npm package: @red-mobile/cordova-plugin-nfc
Description: Near Field Communication (NFC) Plugin. Read and write NDEF messages to NFC tags and share NDEF messages with peers.
Author: Hiroyuki Okada
Latest version: 1.3.0

Cordova NFC Plugin
==========================

The NFC plugin allows you to read and write  NFC tags. You can also beam to, and receive from, other NFC enabled devices.

Use to
* read data from NFC tags
* write data to NFC tags
* send data to other NFC enabled devices
* receive data from NFC devices
* send raw commands (ISO 14443-3A, ISO 14443-3A, ISO 14443-4, JIS 6319-4, ISO 15693) to NFC tags

This plugin uses NDEF (NFC Data Exchange Format) for maximum compatibilty between NFC devices, tag types, and operating systems.

Supported Platforms
-------------------
* Android
* [iOS 11](#ios-notes)

## Contents

* [Installing](#installing)
* [NFC](#nfc)
* [NDEF](#ndef)
  - [NdefMessage](#ndefmessage)
  - [NdefRecord](#ndefrecord)
* [Events](#events)
* [Platform Differences](#platform-differences)
* [Launching Application when Scanning a Tag](#launching-your-android-application-when-scanning-a-tag)
* [Testing](#testing)
* [Sample Projects](#sample-projects)
* [Host Card Emulation (HCE)](#hce)
* [Book](#book)
* [License](#license)

# Installing

### Cordova

    $ cordova plugin add @red-mobile/cordova-plugin-nfc

### PhoneGap

    $ phonegap plugin add @red-mobile/cordova-plugin-nfc

### PhoneGap Build

Edit config.xml to install the plugin for [PhoneGap Build](http://build.phonegap.com).

    <preference name="phonegap-version" value="cli-9.0.0" />
    <plugin name="phonegap-nfc" source="npm" />

## iOS Notes

Reading NFC NDEF tags is supported on iPhone 7 (and newer) since iOS 11. iOS 13 added support for writing NDEF messages to NFC tags. iOS 13 also adds the ability to get the UID from some NFC tags. On iOS, the user must start a NFC session to scan for a tag. This is different from Android which can constantly scan for NFC tags. The [nfc.scanNdef](#nfcscanndef) and [nfc.scanTag](#nfcscantag) functions start a NFC scanning session. The NFC tag is returned to the caller via a Promise. If your existing code uses the deprecated [nfc.beginSession](#nfcbeginsession), update it to use `nfc.scanNdef`.

The `scanNdef` function uses [NFCNDEFReaderSession](https://developer.apple.com/documentation/corenfc/nfcndefreadersession) to detect NFC Data Exchange Format (NDEF) tags. `scanTag` uses the newer [NFCTagReaderSession](https://developer.apple.com/documentation/corenfc/nfctagreadersession) available in iOS 13 to detect ISO15693, FeliCa, and MIFARE tags. The `scanTag` function will include the tag UID and tag type for *some* NFC tags along with the NDEF messages. `scanTag` can also read some RFID tags without NDEF messsages. `scanTag` will not scan some NDEF tags including Topaz and Mifare Classic.

You must call [nfc.scanNdef](#nfcscanndef) and [nfc.scanTag](#nfcscantag) before every scan.

Writing NFC tags on iOS uses the same [nfc.write](#nfcwrite) function as other platforms. Although it's the same function, the behavior is different on iOS. Calling `nfc.write` on an iOS device will start a new scanning session and write data to the scanned tag.

# NFC

> The nfc object provides access to the device's NFC sensor.

## Methods

- [nfc.addNdefListener](#nfcaddndeflistener)
- [nfc.addTagDiscoveredListener](#nfcaddtagdiscoveredlistener)
- [nfc.addMimeTypeListener](#nfcaddmimetypelistener)
- [nfc.addNdefFormatableListener](#nfcaddndefformatablelistener)
- [nfc.write](#nfcwrite)
- [nfc.makeReadOnly](#nfcmakereadonly)
- [nfc.erase](#nfcerase)
- [nfc.enabled](#nfcenabled)
- [nfc.showSettings](#nfcshowsettings)
- [~~nfc.beginSession~~](#nfcbeginsession)
- [~~nfc.invalidateSession~~](#nfcinvalidatesession)
- [nfc.scanNdef](#nfcscanndef)
- [nfc.scanTag](#nfcscanTag)
- [nfc.cancelScan](#nfccancelscan)

