How send Email using Gmail api in swift

Question

The Gmail Api has no clear documentation on how to do this, I have been trying with this but there are many things that are in the air.

I have sought external source

Answer 1

Here is the final solution I have finally make it work :

Podfile :

pod 'GoogleAPIClient/Gmail'

Sample Swift 5 code:

import Foundation
import GoogleAPIClient

class GMailManager {

    let service = GTLServiceGmail()

    func sendEmail() {

        guard let query = GTLQueryGmail.queryForUsersMessagesSend(with: nil) else {
            return
        }

        let gtlMessage = GTLGmailMessage()
        gtlMessage.raw = self.generateRawString()

        query.message = gtlMessage

        self.service.executeQuery(query, completionHandler: { (ticket, response, error) -> Void in
            print("ticket \(String(describing: ticket))")
            print("response \(String(describing: response))")
            print("error \(String(describing: error))")
        })
    }

    func generateRawString() -> String {

        let dateFormatter:DateFormatter = DateFormatter()
        dateFormatter.dateFormat = "EEE, dd MMM yyyy HH:mm:ss Z"; //RFC2822-Format
        let todayString:String = dateFormatter.string(from: NSDate() as Date)

        let rawMessage = "" +
            "Date: \(todayString)\r\n" +
            "From: <mail>\r\n" +
            "To: username <mail>\r\n" +
            "Subject: Test send email\r\n\r\n" +
            "Test body"

        print("message \(rawMessage)")

        return GTLEncodeWebSafeBase64(rawMessage.data(using: String.Encoding.utf8))
    }
}

Answer 2

I found the solution

class func sendEmail() {

        var gtlMessage = GTLGmailMessage()
        gtlMessage.raw = self.generateRawString()

        let appd = UIApplication.sharedApplication().delegate as! AppDelegate
        let query = GTLQueryGmail.queryForUsersMessagesSendWithUploadParameters(nil)
        query.message = gtlMessage

        appd.service.executeQuery(query, completionHandler: { (ticket, response, error) -> Void in
            println("ticket \(ticket)")
            println("response \(response)")
            println("error \(error)")
        })
    }

    class func generateRawString() -> String {

        var dateFormatter:NSDateFormatter = NSDateFormatter()
        dateFormatter.dateFormat = "EEE, dd MMM yyyy HH:mm:ss Z"; //RFC2822-Format
        var todayString:String = dateFormatter.stringFromDate(NSDate())

        var rawMessage = "" +
            "Date: \(todayString)\r\n" +
            "From: <mail>\r\n" +
            "To: username <mail>\r\n" +
            "Subject: Test send email\r\n\r\n" +
            "Test body"

        println("message \(rawMessage)")

        return GTLEncodeWebSafeBase64(rawMessage.dataUsingEncoding(NSUTF8StringEncoding))
    }

Answer 3

According to Google API documentation(https://developers.google.com/gmail/api/guides/sending), we can know there are have two ways can help you send message success(draft.send, message.send). without a doubt, both of them use api are different, but the result is the same. As you give one of the above way can got that, we just call it message.send. With another way is draft.send, so we should upload "UploadParameters" to Gmail draft, after we upload success, we can get some message about gmail draft. At last, we should send mail content, when we send success, the draft message will automatic delete. Code goes be as follows:

func postEmailMessageRequest(model: MEMailMessageModel, request: CompletionRequest) {

        let uploadParameters = GTLUploadParameters()
        uploadParameters.data = model.snippet.dataUsingEncoding(NSUTF8StringEncoding)
        uploadParameters.MIMEType = model.mimeType!

        let query = GTLQueryGmail.queryForUsersDraftsCreateWithUploadParameters(uploadParameters) as! GTLQueryProtocol!
        service.executeQuery(query) { (ticket : GTLServiceTicket!, messages : AnyObject!, error : NSError?) -> Void in
            if error == nil {
                let messages = (messages as! GTLGmailDraft)
                messages.message.threadId = model.threadID
                self.sendMailRequest(messages, model: model, request: request)
            } else {
                request(status: false, result: "upload success")
            }
        }
    }

    func sendMailRequest(draft: GTLGmailDraft, model: MEMailMessageModel, request: CompletionRequest) {

        let query = GTLQueryGmail.queryForUsersDraftsSendWithUploadParameters(nil) as! GTLQueryGmail
        draft.message.raw = self.generateRawString(model)
        query.draft = draft

        self.service.executeQuery(query, completionHandler: { (ticket, response, error) -> Void in
            if error == nil {
                request(status: true, result: "send success") // after this, the draft will be delete
            } else {
                request(status: false, result: "send failure")
            }
        })
    }

    func generateRawString(model: MEMailMessageModel) -> String {
        let date = MEMailMessagelFormatUtil.coverDateFromDate(NSDate(), dateFormat: "EEE, dd MMM yyyy HH:mm:ss Z")! // get current date

        var fromEamil = ""
        if let str = NSUserDefaults.standardUserDefaults().valueForKey("userEmail") as? String {
            fromEamil = str
        }

        var rawMessage = ""
        if model.isReply { // how to reply, but how to reply the email is another question.
            rawMessage = "" + "In-Reply-To: \(model.messageID!)\r\n"
            if let references = model.references {
                rawMessage += "References: \(references) \(model.messageID!)\r\n"
            } else {
                rawMessage += "References: \(model.messageID!)\r\n"
            }
        }

        rawMessage += "Date: \(date)\r\n" +
            "From: <\(fromEamil)>\r\n" +
            "To: \(model.toName!) <\(model.toMail)>\r\n" +
            "Subject: \(model.subject) \r\n\r\n" + "\(model.snippet)"

        return GTLEncodeWebSafeBase64(rawMessage.dataUsingEncoding(NSUTF8StringEncoding))
    }

Answer 4

If your goal is to send an email I suggest using the MailCore library for iOS. In the documentation there are examples just in Objective-c but it is compatible with Swift

This is an example of how to send an email with MailCore and Swift:

var smtpSession = MCOSMTPSession()
smtpSession.hostname = "smtp.gmail.com"
smtpSession.username = "matt@gmail.com"
smtpSession.password = "xxxxxxxxxxxxxxxx"
smtpSession.port = 465
smtpSession.authType = MCOAuthType.SASLPlain
smtpSession.connectionType = MCOConnectionType.TLS
smtpSession.connectionLogger = {(connectionID, type, data) in
    if data != nil {
        if let string = NSString(data: data, encoding: NSUTF8StringEncoding){
            NSLog("Connectionlogger: \(string)")
        }
    }
}

var builder = MCOMessageBuilder()
builder.header.to = [MCOAddress(displayName: "Rool", mailbox: "itsrool@gmail.com")]
builder.header.from = MCOAddress(displayName: "Matt R", mailbox: "matt@gmail.com")
builder.header.subject = "My message"
builder.htmlBody = "Yo Rool, this is a test message!"

let rfc822Data = builder.data()
let sendOperation = smtpSession.sendOperationWithData(rfc822Data)
sendOperation.start { (error) -> Void in
    if (error != nil) {
        NSLog("Error sending email: \(error)")
    } else {
        NSLog("Successfully sent email!")
    }
}