#11 setOnNdefDiscoveredListener callback is not invoked on main threa…

…d in iOS

README.md

@@ -25,9 +25,9 @@ tns plugin add nativescript-nfc
 ## iOS Setup
 iOS requires you to enable 'NFC Tag Reading' for your App ID [here](https://developer.apple.com/account/ios/identifier/bundle).
 
-Note that to be able to use NFC you'll need to build with Xcode 9 (beta), so open Xcode and run the app from there.
+Note that to be able to use NFC you'll need to have Xcode 9 installed, and (at least) NativeScript version 3.2.0 (so if `tns --version` is lower, do `npm i -g nativescript`).
 
-Also, add this to your `App_Resources/iOS/*.entitlements` file:
+Also, add this to your `App_Resources/iOS/app.entitlements` (mind the name!) file:
 
 ```xml
 	<key>com.apple.developer.nfc.readersession.formats</key>
@@ -121,13 +121,16 @@ nfc.enabled().then((on) => {
 ```
 
 ### `setOnNdefDiscoveredListener`
-You may want to get notified when an Ndef tag was discovered.
-You can pass in a callback function that gets invoked when that is the case.
+You may want to get notified when an Ndef tag was discovered. You can pass in a callback function that gets invoked when that is the case.
 
 Note that blank/erased NFC tags are not returned here, but through `setOnTagDiscoveredListener` instead.
 
 See the [definition of NfcNdefData](https://github.com/EddyVerbruggen/nativescript-nfc/blob/master/nfc.common.d.ts#L27-L33) to learn what is returned to the callback function.
 
+For iOS you can pass in these options (see the TypeScript example below):
+* `stopAfterFirstRead: boolean` (default `false`): don't continue scanning after a tag was read. 
+* `scanHint: string` (default `undefined`): Show a little hint in the scan UI.
+
 ##### JavaScript
 ```js
 nfc.setOnNdefDiscoveredListener(function(data) {
@@ -151,6 +154,10 @@ nfc.setOnNdefDiscoveredListener((data: NfcNdefData) => {
       console.log("Ndef discovered! Message record: " + record.payloadAsString);
     }
   }
+}, {
+  // iOS-specific options
+  stopAfterFirstRead: true,
+  scanHint: "Scan a tag, baby!"
 }).then(() => {
     console.log("OnNdefDiscovered listener added");
 });

demo/app/App_Resources/iOS/build.xcconfig

@@ -4,6 +4,4 @@
 ASSETCATALOG_COMPILER_APPICON_NAME = AppIcon;
 ASSETCATALOG_COMPILER_LAUNCHIMAGE_NAME = LaunchImage;
 
-DEVELOPMENT_TEAM = 8Q5F6M3TNS
-
-CODE_SIGN_ENTITLEMENTS = demo.entitlements
+DEVELOPMENT_TEAM = 8Q5F6M3TNS

demo/app/main-view-model.ts

@@ -3,7 +3,7 @@ import { alert } from "tns-core-modules/ui/dialogs";
 import { Nfc, NfcTagData, NfcNdefData } from "nativescript-nfc";
 
 export class HelloWorldModel extends observable.Observable {
-  public lastNdefDiscovered: string = "";
+  public lastNdefDiscovered: string = "Press a button...";
   private nfc: Nfc;
 
   constructor() {
@@ -37,50 +37,40 @@ export class HelloWorldModel extends observable.Observable {
     }).then(() => {
       console.log("OnTagDiscovered Listener set");
     }, (err) => {
-      alert(err);
+      console.log(err);
     });
   }
 
   public doStopTagListener() {
     this.nfc.setOnTagDiscoveredListener(null).then(() => {
       console.log("OnTagDiscovered nulled");
     }, (err) => {
-      alert(err);
+      console.log(err);
     });
   }
 
   public doStartNdefListener() {
-    const that = this;
     this.nfc.setOnNdefDiscoveredListener((data: NfcNdefData) => {
       if (data.message) {
         let tagMessages = [];
         // data.message is an array of records, so:
         data.message.forEach(record => {
-          console.log(">>> record.tnf: " + record.tnf);
-          console.log(">>> record.type: " + record.type);
-          console.log(">>> record.payload: " + record.payload);
-          console.log(">>> record.payloadAsString: " + record.payloadAsString);
-          console.log(">>> record.payloadAsHexString: " + record.payloadAsHexString);
+          console.log("Read record: " + JSON.stringify(record));
           tagMessages.push(record.payloadAsString);
         });
-        that.set("lastNdefDiscovered", "Read: " + tagMessages.join(", "));
-        console.log("Read: " + tagMessages.join(", "));
-        alert({
-          title: "Ndef tag contents read:",
-          message: " - " + tagMessages.join("\n - "),
-          okButtonText: "OK :)"
-        });
+        this.set("lastNdefDiscovered", "Read: " + tagMessages.join(", "));
       }
-    }, {stopAfterFirstRead: true}).then(() => {
-      console.log("OnNdefDiscoveredListener set");
-    }, (err) => {
-      alert(err);
-    });
+    }, {
+      stopAfterFirstRead: true,
+      scanHint: "Scan a tag, baby!"
+    })
+        .then(() => this.set("lastNdefDiscovered", "Listening..."))
+        .catch(err => alert(err));
   }
 
   public doStopNdefListener() {
     this.nfc.setOnNdefDiscoveredListener(null).then(() => {
-      console.log("OnNdefDiscoveredListener nulled");
+      this.set("lastNdefDiscovered", "Stopped listening.");
     }, (err) => {
       alert(err);
     });
@@ -95,9 +85,9 @@ export class HelloWorldModel extends observable.Observable {
         }
       ]
     }).then(() => {
-      console.log("Wrote text 'Hello!'");
+      this.set("lastNdefDiscovered", "Wrote text 'Hello!'");
     }, (err) => {
-      alert(err);
+      console.log(err);
     });
   }
 
@@ -110,17 +100,17 @@ export class HelloWorldModel extends observable.Observable {
         }
       ]
     }).then(() => {
-      console.log("Wrote uri 'https://www.telerik.com");
+      this.set("lastNdefDiscovered", "Wrote uri 'https://www.telerik.com");
     }, (err) => {
-      alert(err);
+      console.log(err);
     });
   }
 
   public doEraseTag() {
     this.nfc.eraseTag().then(() => {
-      console.log("Tag erased");
+      this.set("lastNdefDiscovered", "Tag erased");
     }, (err) => {
-      alert(err);
+      console.log(err);
     });
   }
 }