Flutter NFC Reader & Writer

A new flutter plugin to help developers looking to use internal hardware inside iOS or Android devices for reading and writing NFC tags.

The system activate a pooling reading session that stops automatically once a tag has been recognised. You can also trigger the stop event manually using a dedicated function.

Supported NFC Format

PlatformSupported NFC Tags
AndroidNDEF: A, B, F, V, BARCODE
iOSNDEF: NFC TYPE 1, 2, 3, 4, 5

Only Android supports nfc tag writing

Installation

Add to pubspec.yaml:

dependencies:
  flutter_nfc_reader:
    git:
      url: git://github.com/matteocrippa/flutter-nfc-reader.git
      ref: master

and then run the shell

flutter packages get

last step import to the project:

import 'package:flutter_nfc_reader/flutter_nfc_reader.dart';

How to use

Android setup

Add those two lines to your AndroidManifest.xml on the top

<uses-permission android:name="android.permission.NFC" />
<uses-feature
        android:name="android.hardware.nfc"
        android:required="true" />

Assign 18 in minSdkVersion in the build.gradle (Module: app)

defaultConfig {
...
minSdkVersion 18
...
}

iOS Setup

Atm only Swift based Flutter project are supported.

  • Enable Capabilities / Near Field Communication Tag Reading.
  • Info.plist file, add Privacy - NFC Scan Usage Description with string value NFC Tag.

In your Podfile add this code in the top

platform :ios, '8.0'
use_frameworks!

Read NFC

This function will return a promise when a read occurs, till that very moment the reading session is open. The promise will return a NfcData model, this model contains:

  • id > id of the tag
  • content > content of the tag
  • error > if any error occurs
FlutterNfcReader.read().then((response) {
    print(response.content);
});

Stream NFC

this function will return a Stream that emits NfcData everytime a tag is recognized. On Ios you can use this too but IOS will always show a bottom sheet when it wants to scan a NFC Tag. Therefore you need to explicitly cast FlutterNfcReader.read() when you expect a second value. When subscribing to the stream the read function is called a first time for you. View the Example for a sample implementation.

FlutterNfcReader.onTagDiscovered().listen((onData) {
  print(onData.id);
  print(onData.content);
});

Write NFC (Only Android)

This function will return a promise when a write occurs, till that very moment the reading session is open. The promise will return a NfcData model, this model contains:

  • content > writed in the tag
FlutterNfcReader.write("path_prefix","tag content").then((response) {
print(response.content);
});

Read & Write NFC (Only Android)

You can read and then write in an nfc tag using the above functions as follows

FlutterNfcReader.read().then((readResponse) {
    FlutterNfcReader.write(" ",readResponse.content).then((writeResponse) {
        print('writed: ${writeResponse.content}');
    });
});

Stop NFC

  • status > status of ncf reading or writing stoped
FlutterNfcReader.stop().then((response) {
    print(response.status.toString());
});

For better details look at the demo app.

IOS Specifics

IOS behaves a bit different in terms of NFC Scanning and writing.

  • Ids of the tags aren't possible in the current implementation
  • each scan is visible for the user with a bottom sheet

Getting Started

For help getting started with Flutter, view our online documentation.

For help on editing plugin code, view the documentation.

Contributing

Please take a quick look at the contribution guidelines first. If you see a package or project here that is no longer maintained or is not a good fit, please submit a pull request to improve this file. Thank you to all contributors!!

to develop on ios you need to activate the "legacy" build system because of this issue in flutter:

github.com/flutter/flutter/issues/20685

Libraries

flutter_nfc_reader