## ReaderMode

- [nfc.readerMode](#nfcreadermode)
- [nfc.disableReaderMode](#nfcdisablereadermode)

## Tag Technology Functions

- [nfc.connect](#nfcconnect)
- [nfc.transceive](#nfctransceive)
- [nfc.close](#nfcclose)
- [ISO-DEP example](#tag-technology-functions-1)

## nfc.addNdefListener

Registers an event listener for any NDEF tag.

    nfc.addNdefListener(callback, [onSuccess], [onFailure]);

### Parameters

- __callback__: The callback that is called when an NDEF tag is read.
- __onSuccess__: (Optional) The callback that is called when the listener is added.
- __onFailure__: (Optional) The callback that is called if there was an error.

### Description

Function `nfc.addNdefListener` registers the callback for ndef events.

A ndef event is fired when a NDEF tag is read.

On Android registered [mimeTypeListeners](#nfcaddmimetypelistener) takes precedence over this more generic NDEF listener.

On iOS you must call [beingSession](#nfcbeginsession) before scanning a tag.

### Supported Platforms

- Android
- iOS

## nfc.removeNdefListener

Removes the previously registered event listener for NDEF tags added via `nfc.addNdefListener`.

    nfc.removeNdefListener(callback, [onSuccess], [onFailure]);

Removing listeners is not recommended. Instead, consider that your callback can ignore messages you no longer need.

### Parameters

- __callback__: The previously registered callback.
- __onSuccess__: (Optional) The callback that is called when the listener is successfully removed.
- __onFailure__: (Optional) The callback that is called if there was an error during removal.

### Supported Platforms

- Android
- iOS
- Windows

## nfc.addTagDiscoveredListener

Registers an event listener for tags matching any tag type.

    nfc.addTagDiscoveredListener(callback, [onSuccess], [onFailure]);

### Parameters

- __callback__: The callback that is called when a tag is detected.
- __onSuccess__: (Optional) The callback that is called when the listener is added.
- __onFailure__: (Optional) The callback that is called if there was an error.

### Description

Function `nfc.addTagDiscoveredListener` registers the callback for tag events.

This event occurs when any tag is detected by the phone.

### Supported Platforms

- Android

Note that Windows Phones need the newere NXP PN427 chipset to read non-NDEF tags. That tag will be read, but no tag meta-data is available.

## nfc.removeTagDiscoveredListener

Removes the previously registered event listener added via `nfc.addTagDiscoveredListener`.

    nfc.removeTagDiscoveredListener(callback, [onSuccess], [onFailure]);

Removing listeners is not recommended. Instead, consider that your callback can ignore messages you no longer need.

### Parameters

- __callback__: The previously registered callback.
- __onSuccess__: (Optional) The callback that is called when the listener is successfully removed.
- __onFailure__: (Optional) The callback that is called if there was an error during removal.

### Supported Platforms

- Android

## nfc.addMimeTypeListener

Registers an event listener for NDEF tags matching a specified MIME type.

    nfc.addMimeTypeListener(mimeType, callback, [onSuccess], [onFailure]);

### Parameters

- __mimeType__: The MIME type to filter for messages.
- __callback__: The callback that is called when an NDEF tag matching the MIME type is read.
- __onSuccess__: (Optional) The callback that is called when the listener is added.
- __onFailure__: (Optional) The callback that is called if there was an error.

### Description

Function `nfc.addMimeTypeListener` registers the callback for ndef-mime events.

A ndef-mime event occurs when a `Ndef.TNF_MIME_MEDIA` tag is read and matches the specified MIME type.

This function can be called multiple times to register different MIME types. You should use the *same* handler for all MIME messages.

    nfc.addMimeTypeListener("text/json", *onNfc*, success, failure);
    nfc.addMimeTypeListener("text/demo", *onNfc*, success, failure);

On Android, MIME types for filtering should always be lower case. (See [IntentFilter.addDataType()](http://developer.android.com/reference/android/content/IntentFilter.html#addDataType\(java.lang.String\)))

### Supported Platforms

- Android

## nfc.removeMimeTypeListener

Removes the previously registered event listener added via `nfc.addMimeTypeListener`.

    nfc.removeMimeTypeListener(mimeType, callback, [onSuccess], [onFailure]);

Removing listeners is not recommended. Instead, consider that your callback can ignore messages you no longer need.

