Big thanks to Paulw11 for helping me solve this issue. I've added the full code here for easy reuse:
Class:
import UIKit
import MessageUI
struct Feedback {
let recipients: [String]
let subject: String
let body: String
let footer: String
}
class FeedbackManager: NSObject, MFMailComposeViewControllerDelegate {
private var feedback: Feedback
private var completion: ((Result<MFMailComposeResult,Error>)->Void)?
override init() {
fatalError("Use FeedbackManager(feedback:)")
}
init?(feedback: Feedback) {
guard MFMailComposeViewController.canSendMail() else {
return nil
}
self.feedback = feedback
}
func send(on viewController: UIViewController, completion:(@escaping(Result<MFMailComposeResult,Error>)->Void)) {
let mailVC = MFMailComposeViewController()
self.completion = completion
mailVC.mailComposeDelegate = self
mailVC.setToRecipients(feedback.recipients)
mailVC.setSubject(feedback.subject)
mailVC.setMessageBody("<p>\(feedback.body)<br><br><br><br><br>\(feedback.footer)</p>", isHTML: true)
viewController.present(mailVC, animated:true)
}
func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
if let error = error {
completion?(.failure(error))
controller.dismiss(animated: true)
} else {
completion?(.success(result))
controller.dismiss(animated: true)
}
}
}
In View Controller:
Add Variable:
var feedbackManager: FeedbackManager?
Use:
let feedback = Feedback(recipients: "String", subject: "String", body: "Body", footer: "String")
if let feedManager = FeedbackManager(feedback: feedback) {
self.feedbackManager = feedManager
self.feedbackManager?.send(on: self) { [weak self] result in
switch result {
case .failure(let error):
print("error: ", error.localizedDescription)
// Do something with the error
case .success(let mailResult):
print("Success")
// Do something with the result
}
self?.feedbackManager = nil
}
} else { // Cant Send Email: // Added UI Alert:
let failedMenu = UIAlertController(title: "String", message: nil, preferredStyle: .alert)
let okAlert = UIAlertAction(title: "String", style: .default)
failedMenu.addAction(okAlert)
present(failedMenu, animated: true)
}
I'm trying to make a class that handles initializing a MFMailComposeViewController to send an email inside of the app.
I'm having issues making it work. Well, rather making it not crash if it doesn't work.
class:
import UIKit
import MessageUI
struct Feedback {
let recipients = "String"
let subject: String
let body: String
}
class FeedbackManager: MFMailComposeViewController, MFMailComposeViewControllerDelegate {
func sendEmail(feedback: Feedback) {
if MFMailComposeViewController.canSendMail() {
self.mailComposeDelegate = self
self.setToRecipients([feedback.recipients])
self.setSubject("Feedback: \(feedback.subject)")
self.setMessageBody("<p>\(feedback.body)</p>", isHTML: true)
} else {
print("else:")
mailFailed()
}
}
func mailFailed() {
print("mailFailed():")
let failedMenu = UIAlertController(title: "Please Email Me!", message: nil, preferredStyle: .alert)
let okAlert = UIAlertAction(title: "Ok!", style: .default)
failedMenu.addAction(okAlert)
self.present(failedMenu, animated: true, completion: nil)
}
func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
controller.dismiss(animated: true)
}
}
And then calling it from a different view controller:
let feedbackManager = FeedbackManager()
feedbackManager.sendEmail(feedback: Feedback(subject: "String", body: "String"))
self.present(feedbackManager, animated: true, completion: nil)
tableView.deselectRow(at: indexPath, animated: true)
The above works just fine if MFMailComposeViewController.canSendMail() == true. The problem I'm facing is that if canSendMail() is not true, then the class obviously cant initialize and crashes. Which makes sense.
Error:
Unable to initialize due to + [MFMailComposeViewController canSendMail] returns NO.
I'm not sure where to go from here on how to get this working. I've tried changing FeedbackManager from MFMailComposeViewController to a UIViewController. And that seems to work but because it's adding a view on the stack, it's causing a weird graphical display.
The other thing I could do is import MessageUI, and conform to MFMailComposeViewController for every controller I want to be able to send an email from. So that I can check against canSendMail() before trying to initialize FeedbackManager(). But that also doesn't seem like the best answer.
How else can I get this working?
EDIT: I've gotten the code to work with this however, there is an ugly transition with the addition of the view onto the stack before it presents the MFMailComposeViewController.
class FeedbackManager: UIViewController, MFMailComposeViewControllerDelegate {
func sendEmail(feedback: Feedback, presentingViewController: UIViewController) -> UIViewController {
if MFMailComposeViewController.canSendMail() {
let mail = MFMailComposeViewController()
mail.mailComposeDelegate = self
mail.setToRecipients([feedback.recipients])
mail.setSubject("Feedback: \(feedback.subject)")
mail.setMessageBody("<p>\(feedback.body)</p>", isHTML: true)
present(mail, animated: true)
return self
} else {
print("else:")
return mailFailed(presentingViewController: presentingViewController)
}
}
func mailFailed(presentingViewController: UIViewController) -> UIViewController {
print("mailFailed():")
let failedMenu = UIAlertController(title: "Please Email Me!", message: nil, preferredStyle: .alert)
let okAlert = UIAlertAction(title: "Ok!", style: .default)
failedMenu.addAction(okAlert)
return failedMenu
}
func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
controller.dismiss(animated: true)
self.dismiss(animated: false)
}
}
Subclassing MFMailComposeViewController is the wrong approach. This class is intended to be used "as-is". You can build a wrapper class if you like:
struct Feedback {
let recipients = "String"
let subject: String
let body: String
}
class FeedbackManager: NSObject, MFMailComposeViewControllerDelegate {
private var feedback: Feedback
private var completion: ((Result<MFMailComposeResult,Error>)->Void)?
override init() {
fatalError("Use FeedbackManager(feedback:)")
}
init?(feedback: Feedback) {
guard MFMailComposeViewController.canSendMail() else {
return nil
}
self.feedback = feedback
}
func send(on viewController: UIViewController, completion:(@escaping(Result<MFMailComposeResult,Error>)->Void)) {
let mailVC = MFMailComposeViewController()
self.completion = completion
mailVC.mailComposeDelegate = self
mailVC.setToRecipients([feedback.recipients])
mailVC.setSubject("Feedback: \(feedback.subject)")
mailVC.setMessageBody("<p>\(feedback.body)</p>", isHTML: true)
viewController.present(mailVC, animated:true)
}
func mailComposeController(_ controller: MFMailComposeViewController, didFinishWith result: MFMailComposeResult, error: Error?) {
if let error = error {
completion?(.failure(error))
} else {
completion?(.success(result))
}
}
}
And then to use it from a view controller:
let feedback = Feedback(subject: "String", body: "Body")
if let feedbackMgr = FeedbackManager(feedback: feedback) {
self.feedbackManager = feedbackMgr
feedback.send(on: self) { [weak self], result in
switch result {
case .failure(let error):
// Do something with the error
case .success(let mailResult):
// Do something with the result
}
self.feedbackManager = nil
}
} else {
// Can't send email
}
You will need to hold a strong reference to the FeedbackManager in a property otherwise it will be released as soon as the containing function exits. My code above refers to a property
var feedbackManager: FeedbackManager?
While this will work, a better UX is if you check canSendMail directly and disable/hide the UI component that allows them to send feedback