iOS Contacts How to Fetch contact by phone Number

Had to make these changes for Swift 5:


lazy var contacts = {
            let contactStore = CNContactStore()
            let keysToFetch: [CNKeyDescriptor] = [
                CNContactFormatter.descriptorForRequiredKeys(for: .fullName),
                CNContactEmailAddressesKey as CNKeyDescriptor,
                CNContactPhoneNumbersKey as CNKeyDescriptor,
                CNContactImageDataAvailableKey as CNKeyDescriptor,
                CNContactThumbnailImageDataKey as CNKeyDescriptor]

            // Get all the containers
            var allContainers: [CNContainer] = []
            do {
                allContainers = try contactStore.containers(matching: nil)
            } catch {
                print("Error fetching containers")
            }

            var results: [CNContact] = []

            // Iterate all containers and append their contacts to our results array
            for container in allContainers {
                let fetchPredicate = CNContact.predicateForContactsInContainer(withIdentifier: container.identifier)

                do {
                    let containerResults = try     contactStore.unifiedContacts(matching: fetchPredicate, keysToFetch: keysToFetch)
                    results.append(contentsOf: containerResults)
                } catch {
                    print("Error fetching results for container")
                }
            }

            return results
        }()

And for the iteration and finding:

    func searchForContactUsingPhoneNumber(phoneNumber: String) -> [CNContact] {
         var result: [CNContact] = []

         for contact in contacts {
             if (!contact.phoneNumbers.isEmpty) {
                let phoneNumberToCompareAgainst = phoneNumber.components(separatedBy: NSCharacterSet.decimalDigits.inverted).joined(separator: "")
                 for phoneNumber in contact.phoneNumbers {
                     if let phoneNumberStruct = phoneNumber.value as? CNPhoneNumber {
                         let phoneNumberString = phoneNumberStruct.stringValue
                        let phoneNumberToCompare = phoneNumberString.components(separatedBy: NSCharacterSet.decimalDigits.inverted).joined(separator: "")
                         if phoneNumberToCompare == phoneNumberToCompareAgainst {
                             result.append(contact)
                         }
                     }
                 }
              }
         }

         return result
    }


SWIFT 4 UPDATE

1) Add to .plist

<key>NSContactsUsageDescription</key>
<string>Our application needs to your contacts</string>

2) Request Authorization if you don't have it

func requestAccess() {

    let store = CNContactStore()
    store.requestAccess(for: .contacts) { granted, error in
        guard granted else {
            DispatchQueue.main.async {
               self.presentSettingsActionSheet()
            }
            return
        }
    }
}

func presentSettingsActionSheet() {
    let alert = UIAlertController(title: "Permission to Contacts", message: "This app needs access to contacts in order to ...", preferredStyle: .actionSheet)
    alert.addAction(UIAlertAction(title: "Go to Settings", style: .default) { _ in
        let url = URL(string: UIApplicationOpenSettingsURLString)!
        UIApplication.shared.open(url)
    })
    alert.addAction(UIAlertAction(title: "Cancel", style: .cancel))
    present(alert, animated: true)
}

2) Check Authorization Status if you ask for it before

    if CNContactStore.authorizationStatus(for: .contacts) == .authorized {
        getContacts()

    }

3) Call Get Contacts

    var contacts = [CNContact]()

    func getContacts(){

    let contactStore = CNContactStore()
    let keys = [CNContactGivenNameKey, CNContactFamilyNameKey, CNContactPhoneNumbersKey, CNContactImageDataAvailableKey, CNContactThumbnailImageDataKey]
    let request = CNContactFetchRequest(keysToFetch: keys as [CNKeyDescriptor])
    request.sortOrder = CNContactSortOrder.givenName

    do {
        try contactStore.enumerateContacts(with: request) {
            (contact, stop) in
            self.contacts.append(contact)
        }
    }
    catch {
        print("unable to fetch contacts")
    }
}

4) THIS IS THE FUNCTION TO GET THE CONTACT NAME OR BY NUMBER

    func getNameFromContacts(number: String) -> String {
    var contactFetched : CNContact
    var contactName = ""
    if contacts.count > 0 {

        let numberToBeCompared = number.components(separatedBy:CharacterSet.decimalDigits.inverted).joined(separator: "")
        for c in contacts {
            for n in c.phoneNumbers {
                if let numberRetrived = n.value as? CNPhoneNumber {
                     let numberRetrivedFixed = numberRetrived.stringValue.components(separatedBy:CharacterSet.decimalDigits.inverted).joined(separator: "")
                    if numberRetrivedFixed.elementsEqual(numberToBeCompared){
                        contactName = c.givenName
                        // OR get the contact --> c
                 contactFetched = c

                    }
                }
            }
        }

        return contactName

    } else {
        return ""
    }
}

The problem with your implementation is that you access the address book in every search you are making.