### Parameters

- __mimeType__: The MIME type to filter for messages.
- __callback__: The previously registered callback.
- __onSuccess__: (Optional) The callback that is called when the listener is successfully removed.
- __onFailure__: (Optional) The callback that is called if there was an error during removal.

### Supported Platforms

- Android

## nfc.addNdefFormatableListener

Registers an event listener for formatable NDEF tags.

    nfc.addNdefFormatableListener(callback, [onSuccess], [onFailure]);

### Parameters

- __callback__: The callback that is called when NDEF formatable tag is read.
- __onSuccess__: (Optional) The callback that is called when the listener is added.
- __onFailure__: (Optional) The callback that is called if there was an error.

### Description

Function `nfc.addNdefFormatableListener` registers the callback for ndef-formatable events.

A ndef-formatable event occurs when a tag is read that can be NDEF formatted.  This is not fired for tags that are already formatted as NDEF.  The ndef-formatable event will not contain an NdefMessage.

### Supported Platforms

- Android

## nfc.write

Writes an NDEF Message to a NFC tag.

A NDEF Message is an array of one or more NDEF Records

    var message = [
        ndef.textRecord("hello, world"),
        ndef.uriRecord("http://github.com/chariotsolutions/phonegap-nfc")
    ];

    nfc.write(message, [onSuccess], [onFailure]);

### Parameters

- __ndefMessage__: An array of NDEF Records.
- __onSuccess__: (Optional) The callback that is called when the tag is written.
- __onFailure__: (Optional) The callback that is called if there was an error.

### Description

Function `nfc.write` writes an NdefMessage to a NFC tag.

On **Android** this method *must* be called from within an NDEF Event Handler.

On **iOS** this method can be called outside the NDEF Event Handler, it will start a new scanning session. Optionally you can reuse the read session to write data. See example below.

On **Windows** this method *may* be called from within the NDEF Event Handler.

On **Windows Phone 8.1** this method should be called outside the NDEF Event Handler, otherwise Windows tries to read the tag contents as you are writing to the tag.

### Examples

#### Android

On Android, write must be called inside an event handler

    function onNfc(nfcEvent) {

        console.log(nfcEvent.tag);

        var message = [
            ndef.textRecord(new String(new Date()))
        ];

        nfc.write(
            message,
            success => console.log('wrote data to tag'),
            error => console.log(error)
        );

    nfc.addNdefListener(onNfc);


#### iOS - Simple

Calling `nfc.write` on iOS will create a new session and write data when the user taps a NFC tag

        var message = [
            ndef.textRecord("Hello, world")
        ];

        nfc.write(
            message,
            success => console.log('wrote data to tag'),
            error => console.log(error)
        );

#### iOS - Read and Write

On iOS you can optionally write to NFC tag using the read session

        try {
            let tag = await nfc.scanNdef({ keepSessionOpen: true});

            // you can read tag data here
            console.log(tag);

            // this example writes a new message with a timestamp
            var message = [
                ndef.textRecord(new String(new Date()))
            ];

            nfc.write(
                message,
                success => console.log('wrote data to tag'),
                error => console.log(error)
            );

        } catch (err) {
            console.log(err);
        }

### Supported Platforms

- Android
- iOS

## nfc.makeReadOnly

Makes a NFC tag read only.  **Warning this is permanent.**

    nfc.makeReadOnly([onSuccess], [onFailure]);

### Parameters

- __onSuccess__: (Optional) The callback that is called when the tag is locked.
- __onFailure__: (Optional) The callback that is called if there was an error.

### Description

Function `nfc.makeReadOnly` make a NFC tag read only. **Warning this is permanent** and can not be undone.

On **Android** this method *must* be called from within an NDEF Event Handler.

