Error Handling

The Flow Wallet Kit for iOS implements comprehensive error handling to help developers handle and debug issues effectively.

Flow Wallet Kit provides comprehensive error handling through the FWKError enum. This documentation covers all possible errors you might encounter while using the SDK and how to handle them.

Error Categories

General Errors

Error	Description	Common Causes
`noImplement`	Feature not implemented	Attempting to use planned but unavailable functionality
`emptyKeychain`	No keys in keychain	Missing or deleted keychain entries
`emptyKey`	Invalid key data	Corrupted or missing key data
`emptySignKey`	Missing signing key	Attempting to sign without setting up a key

Cryptographic Errors

Error	Description	Common Causes
`unsupportHashAlgorithm`	Unsupported hash algorithm	Using non-supported hashing method
`unsupportSignatureAlgorithm`	Unsupported signature algorithm	Using non-supported signing method
`initChaChapolyFailed`	ChaCha20-Poly1305 initialization failed	Encryption setup issues
`initHDWalletFailed`	HD wallet initialization failed	Invalid entropy or seed phrase
`initPrivateKeyFailed`	Private key initialization failed	Invalid key data
`restoreWalletFailed`	Wallet restoration failed	Corrupted backup data
`invaildSignatureAlgorithm`	Invalid signature algorithm	Unknown signing algorithm specified
`invaildEVMAddress`	Invalid EVM address	Malformed Ethereum address

Authentication Errors

Error	Description	Common Causes
`invaildPassword`	Invalid password	Wrong password for decryption
`invaildPrivateKey`	Invalid private key format	Malformed private key data
`invaildKeyStoreJSON`	Invalid KeyStore JSON	Malformed or incomplete KeyStore file
`invaildKeyStorePassword`	Invalid KeyStore password	Wrong password for KeyStore
`signError`	Signing operation failed	Transaction signing issues
`initPublicKeyFailed`	Public key initialization failed	Key derivation issues
`failedPassSecurityCheck`	Security check failed	Failed security validation

Network Errors

Error	Description	Common Causes
`incorrectKeyIndexerURL`	Invalid key indexer URL	Malformed service URL
`keyIndexerRequestFailed`	Key indexer request failed	Network or service issues
`decodeKeyIndexerFailed`	Key indexer response decode failed	Invalid response format

Storage Errors

Error	Description	Common Causes
`loadCacheFailed`	Cache loading failed	Corrupted cache data
`invaildWalletType`	Invalid wallet type	Unsupported operation for wallet type
`cacheDecodeFailed`	Cache decode failed	Invalid cache data format
`emptyCreatedAddress`	Empty created address	Account creation failure

Error Handling Example

Here's how to properly handle errors in your code:

do {
    let wallet = try await FlowWallet.create()
    try await wallet.sign(transaction)
} catch FWKError.emptySignKey {
    // Handle missing signing key
    print("No signing key available")
} catch FWKError.signError {
    // Handle signing failure
    print("Failed to sign transaction")
} catch {
    // Handle other errors
    print("Unexpected error: \(error)")
}

Error Codes

Each error case has a unique error code that can be accessed through the errorCode property. The error codes are based on the order of declaration in the FWKError enum.

let error = FWKError.emptySignKey
print(error.description) // Prints: "FWKError Code: 3-emptySignKey"

Best Practices

Always handle specific errors: Catch and handle specific error cases that your application needs to respond to differently.
Provide user feedback: Convert technical errors into user-friendly messages.
Log errors: Use the error codes and descriptions for logging and debugging.
Security considerations: Never expose sensitive information in error messages.

Common Error Resolution

Here are some common approaches to resolving specific errors:

emptyKeychain: Ensure proper key initialization and storage
initHDWalletFailed: Verify seed phrase or entropy input
signError: Check key permissions and transaction format
keyIndexerRequestFailed: Verify network connection and service status
loadCacheFailed: Clear cache and retry operation

Error Handling

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