If instead you will hold in-memory the address book content after the first access you will not reach this high CPU usage.

  1. First hold a lazy var in your controller that will hold the address book content:

    lazy var contacts: [CNContact] = {
        let contactStore = CNContactStore()
        let keysToFetch = [
            CNContactFormatter.descriptorForRequiredKeysForStyle(.FullName),
            CNContactEmailAddressesKey,
            CNContactPhoneNumbersKey,
            CNContactImageDataAvailableKey,
            CNContactThumbnailImageDataKey]
    
        // Get all the containers
        var allContainers: [CNContainer] = []
        do {
            allContainers = try contactStore.containersMatchingPredicate(nil)
        } catch {
            print("Error fetching containers")
        }
    
        var results: [CNContact] = []
    
        // Iterate all containers and append their contacts to our results array
        for container in allContainers {
            let fetchPredicate = CNContact.predicateForContactsInContainerWithIdentifier(container.identifier)
    
            do {
                 let containerResults = try     contactStore.unifiedContactsMatchingPredicate(fetchPredicate, keysToFetch: keysToFetch)
                results.appendContentsOf(containerResults)
            } catch {
                print("Error fetching results for container")
            }
        }
    
        return results
    }()
    
    1. Iterate through the in-memory array when you are looking for a contact with a specific phone number:

    .

       func searchForContactUsingPhoneNumber(phoneNumber: String) -> [CNContact] {
        var result: [CNContact] = []
    
        for contact in self.contacts {
            if (!contact.phoneNumbers.isEmpty) {
                let phoneNumberToCompareAgainst = phoneNumber.componentsSeparatedByCharactersInSet(NSCharacterSet.decimalDigitCharacterSet().invertedSet).joinWithSeparator("")
                for phoneNumber in contact.phoneNumbers {
                    if let phoneNumberStruct = phoneNumber.value as? CNPhoneNumber {
                        let phoneNumberString = phoneNumberStruct.stringValue
                        let phoneNumberToCompare = phoneNumberString.componentsSeparatedByCharactersInSet(NSCharacterSet.decimalDigitCharacterSet().invertedSet).joinWithSeparator("")
                        if phoneNumberToCompare == phoneNumberToCompareAgainst {
                            result.append(contact)
                        }
                    }
                }
             } 
        }
    
        return result
    }
    

I tested it with a very big address book, it works smoothly.

Here is the entire view controller patched together for reference.

import UIKit
import Contacts

class ViewController: UIViewController {

    lazy var contacts: [CNContact] = {
        let contactStore = CNContactStore()
        let keysToFetch = [
                CNContactFormatter.descriptorForRequiredKeysForStyle(.FullName),
                CNContactEmailAddressesKey,
                CNContactPhoneNumbersKey,
                CNContactImageDataAvailableKey,
                CNContactThumbnailImageDataKey]

        // Get all the containers
        var allContainers: [CNContainer] = []
        do {
            allContainers = try contactStore.containersMatchingPredicate(nil)
        } catch {
            print("Error fetching containers")
        }

        var results: [CNContact] = []

        // Iterate all containers and append their contacts to our results array
        for container in allContainers {
            let fetchPredicate = CNContact.predicateForContactsInContainerWithIdentifier(container.identifier)

            do {
                let containerResults = try contactStore.unifiedContactsMatchingPredicate(fetchPredicate, keysToFetch: keysToFetch)
                results.appendContentsOf(containerResults)
            } catch {
                print("Error fetching results for container")
            }
        }

        return results
    }()

    override func viewDidLoad() {
        super.viewDidLoad()
        // Do any additional setup after loading the view, typically from a nib.

        let contact = searchForContactUsingPhoneNumber("(555)564-8583")
        print(contact)
    }

    override func didReceiveMemoryWarning() {
        super.didReceiveMemoryWarning()
        // Dispose of any resources that can be recreated.
    }

    func searchForContactUsingPhoneNumber(phoneNumber: String) -> [CNContact] {

        var result: [CNContact] = []

        for contact in self.contacts {
            if (!contact.phoneNumbers.isEmpty) {
                let phoneNumberToCompareAgainst = phoneNumber.componentsSeparatedByCharactersInSet(NSCharacterSet.decimalDigitCharacterSet().invertedSet).joinWithSeparator("")
                for phoneNumber in contact.phoneNumbers {
                    if let phoneNumberStruct = phoneNumber.value as? CNPhoneNumber {
                        let phoneNumberString = phoneNumberStruct.stringValue
                        let phoneNumberToCompare = phoneNumberString.componentsSeparatedByCharactersInSet(NSCharacterSet.decimalDigitCharacterSet().invertedSet).joinWithSeparator("")
                        if phoneNumberToCompare == phoneNumberToCompareAgainst {
                            result.append(contact)
                        }
                    }
                }
            }
        }

        return result
    }
}

I used flohei's answer for the lazy var part.