Example usage

    onNfc: function(nfcEvent) {

        var record = [
            ndef.textRecord("hello, world")
        ];

        var failure = function(reason) {
            alert("ERROR: " + reason);
        };

        var lockSuccess = function() {
            alert("Tag is now read only.");
        };

        var lock = function() {
            nfc.makeReadOnly(lockSuccess, failure);
        };

        nfc.write(record, lock, failure);

    },

### Supported Platforms

- Android

## nfc.erase

Erase a NDEF tag

    nfc.erase([onSuccess], [onFailure]);

### Parameters

- __onSuccess__: (Optional) The callback that is called when sharing stops.
- __onFailure__: (Optional) The callback that is called if there was an error.

### Description

Function `nfc.erase` erases a tag by writing an empty message.  Will format unformatted tags before writing.

This method *must* be called from within an NDEF Event Handler.

### Supported Platforms

- Android

## nfc.showSettings

Show the NFC settings on the device.

    nfc.showSettings(success, failure);

### Description

Function `showSettings` opens the NFC settings for the operating system.

### Parameters

- __success__: Success callback function [optional]
- __failure__: Error callback function, invoked when error occurs. [optional]

### Quick Example

    nfc.showSettings();

### Supported Platforms

- Android

## nfc.enabled

Check if NFC is available and enabled on this device.

nfc.enabled(onSuccess, onFailure);

### Parameters

- __onSuccess__: The callback that is called when NFC is enabled.
- __onFailure__: The callback that is called when NFC is disabled or missing.

### Description

Function `nfc.enabled` explicitly checks to see if the phone has NFC and if NFC is enabled. If
everything is OK, the success callback is called. If there is a problem, the failure callback
will be called with a reason code.

The reason will be **NO_NFC** if the device doesn't support NFC and **NFC_DISABLED** if the user has disabled NFC.

Note: that on Android the NFC status is checked before every API call **NO_NFC** or **NFC_DISABLED** can be returned in **any** failure function.

Windows will return **NO_NFC_OR_NFC_DISABLED** when NFC is not present or disabled. If the user disabled NFC after the application started, Windows may return **NFC_DISABLED**. Windows checks the NFC status before most API calls, but there are some cases when the NFC state can not be determined.

### Supported Platforms

- Android
- iOS
- Windows

## nfc.beginSession

**`beginSession` is deprecated. Use `scanNdef` or `scanTag`**

iOS requires you to begin a session before scanning a NFC tag.

    nfc.beginSession(success, failure);

### Description

**`beginSession` is deprecated. Use `scanNdef` or `scanTag`**

Function `beginSession` starts the [NFCNDEFReaderSession](https://developer.apple.com/documentation/corenfc/nfcndefreadersession) allowing iOS to scan NFC tags. Use [nfc.addNdefListener](#nfcaddndeflistener) to receive the results of the scan.

### Parameters

- __success__: Success callback function called when the session begins [optional]
- __failure__: Error callback function, invoked when error occurs. [optional]

### Quick Example

    nfc.beginSession();

### Supported Platforms

- iOS

## nfc.invalidateSession

**`invalidateSession` is deprecated. Use `cancelScan``.**

Invalidate the NFC session.

    nfc.invalidateSession(success, failure);

### Description

Function `invalidateSession` stops the [NFCNDEFReaderSession](https://developer.apple.com/documentation/corenfc/nfcndefreadersession) returning control to your app.

### Parameters

- __success__: Success callback function called when the session in invalidated [optional]
- __failure__: Error callback function, invoked when error occurs. [optional]

### Quick Example

    nfc.invalidateSession();

### Supported Platforms

- iOS

## nfc.scanNdef

Calling `scanNdef` will being an iOS NFC scanning session. The NFC tag will be returned in a Promise.

    nfc.scanNdef();

### Description

Function `scanNdef` starts the [NFCNDEFReaderSession](https://developer.apple.com/documentation/corenfc/nfcndefreadersession)  allowing iOS to scan NFC tags.

### Returns

 - Promise

### Quick Example

    // Promise
    nfc.scanNdef().then(
        tag => console.log(JSON.stringify(tag)),
        err => console.log(err)
    );

    // Async Await
    try {
        let tag = await nfc.scanNdef();
        console.log(JSON.stringify(tag));
    } catch (err) {
        console.log(err);
    }


### Supported Platforms

- iOS

## nfc.scanTag

Calling `scanTag` will being an iOS NFC scanning session. The NFC tag will be returned in a Promise.

    nfc.scanTag();

### Description

Function `scanTag` starts the [NFCTagReaderSession](https://developer.apple.com/documentation/corenfc/nfctagreadersession) allowing iOS to scan NFC tags.

