How to format a tag when tag is formatable

[rajvaida]

The card I am reading is not pre-formated. But it's NdefFormatable is in techTypes. How to format and get tag data/Payload?

I am not planning to write anything back to card.

[don]

Use nfc.addNdefFormatableListener (or perhaps nfc.addTagDiscoveredListener.)

You can read the tag meta data when it's discovered. There's no payload when you use nfc.addNdefFormatableListener or nfc.addTagDiscoveredListener.

To format the tag, use nfc.write and write an empty message onto the tag.

// This code belongs in the success callback for nfc.addNdefFormatableListener
// write an empty NDEF record to format the tag
var message = [
    ndef.emptyRecord();
];

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

[rajvaida]

Thank you. I am trying to implement something similar to https://github.com/codebutler/farebot

[don]

It looks like farebot reads the raw bytes from the NFC tags. This plugin can only read NDEF messages. If you want to support the same cards as farebot, you're probably better off creating a new plugin that wraps the farebot code (assuming you're OK with GPL.). The plugin could send the card XML to javascript for processing.

[lughino]

Hi @don, I have a problem to format a ndef-formatable tag with the procedure you described. Every time I try to write the error callback is called with the argument error to null. I tried to write a card with an external application (NXP TagWrite) and is written correctly. After having written the card is properly recognized by your plugin through addNdefListener and I can read and write. This is the code that I use to test the writing:

window.nfc.addNdefFormatableListener(
        function(nfcData) {
          console.log('data in formatable', nfcData);
          window.nfc.write([
              window.ndef.emptyRecord()
            ],
            function(d) {
              console.log('success', d);
            },
            function(e) {
              console.log('error', e, arguments); // this is always null
            }
          );
        },
        function() {
          console.log('listen nfc formatable');
        },
        function(err) {
          console.log(err);
        }
      );

This is the content of the card:

{
bubbles: false,
cancelBubble: false,
cancelable: false,
clipboardData: undefined,
currentTarget: null,
defaultPrevented: false,
eventPhase: 0,
returnValue: true,
srcElement: document,
tag: {
  id: [4, 94, -71, -54, -87, 74, -127],
  techTypes: ["android.nfc.tech.MifareUltralight", "android.nfc.tech.NfcA", ]
},
target: document,
timeStamp: 1478188522177,
type: "ndef-formatable"
}

How can I fix the problem? Thank you

[RicardoLopes91]

Hi @don

I have the same problem as @Lughino. Is there any way to solve this?

Thank you.