Android system NFC framework introduction and develop guide

TNF_EXTERNAL_TYPE

Given the following TNF_EXTERNAL_TYPE NDEF record, which is stored as the first record inside of an NdefMessage:

the intent filter would look like this:

Use TNF_EXTERNAL_TYPE for more generic NFC tag deployments to better support both Android-powered and non-Android-powered devices.

Note: URNs for TNF_EXTERNAL_TYPE have a canonical format of:

urn:nfc:ext::externalType, however the NFC Forum RTD

specification declares that the urn:nfc:ext: portion of the URN must be ommitted

from the NDEF record. So all you need to provide is the domain ( in the

example) and type (externalType in the example) separated by a colon. When

dispatching TNF_EXTERNAL_TYPE, Android converts the

urn:nfc:ext::externalType URN to a

vnd.android.nfc://ext/:externalType URI, which is what the

intent filter in the example declares.