The Tag reader will attempt to get the UID from the NFC Tag. If can also read the UID from some non-NDEF tags.

Use [scanNdef](#nfcscanndef) for reading NFC tags on iOS unless you need to get the tag UID.

### Returns

 - Promise

### Quick Example

    // Promise
    nfc.scanTag().then(
        tag => {
            console.log(JSON.stringify(tag))
            if (tag.id) {
                console.log(nfc.bytesToHexString(tag.id));
            }
        },
        err => console.log(err)
    );

    // Async Await
    try {
        let tag = await nfc.scanTag();
        console.log(JSON.stringify(tag));
        if (tag.id) {
            console.log(nfc.bytesToHexString(tag.id));
        }
    } catch (err) {
        console.log(err);
    }


### Supported Platforms

- iOS


## nfc.cancelScan

Invalidate the NFC session started by `scanNdef` or `scanTag`.

    nfc.cancelScan();

### Description

Function `cancelScan` stops the [NFCReaderSession](https://developer.apple.com/documentation/corenfc/nfcreadersession) returning control to your app.

### Returns

 - Promise

### Quick Example

    nfc.cancelScan().then(
        success => { console.log('Cancelled NFC session')},
        err => { console.log(`Error cancelling session ${err}`)}
    );

### Supported Platforms

- iOS


# Reader Mode Functions

## nfc.readerMode

Read NFC tags sending the tag data to the success callback.

    nfc.readerMode(flags, readCallback, errorCallback);

### Description

In reader mode, when a NFC tags is read, the results are returned to read callback as a tag object. Note that the normal event listeners are *not* used in reader mode. The callback receives the tag object *without* the event wrapper.

    {
        "isWritable": true,
        "id": [4, 96, 117, 74, -17, 34, -128],
        "techTypes": ["android.nfc.tech.IsoDep", "android.nfc.tech.NfcA", "android.nfc.tech.Ndef"],
        "type": "NFC Forum Type 4",
        "canMakeReadOnly": false,
        "maxSize": 2046,
        "ndefMessage": [{
            "id": [],
            "type": [116, 101, 120, 116, 47, 112, 103],
            "payload": [72, 101, 108, 108, 111, 32, 80, 104, 111, 110, 101, 71, 97, 112],
            "tnf": 2
        }]
    }

Foreground dispatching and peer-to-peer functions are disabled when reader mode is enabled.

The flags control which tags are scanned. One benefit to reader mode, is the system sounds can be disabled when a NFC tag is scanned by adding the nfc.FLAG_READER_NO_PLATFORM_SOUNDS flag. See Android's [NfcAdapter.enableReaderMode()](https://developer.android.com/reference/android/nfc/NfcAdapter#enableReaderMode(android.app.Activity,%20android.nfc.NfcAdapter.ReaderCallback,%20int,%20android.os.Bundle)) documentation for more info on the flags.


### Parameters

- __flags__:  Flags indicating poll technologies and other optional parameters
- __readCallback__: The callback that is called when a NFC tag is scanned.
- __errorCallback__: The callback that is called when NFC is disabled or missing.

### Quick Example

    nfc.readerMode(
        nfc.FLAG_READER_NFC_A | nfc.FLAG_READER_NO_PLATFORM_SOUNDS,
        nfcTag => console.log(JSON.stringify(nfcTag)),
        error => console.log('NFC reader mode failed', error)
    );

### Supported Platforms

- Android

## nfc.disableReaderMode

Disable NFC reader mode.

    nfc.disableNfcReaderMode(successCallback, errorCallback);

### Description

Disable NFC reader mode.

### Parameters

- __successCallback__: The callback that is called when a NFC reader mode is disabled.
- __errorCallback__: The callback that is called when NFC reader mode can not be disabled.

### Quick Example

    nfc.disableReaderMode(
        () => console.log('NFC reader mode disabled'),
        error => console.log('Error disabling NFC reader mode', error)
    )

### Supported Platforms

- Android


# Tag Technology Functions

The tag technology functions provide access to I/O operations on a tag. Connect to a tag, send commands with transceive, close the tag. See the [Android TagTechnology](https://developer.android.com/reference/android/nfc/tech/TagTechnology) and implementations like [IsoDep](https://developer.android.com/reference/android/nfc/tech/IsoDep) and [NfcV](https://developer.android.com/reference/android/nfc/tech/NfcV) for more details. These new APIs are promise based rather than using callbacks.

