let x where x >= 0.000001:
        let gwei = ethValue / pow(10.0, 9.0)
        return String(format: "%.2f Gwei", gwei)
    default:
        return "\(wei) Wei"
    }
}

// Usage
let balanceWei = try await ethereumWallet.getBalance(.Latest)
let humanBalance = humanReadableBalance(balanceWei)
print("Balance: \(humanBalance)")

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Balance Monitoring

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Real-Time Balance Updates

// Monitor balance changes
class BalanceMonitor {
    private var lastBalance: BigUInt = BigUInt(0)
    private let wallet: EthereumWallet
    
    init(wallet: EthereumWallet) {
        self.wallet = wallet
    }
    
    func startMonitoring() async {
        while true {
            do {
                let currentBalance = try await wallet.getBalance(.Latest)
                
                if currentBalance != lastBalance {
                    let change = currentBalance > lastBalance ? "+" : "-"
                    let difference = currentBalance > lastBalance ? 
                        currentBalance - lastBalance : 
                        lastBalance - currentBalance
                    
                    print("💰 Balance changed: \(change)\(weiToEth(difference)) ETH")
                    print("💰 New balance: \(weiToEth(currentBalance)) ETH")
                    
                    lastBalance = currentBalance
                }
                
                // Check every 30 seconds
                try await Task.sleep(nanoseconds: 30_000_000_000)
            } catch {
                print("❌ Failed to check balance: \(error)")
                break
            }
        }
    }
}

// Usage
let monitor = BalanceMonitor(wallet: ethereumWallet)
await monitor.startMonitoring()

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Balance History Tracking

// Track balance history
struct BalanceEntry {
    let timestamp: Date
    let balanceWei: BigUInt
    let balanceEth: String
}

class BalanceTracker {
    private var balanceHistory: [BalanceEntry] = []
    
    func addBalanceEntry(_ wei: BigUInt) {
        let entry = BalanceEntry(
            timestamp: Date(),
            balanceWei: wei,
            balanceEth: weiToEth(wei)
        )
        balanceHistory.append(entry)
    }
    
    func getBalanceHistory() -> [BalanceEntry] {
        return balanceHistory
    }
    
    func getBalanceChange(duration: TimeInterval) -> BigUInt? {
        let cutoffDate = Date().addingTimeInterval(-duration)
        let recentEntries = balanceHistory.filter { $0.timestamp >= cutoffDate }
        
        guard let oldest = recentEntries.first,
              let newest = recentEntries.last else {
            return nil
        }
        
        return newest.balanceWei - oldest.balanceWei
    }
}

// Usage
let tracker = BalanceTracker()
let balanceWei = try await ethereumWallet.getBalance(.Latest)
tracker.addBalanceEntry(balanceWei)

// Check balance change in last hour
if let change = tracker.getBalanceChange(duration: 3600) {
    print("Balance change in last hour: \(weiToEth(change)) ETH")
}

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Balance Validation

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Check Sufficient Balance

// Check if wallet has sufficient balance for transaction
func hasSufficientBalance(
    wallet: EthereumWallet,
    amount: BigUInt,
    gasPrice: BigUInt,
    gasLimit: BigUInt
) async throws -> Bool {
    let balance = try await wallet.getBalance(.Latest)
    let totalCost = amount + (gasPrice * gasLimit)
    return balance >= totalCost
}

// Usage
let transactionAmount = BigUInt(1000000000000000000) // 1 ETH
let gasPrice = try await networkClient.eth_gasPriceBigInt()
let gasLimit = BigUInt(21_000)

do {
    let sufficient = try await hasSufficientBalance(
        wallet: ethereumWallet,
        amount: transactionAmount,
        gasPrice: gasPrice,
        gasLimit: gasLimit
    )
    
    if sufficient {
        print("✅ Sufficient balance for transaction")
    } else {
        print("❌ Insufficient balance for transaction")
    }
} catch {
    print("❌ Failed to check balance: \(error)")
}

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Best Practices

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1. Use Consistent Conversion Patterns

// Standard conversion pattern
let etherValue = Double(String(balanceWei)) ?? 0.0
let balanceEth = etherValue / pow(10.0, 18.0)
let formattedBalance = String(format: "%.6f", balanceEth)

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2. Handle Large Numbers Properly

// Use BigUInt for large numbers to avoid overflow
let balanceWei: BigUInt = try await ethereumWallet.getBalance(.Latest)
let amountWei: BigUInt = BigUInt(1000000000000000000) // 1 ETH

// Safe arithmetic with BigUInt
let total = balanceWei + amountWei

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3. Format for User Display

// Always format balances for user-friendly display
let rawBalance = try await ethereumWallet.getBalance(.Latest)
let displayBalance = humanReadableBalance(rawBalance)
print("Your balance: \(displayBalance)")

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4. Monitor Balance Changes

// Monitor balance for important changes
let initialBalance = try await ethereumWallet.getBalance(.Latest)
// ... perform transaction ...
let finalBalance = try await ethereumWallet.getBalance(.Latest)

if finalBalance != initialBalance {
    let change = finalBalance > initialBalance ? 
        finalBalance - initialBalance : 
        initialBalance - finalBalance
    print("Balance changed by: \(weiToEth(change)) ETH")
}

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Error Handling

do {
    let balance = try await ethereumWallet.getBalance(.Latest)
} catch {
    if let nsError = error as NSError? {
        switch nsError.code {
        case 6001:
            print("Network connection failed")
        case 6002:
            print("Invalid wallet address")
        case 6003:
            print("Balance query timeout")
        default:
            print("Balance error: \(error)")
        }
    }
}

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Next Steps

After mastering balance operations, you can: