UnstoppableDomainsResolution

Resolution is a library for interacting with blockchain domain names. It can be used to retrieve payment addresses and IPFS hashes for decentralized websites.

Resolution is primarily built and maintained by Unstoppable Domains.

Installing the library

Cocoa Pods

pod 'UnstoppableDomainsResolution', '~> 5.1.0'

Swift Package Manager

package.dependencies.append(
    .package(url: "https://github.com/unstoppabledomains/resolution-swift", from: "5.0.0")
)

Updating the library

Cocoa Pods

pod update UnstoppableDomainsResolution

Swift Package Manager

package.dependencies.append(
    .package(url: "https://github.com/unstoppabledomains/resolution-swift", from: "<latest version number>")
)

Usage

• Create an instance of the Resolution class
• Call any method of the Resolution class asyncronously

NOTE: make sure an instance of the Resolution class is not deallocated until the asyncronous call brings in the result. Your code is the only owner of the instance so keep it as long as you need it.

import UnstoppableDomainsResolution

guard let resolution = try? Resolution() else {
  print ("Init of Resolution instance with default parameters failed...")
  return
}

Customizing naming services

Version 0.3.0 introduced the Configurations struct that is used for configuring each connected naming service. Library supports three networks at the moment Ethereum, Polygon and Zilliqa. You can update each network separately.

let resolution = try Resolution(configs: Configurations(
        uns: UnsLocations = UnsLocations(
            layer1: NamingServiceConfig(
                providerUrl: "https://eth-mainnet.alchemyapi.io/v2/_BDuTLPgioYxULIE5cGq3wivWAJborcM",
                network: "mainnet"),
            layer2: NamingServiceConfig(
                providerUrl: "https://polygon-mainnet.g.alchemy.com/v2/bKmEKAC4HJUEDNlnoYITvXYuhrIshFsa",
                network: "polygon-mainnet"),
            zlayer: NamingServiceConfig(
                providerUrl: "https://api.zilliqa.com",
                network: "mainnet")
        )
);

resolution.addr(domain: "brad.crypto", ticker: "eth") { (result) in
    switch result {
    case .success(let returnValue):
        ethAddress = returnValue
        domainReceived.fulfill()
    case .failure(let error):
        XCTFail("Expected Eth Address, but got \(error)")
    }
}

Batch requesting of owners

Version 0.1.3 introduced the batchOwners(domains: _, completion: _ ) method which adds additional convenience when making multiple domain owner queries.

This method is only compatible with uns-based domains. Using this method with any other domain type will throw the error: ResolutionError.methodNotSupported.

As opposed to the single owner(domain: _, completion: _) method, this batch request will return an array of owners [String?]. If the the domain is not registered or its value is null, the corresponding array element of the response will be nil without throwing an error.

resolution.batchOwners(domains: ["brad.crypto", "homecakes.crypto"]) { result in
  switch result {
  case .success(let returnValue):
    // returnValue: [String: String?] = <map of domains to owner address>
    let domainOwner = returnValue
  case .failure(let error):
    XCTFail("Expected owner, but got \(error)")
  }
}

resolution.locations(domains: ["brad.crypto", "homecakes.crypto"]) { result in
  switch result {
  case .success(let returnValue):
    // returnValue: [String: String?] = <map of domains to domain locations>
    let locations = returnValue
  case .failure(let error):
    XCTFail("Expected owner, but got \(error)")
  }
}

Networking

Make sure your app has AppTransportSecurity settings to allow HTTP access to the https://main-rpc.linkpool.io domain.

Custom Networking Layer

By default, this library uses the native iOS networking API to connect to the internet. If you want the library to use your own networking layer instead, you must conform your networking layer to the NetworkingLayer protocol. This protocol requires only one method to be implemented: makeHttpPostRequest(url:, httpMethod:, httpHeaderContentType:, httpBody:, completion:). Using this method will bypass the default behavior and delegate the request to your own networking code.

For example, construct the Resolution instance like so:

guard let resolution = try? Resolution(networking: MyNetworkingApi) else {
  print ("Init of Resolution instance failed...")
  return
}

Possible Errors:

If the domain you are attempting to resolve is not registered or doesn't contain the information you are requesting, this framework will return a ResolutionError with the possible causes below. We advise creating customized errors in your app based on the return value of the error.

enum ResolutionError: Error {
    case unregisteredDomain
    case unsupportedDomain
    case recordNotFound
    case recordNotSupported
    case unsupportedNetwork
    case unspecifiedResolver
    case unknownError
    case proxyReaderNonInitialized
    case registryAddressIsNotProvided
    case inconsistentDomainArray
    case methodNotSupported
    case tooManyResponses
    case executionReverted
    case badRequestOrResponse
    case unsupportedServiceName
    case invalidDomainName
    case contractNotInitialized
    case reverseResolutionNotSpecified
}

Please see the Resolution-Swift Error Codes page for details of the specific error codes.

Contributions

Contributions to this library are more than welcome. The easiest way to contribute is through GitHub issues and pull requests.

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