#### ISO-DEP (ISO 14443-4) Example

    const DESFIRE_SELECT_PICC = '00 A4 04 00 07 D2 76 00 00 85 01 00';
    const DESFIRE_SELECT_AID = '90 5A 00 00 03 AA AA AA 00'

    async function handleDesfire(nfcEvent) {

        const tagId = nfc.bytesToHexString(nfcEvent.tag.id);
        console.log('Processing', tagId);

        try {
            await nfc.connect('android.nfc.tech.IsoDep', 500);
            console.log('connected to', tagId);

            let response = await nfc.transceive(DESFIRE_SELECT_PICC);
            ensureResponseIs('9000', response);

            response = await nfc.transceive(DESFIRE_SELECT_AID);
            ensureResponseIs('9100', response);
            // 91a0 means the requested application not found

            alert('Selected application AA AA AA');

            // more transcieve commands go here

        } catch (error) {
            alert(error);
        } finally {
            await nfc.close();
            console.log('closed');
        }

    }

    function ensureResponseIs(expectedResponse, buffer) {
        const responseString = util.arrayBufferToHexString(buffer);
        if (expectedResponse !== responseString) {
            const error = 'Expecting ' + expectedResponse + ' but received ' + responseString;
            throw error;
        }
    }

    function onDeviceReady() {
        nfc.addTagDiscoveredListener(handleDesfire);
    }

    document.addEventListener('deviceready', onDeviceReady, false);

## nfc.connect

Connect to the tag and enable I/O operations to the tag from this TagTechnology object.

    nfc.connect(tech);

    nfc.connect(tech, timeout);

### Description

Function `connect` enables I/O operations to the tag from this TagTechnology object. `nfc.connect` should be called after receiving a nfcEvent from the `addTagDiscoveredListener` or the `readerMode` callback. Only one TagTechnology object can be connected to a Tag at a time.

See Android's [TagTechnology.connect()](https://developer.android.com/reference/android/nfc/tech/TagTechnology.html#connect()) for more info.

### Parameters

- __tech__: The tag technology e.g. android.nfc.tech.IsoDep
- __timeout__: The transceive(byte[]) timeout in milliseconds [optional]

### Returns

 - Promise when the connection is successful, optionally with a maxTransceiveLength attribute in case the tag technology supports it

### Quick Example

    nfc.addTagDiscoveredListener(function(nfcEvent) {
        nfc.connect('android.nfc.tech.IsoDep', 500).then(
            () => console.log('connected to', nfc.bytesToHexString(nfcEvent.tag.id)),
            (error) => console.log('connection failed', error)
        );
    })

### Supported Platforms

- Android

## nfc.transceive

Send raw command to the tag and receive the response.

    nfc.transceive(data);

### Description

Function `transceive` sends raw commands to the tag and receives the response. `nfc.connect` must be called before calling `transceive`. Data passed to transceive can be a hex string representation of bytes or an ArrayBuffer. The response is returned as an ArrayBuffer in the promise.

See Android's documentation [IsoDep.transceive()](https://developer.android.com/reference/android/nfc/tech/IsoDep.html#transceive(byte[])), [NfcV.transceive()](https://developer.android.com/reference/android/nfc/tech/NfcV.html#transceive(byte[])), [MifareUltralight.transceive()](https://developer.android.com/reference/android/nfc/tech/MifareUltralight.html#transceive(byte[])) for more info.

### Parameters

- __data__: a string of hex data or an ArrayBuffer

### Returns

 - Promise with the response data as an ArrayBuffer

### Quick Example

    // Promise style
    nfc.transceive('90 5A 00 00 03 AA AA AA 00').then(
        response => console.log(util.arrayBufferToHexString(response)),
        error => console.log('Error selecting DESFire application')
    )

    // async await
    const response = await nfc.transceive('90 5A 00 00 03 AA AA AA 00');
    console.log('response =',util.arrayBufferToHexString(response));

### Supported Platforms

- Android

## nfc.close

Close TagTechnology connection.

    nfc.close();

### Description

Function `close` disabled I/O operations to the tag from this TagTechnology object, and releases resources.

