How can I parse following wifi ndef record? I old library we could do it following manner
data = bytearray("\x10J\x00\x01\x10\x10\x0e\x002\x10&\x00\x01\x01\x10E\x00\x04Wxyz\x10\x03\x00\x02\x00\x01\x10\x0f\x00\x02\x00\x01\x10'\x00\x0bAbcdefg1234\x10 \x00\x06\xff\xff\xff\xff\xff\xff")
record = nfc.ndef.Record('application/vnd.wfa.wsc', '1', data)
print nfc.ndef.WifiConfigRecord(record).pretty()

Hi, I am using python 3.10, and using this package.
I am following the instructions on webpage , but when I executed decoder = ndef.message_decoder(octets), it says:

>>> decoder = ndef.message_decoder(octets)
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: module 'ndef' has no attribute 'message_decoder'

Is it a bug?

Hi

https://github.com/haldean/ndef/blob/master/docs/NFCForum-TS-Signature_RTD-1.0.pdf

here the specification

here: 3028b2a i see change from byte to word. I don't have v2.0 specification but as for v.1 (or as in the decoder v0.1) here byte lengths.

i can modify the current Signature class to support v1 and v2 cases. Is this ok?

In order to support strict error reporting for NDEF data encoding, ndeflib exposes two helper methods: message_decoder and message_encoder (see https://nfcpy.readthedocs.io/en/latest/modules/tag.html#nfc.tag.Tag.NDEF.records and https://ndeflib.readthedocs.io/en/stable/ndef.html#message-encoder) for more info.

In the docs, the example code is as follows:

from ndef import message_decoder, message_encoder
records = message_decoder(tag.ndef.octets, errors='strict')
octets = b''.join(message_encoder(records, errors='strict'))
tag.ndef.octets = octets

However, message_encoder does not accept the keyword arg errors. Thus I have a few questions for @nehpetsde:

1. Should / can message_encoder accept this keyword argument? Has this just yet to be implemented?

2. Should message_encoder not support this keyword argument? If so, what limitations are associated with encoding that would mean it is not possible to support this?

3. In the meantime, would you like me to create pull request updating the docs?

Error output:

  File "tool.py", line 41, in <module>
    ret = clf.connect(rdwr=config)
  File "/usr/local/lib/python2.7/dist-packages/nfc/clf/__init__.py", line 580, in connect
    result = self._rdwr_connect(rdwr_options, terminate)
  File "/usr/local/lib/python2.7/dist-packages/nfc/clf/__init__.py", line 611, in _rdwr_connect
    if options['on-connect'](tag):
  File "tool.py", line 17, in on_connect
    octets = b''.join(message_encoder([rec], errors='strict'))
TypeError: message_encoder() got an unexpected keyword argument 'errors'

Platform:

pi@raspberrypi:~ $ uname -a
Linux raspberrypi 4.4.50-v7+ #970 SMP Mon Feb 20 19:18:29 GMT 2017 armv7l GNU/Linux

pi@raspberrypi:~ $ cat /etc/os-release
PRETTY_NAME="Raspbian GNU/Linux 8 (jessie)"
NAME="Raspbian GNU/Linux"
VERSION_ID="8"
VERSION="8 (jessie)"

Lib version:

pi@raspberrypi:~$ pip freeze
# ommited
ndeflib==0.2.0
nfcpy==0.13.2

Python version:

pi@raspberrypi:~ $ python --version
Python 2.7.9

Currently only encoded as 8-bit lengths, should be 16-bit lengths. This is causing reads to fail.

Need to change instances of B+ to H+ during encoding/decoding.

I've used ndeflib in a simple tool but ran into a problem that I hadn't expected; the message_encoder cannot be told to refrain from setting MB and ME flags. Since I wanted to concatenate individually generated outputs, this means I need to change this after encoding.

One way of doing this generically is to have an ndef_concat() function that removes MB from all but the first, and ME from all but the last. Another, much simpler way would be extra function options

def message_encoder (..., first=True, last=True):

that need to be set to False to overrule the current / default behaviour of generating MB and ME on the first and last records.