save email to safari local storage after login success

Question

I am trying to develop safari extension using swift safari services. The project is created from mac os and then safari extension. I am javascript developer but developing safari extension needed to use swift but I do not have any idea on how to save data in safari local storage. I looked at the following documentation but could not benefit from it

https://developer.apple.com/documentation/safariservices/safari_app_extensions

here is the code

import SafariServices


class SafariExtensionViewController: SFSafariExtensionViewController {


    @IBOutlet weak var passwordMessage: NSTextField!
    @IBOutlet weak var emailMessage: NSTextField!
    @IBOutlet weak var message: NSTextField!
    @IBOutlet weak var email: NSTextField!
    @IBOutlet weak var password: NSSecureTextField!
    static let shared = SafariExtensionViewController()
    override func viewDidLoad() {
        self.preferredContentSize = NSSize(width: 300, height: 250)
        message.stringValue = ""
        emailMessage.stringValue = ""
        passwordMessage.stringValue = ""
    }


    @IBAction func userLogin(_ sender: Any) {
        let providedEmailAddress = email.stringValue
        let providedPassword = password.stringValue
        let isEmailAddressValid = isValidEmailAddress(emailAddressString: providedEmailAddress)
        self.message.stringValue = ""
        emailMessage.stringValue = ""
        passwordMessage.stringValue = ""
        if isEmailAddressValid && providedPassword.count > 0 {
            let parameters = ["email": providedEmailAddress, "password": password.stringValue]
            let URI = URL(string: "https://api.production.navihq.com/auth/sign_in")
            let session = URLSession.shared
            var request = URLRequest(url: URI!)
            request.httpMethod = "POST"
            do {
                request.httpBody = try JSONSerialization.data(withJSONObject: parameters, options: .prettyPrinted)
            } catch let error {
                print(error.localizedDescription)
            }
            request.addValue("application/json", forHTTPHeaderField: "Content-Type")
            let task = session.dataTask(with: request as URLRequest, completionHandler: { data, response, error in

                guard error == nil else {
                    return
                }

                guard let data = data else {
                    return
                }

                do {
                    //create json object from data
                    if let json = try JSONSerialization.jsonObject(with: data, options: .mutableContainers) as? [String: Any] {
                        if let httpResponse = response as? HTTPURLResponse { 
                            if (httpResponse.statusCode >= 200 && httpResponse.statusCode < 300) {
                                self.message.stringValue = "Login Successful"
                                // i want to store the email in safari local storage here
                            } else {
                                self.message.stringValue = "Invalid Credentials"
                            }
                        }
                    }
                } catch let error {
                    print(error.localizedDescription)
                }
            })
            task.resume()
        } else {
            emailMessage.textColor = NSColor.red
            emailMessage.stringValue = "Invalid Email"
        }
    }

}

Not: I am not using IOS. I am using safariservices.

Answer 1

Think you should use Messaging capability between Safari app extension and injected script. For example, send message from injected script to app ext. when DOMContentLoaded triggered and send the answer to it with needed data (currently email) to set into local storage of the browser by injected JS.

Hope it helps!