See Android's [TagTechnology.close()](https://developer.android.com/reference/android/nfc/tech/TagTechnology.html#close()) for more info.

### Parameters

 - none

### Returns

 - Promise when the connection is successfully closed

### Quick Example

    nfc.transceive().then(
        () => console.log('connection closed'),
        (error) => console.log('error closing connection', error);
    )

### Supported Platforms

- Android

# NDEF

> The `ndef` object provides NDEF constants, functions for creating NdefRecords, and functions for converting data.
> See [android.nfc.NdefRecord](http://developer.android.com/reference/android/nfc/NdefRecord.html) for documentation about constants

## NdefMessage

Represents an NDEF (NFC Data Exchange Format) data message that contains one or more NdefRecords.
This plugin uses an array of NdefRecords to represent an NdefMessage.

## NdefRecord

Represents a logical (unchunked) NDEF (NFC Data Exchange Format) record.

### Properties

- __tnf__: 3-bit TNF (Type Name Format) - use one of the TNF_* constants
- __type__: byte array, containing zero to 255 bytes, must not be null
- __id__: byte array, containing zero to 255 bytes, must not be null
- __payload__: byte array, containing zero to (2 ** 32 - 1) bytes, must not be null

The `ndef` object has a function for creating NdefRecords

    var type = "text/pg",
        id = [],
        payload = nfc.stringToBytes("Hello World"),
        record = ndef.record(ndef.TNF_MIME_MEDIA, type, id, payload);

There are also helper functions for some types of records

Create a URI record

    var record = ndef.uriRecord("http://chariotsolutions.com");

Create a plain text record

    var record = ndef.textRecord("Plain text message");

Create a mime type record

    var mimeType = "text/pg",
        payload = "Hello Phongap",
        record = ndef.mimeMediaRecord(mimeType, nfc.stringToBytes(payload));

Create an Empty record

    var record = ndef.emptyRecord();

Create an Android Application Record (AAR)

    var record = ndef.androidApplicationRecord('com.example');

See `ndef.record`, `ndef.textRecord`, `ndef.mimeMediaRecord`, and `ndef.uriRecord`.

The Ndef object has functions to convert some data types to and from byte arrays.

See the [phonegap-nfc.js](https://github.com/chariotsolutions/phonegap-nfc/blob/master/www/phonegap-nfc.js) source for more documentation.

# Events

Events are fired when NFC tags are read.  Listeners are added by registering callback functions with the `nfc` object.  For example ` nfc.addNdefListener(myNfcListener, win, fail);`

## NfcEvent

### Properties

- __type__: event type
- __tag__: Ndef tag

### Types

- tag
- ndef-mime
- ndef
- ndef-formatable

The tag contents are platform dependent.

`id` and `serialNumber` are different names for the same value.  `id` is typically displayed as a hex string `nfc.bytesToHexString(tag.id)`.

Assuming the following NDEF message is written to a tag, it will produce the following events when read.

    var ndefMessage = [
        ndef.createMimeRecord('text/pg', 'Hello PhoneGap')
    ];

#### Sample Event on Android

    {
        type: 'ndef',
        tag: {
            "isWritable": true,
            "id": [4, 96, 117, 74, -17, 34, -128],
            "techTypes": ["android.nfc.tech.IsoDep", "android.nfc.tech.NfcA", "android.nfc.tech.Ndef"],
            "type": "NFC Forum Type 4",
            "canMakeReadOnly": false,
            "maxSize": 2046,
            "ndefMessage": [{
                "id": [],
                "type": [116, 101, 120, 116, 47, 112, 103],
                "payload": [72, 101, 108, 108, 111, 32, 80, 104, 111, 110, 101, 71, 97, 112],
                "tnf": 2
            }]
        }
    }

# Platform Differences

## Multiple Listeners

Multiple listeners can be registered in JavaScript. e.g. addNdefListener, addTagDiscoveredListener, addMimeTypeListener.

On Android, only the most specific event will fire.  If a Mime Media Tag is scanned, only the addMimeTypeListener callback is called and not the callback defined in addNdefListener. You can use the same event handler for multiple listeners.

