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

Only Android supports nfc tag writing

Installation

Add to pubspec.yaml:

dependencies:
  flutter_nfc_reader: ^0.1.0

or to get the experimental one:

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

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 19 in minSdkVersion in the build.gradle (Module: app)

defaultConfig {
...
minSdkVersion 19
...
}

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:

FlutterNfcReader.read() and FlutterNfcReader.onTagDiscovered() have an optional parameter, only for iOS, called instruction. You can pass a String that contains information to be shown in the modal screen.

• 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.

Check NFC Availability

In order to check whether the Device supports NFC or not you can call FlutterNfcReader.checkNFCAvailability(). The method returns NFCAvailability.available when NFC is supported and enabled, NFCAvailability.disabled when NFC is disabled (Android only) and NFCAvailability.not_supported when the user's hardware does not support NFC.

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:

https://github.com/flutter/flutter/issues/20685