/phonegap-nfc

PhoneGap NFC Plugin

Primary LanguageJava

PhoneGap NFC Plugin

The PhoneGap NFC Plugin provides access to Near Field Communication (NFC) functionality, allowing applications to read NDEF message in NFC tags. A "tag" may actually be another device that appears as a tag.

Supported Platforms

  • Android
  • BlackBerry 7
  • BlackBerry 10
  • Windows Phone 8

Contents

Installing

See INSTALL.md for details on how to install the nfc-plugin into your PhoneGap project.

PhoneGap 2.2.0 or greater is required. PhoneGap 2.4.0 is recommended.

NFC

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

Methods

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
  • BlackBerry 7

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.

Supported Platforms

  • Android
  • BlackBerry 7

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 occurs when a NDEF tag is read.

NOTE: Registered mimeTypeListeners takes precedence over the more generic NDEF listener.

Supported Platforms

  • Android
  • BlackBerry 7
  • BlackBerry 10
  • Windows Phone 8

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 ndefRecord = ndef.textRecord("Hello World"),
	ndefMessage = [];

ndefMessage.push();

nfc.write(ndefMessage, [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.

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

Supported Platforms

  • Android
  • BlackBerry 7
  • Windows Phone 8

nfc.share

Shares an NDEF Message via peer-to-peer.

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

var ndefRecord = ndef.textRecord("Hello World"),
	ndefMessage = [];

ndefMessage.push();

nfc.share(ndefMessage, [onSuccess], [onFailure]);

Parameters

  • ndefMessage: An array of NDEF Records.
  • onSuccess: (Optional) The callback that is called when the message is pushed.
  • onFailure: (Optional) The callback that is called if there was an error.

Description

Function nfc.share writes an NdefMessage via peer-to-peer. This should appear as an NFC tag to another device.

Supported Platforms

  • Android
  • BlackBerry 7
  • Windows Phone 8

nfc.unshare

Stop sharing NDEF data via peer-to-peer.

nfc.unshare([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.unshare stops sharing data via peer-to-peer.

Supported Platforms

  • Android
  • BlackBerry 7

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
  • BlackBerry 7

NDEF

The ndef object provides NDEF constants, functions for creating NdefRecords, and functions for converting data. See android.nfc.NdefRecord 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 = ndef.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();

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 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 techTypes may be included when scanning a tag on Android. serialNumber may be included on BlackBerry.

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

Windows Phone 8 and BlackBerry 10 read the NDEF information from a tag, but do not have access to the tag id or other meta data like capacity, read-only status or tag technologies.

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
        }]
    }
}

Sample Event on BlackBerry 7

{
    type: 'ndef',
    tag: {
        "tagType": "4",
        "isLocked": false,
        "isLockable": false,
        "freeSpaceSize": "2022",
        "serialNumberLength": "7",
        "serialNumber": [4, 96, 117, 74, -17, 34, -128],
        "name": "Desfire EV1 2K",
        "ndefMessage": [{
            "tnf": 2,
            "type": [116, 101, 120, 116, 47, 112, 103],
            "id": [],
            "payload": [72, 101, 108, 108, 111, 32, 80, 104, 111, 110, 101, 71, 97, 112]
        }]
    }
}

Sample Event on BlackBerry 10 or Windows Phone 8

{
    type: 'ndef',
    tag: {
        "ndefMessage": [{
            "tnf": 2,
            "type": [116, 101, 120, 116, 47, 112, 103],
            "id": [],
            "payload": [72, 101, 108, 108, 111, 32, 80, 104, 111, 110, 101, 71, 97, 112]
        }]
    }
}

Getting Details about Events

The raw contents of the scanned tags are written to the log before the event is fired. Use adb logcat on Android and Event Log (hold alt + lglg) on BlackBerry.

You can also log the tag contents in your event handlers. console.log(JSON.stringify(nfcEvent.tag)) Note that you want to stringify the tag not the event to avoid a circular reference.

Platform Differences

Non-NDEF Tags

Only Android and BlackBerry 7 can read Non-NDEF NFC tags.

Mifare Classic Tags

BlackBerry 7 and BlackBerry 10 will not read Mifare Classic tags. Mifare Ultralight tags will work since they are NFC Forum Type 2 tags.

Tag Id and Meta Data

Windows Phone 8 and BlackBerry 10 read the NDEF information from a tag, but do not have access to the tag id or other meta data like capacity, read-only status or tag technologies.

Multiple Listeners

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

On Android, only the most specific event will fire. If a Mime Media Tag is scanned, only the addMimeTypeListener callback is called.

On BlackBerry 10, all the events fire if a Mime Media Tag is scanned.

addTagDiscoveredListener on Android and BlackBerry 7.

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.

On BlackBerry 7, addTagDiscoveredListener does NOT scan non-NDEF tags. Webworks returns the ndefMessage in the event.

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"]
    }
}

Launching your 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.

Sample Projects

License

The MIT License

Copyright (c) 2011-2012 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.