## addTagDiscoveredListener

On Android, addTagDiscoveredListener scans non-NDEF tags and NDEF tags. The tag event does NOT contain an ndefMessage even if there are NDEF messages on the tag.  Use addNdefListener or addMimeTypeListener to get the NDEF information.

### Non-NDEF tag scanned with addTagDiscoveredListener on *Android*

    {
        type: 'tag',
        tag: {
            "id": [-81, 105, -4, 64],
            "techTypes": ["android.nfc.tech.MifareClassic", "android.nfc.tech.NfcA", "android.nfc.tech.NdefFormatable"]
        }
    }


### NDEF tag scanned with addTagDiscoveredListener on *Android*

    {
        type: 'tag',
        tag: {
            "id": [4, 96, 117, 74, -17, 34, -128],
            "techTypes": ["android.nfc.tech.IsoDep", "android.nfc.tech.NfcA", "android.nfc.tech.Ndef"]
        }
    }

### Non-NDEF tag scanned with addTagDiscoveredListener on *Windows*

    {
        type: 'tag',
        tag: {
        }
    }

# Launching your Android Application when Scanning a Tag

On Android, intents can be used to launch your application when a NFC tag is read.  This is optional and configured in AndroidManifest.xml.

    <intent-filter>
      <action android:name="android.nfc.action.NDEF_DISCOVERED" />
      <data android:mimeType="text/pg" />
      <category android:name="android.intent.category.DEFAULT" />
    </intent-filter>

Note: `data android:mimeType="text/pg"` should match the data type you specified in JavaScript

We have found it necessary to add `android:noHistory="true"` to the activity element so that scanning a tag launches the application after the user has pressed the home button.

See the Android documentation for more information about [filtering for NFC intents](http://developer.android.com/guide/topics/connectivity/nfc/nfc.html#ndef-disc).

Testing
=======

Tests require the [Cordova Plugin Test Framework](https://github.com/apache/cordova-plugin-test-framework)

Create a new project

    git clone https://github.com/chariotsolutions/phonegap-nfc
    cordova create nfc-test com.example.nfc.test NfcTest
    cd nfc-test
    cordova platform add android
    cordova plugin add ../phonegap-nfc
    cordova plugin add ../phonegap-nfc/tests
    cordova plugin add https://github.com/apache/cordova-plugin-test-framework.git

Change the start page in `config.xml`

    <content src="cdvtests/index.html" />

Run the app on your phone

    cordova run


Sample Projects
================

- [Ionic NFC Reader](https://github.com/don/ionic-nfc-reader)
- [NFC Reader](https://github.com/don/phonegap-nfc-reader)
- [NFC Writer](https://github.com/don/phonegap-nfc-writer)
- [NFC Peer to Peer](https://github.com/don/phonegap-p2p)
- [ApacheCon 2014 Demos](https://github.com/don/apachecon-nfc-demos)
- [Rock Paper Scissors](https://github.com/don/rockpaperscissors) *Android 2.x only*

HCE
=======

For Host Card Emulation (HCE), try the [Cordova HCE Plugin](https://github.com/don/cordova-plugin-hce).

Book
=======
Need more info? Check out my book <a href="http://www.tkqlhce.com/click-7835726-11260198-1430755877000?url=http%3A%2F%2Fshop.oreilly.com%2Fproduct%2F0636920021193.do%3Fcmp%3Daf-prog-books-videos-product_cj_9781449372064_%2525zp&cjsku=0636920021193" target="_top">
Beginning NFC: Near Field Communication with Arduino, Android, and PhoneGap</a><img src="http://www.lduhtrp.net/image-7835726-11260198-1430755877000" width="1" height="1" border="0"/>

<a href="http://www.kqzyfj.com/click-7835726-11260198-1430755877000?url=http%3A%2F%2Fshop.oreilly.com%2Fproduct%2F0636920021193.do%3Fcmp%3Daf-prog-books-videos-product_cj_9781449372064_%2525zp&cjsku=0636920021193" target="_top"><img src="http://akamaicovers.oreilly.com/images/0636920021193/cat.gif" border="0" alt="Beginning NFC"/></a><img src="http://www.ftjcfx.com/image-7835726-11260198-1430755877000" width="1" height="1" border="0"/>

License
================

The MIT License

Copyright (c) 2011-2020 Chariot Solutions

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in
all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
THE SOFTWARE.