pjwelcome

class MainActivity : AppCompatActivity() {

    private var mNfcAdapter: NfcAdapter? = null

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_main)
        mNfcAdapter = NfcAdapter.getDefaultAdapter(this)
    }

pjwelcome

private fun writeMessageToTag(nfcMessage: NdefMessage, tag: Tag?): Boolean {

        try {
            val nDefTag = Ndef.get(tag)

            nDefTag?.let {
                it.connect()
                if (it.maxSize < nfcMessage.toByteArray().size) {
                    //Message to large to write to NFC tag
                    return false

pjwelcome

 fun createNFCMessage(payload: String, intent: Intent?) : Boolean {

        val pathPrefix = "peterjohnwelcome.com:nfcapp"
        val nfcRecord = NdefRecord(NdefRecord.TNF_EXTERNAL_TYPE, pathPrefix.toByteArray(), ByteArray(0), payload.toByteArray())
        val nfcMessage = NdefMessage(arrayOf(nfcRecord))
        intent?.let {
            val tag = it.getParcelableExtra<Tag>(NfcAdapter.EXTRA_TAG)
            return  writeMessageToTag(nfcMessage, tag)
        }
        return false

pjwelcome

 fun disableNFCInForeground(nfcAdapter: NfcAdapter,activity: Activity) {
        nfcAdapter.disableForegroundDispatch(activity)
 }

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fun <T>enableNFCInForeground(nfcAdapter: NfcAdapter, activity: Activity, classType : Class<T>) {
        val pendingIntent = PendingIntent.getActivity(activity, 0,
                Intent(activity,classType).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP), 0)
        val nfcIntentFilter = IntentFilter(NfcAdapter.ACTION_NDEF_DISCOVERED)
        val filters = arrayOf(nfcIntentFilter)

        val TechLists = arrayOf(arrayOf(Ndef::class.java.name), arrayOf(NdefFormatable::class.java.name))

        nfcAdapter.enableForegroundDispatch(activity, pendingIntent, filters, TechLists)
 }

pjwelcome

 private fun getNDefMessages(intent: Intent): Array<NdefMessage> {

        val rawMessage = intent.getParcelableArrayExtra(NfcAdapter.EXTRA_NDEF_MESSAGES)
        rawMessage?.let {
            return rawMessage.map {
                it as NdefMessage
            }.toTypedArray()
        }
        // Unknown tag type
        val empty = byteArrayOf()

pjwelcome

fun retrieveNFCMessage(intent: Intent?): String {
        intent?.let {
            if (NfcAdapter.ACTION_NDEF_DISCOVERED == intent.action) {
                val nDefMessages = getNDefMessages(intent)
                nDefMessages[0].records?.let {
                    it.forEach {
                        it?.payload.let {
                            it?.let {
                                return String(it)

pjwelcome

//: Playground - noun: a place where people can play

import UIKit
import XCTest

struct Product {
    var name: String
    var price : Double
}

pjwelcome

struct Product {
    var name: String
    var price : Double
}

pjwelcome

protocol ProductsRepository {
    
    func fetchProducts() -> [Product]
}