Can't read empty tags

[joshdillner]

Hi, I've been implementing the latest API and testing on Chrome Canary, and I've found that I can't scan empty tags - it never enters the "onreading" or "onerror" event.

I've also found that writing a url record type seems to add 2 records: Record 0, type = URI record Record 1, type = w3.org:a

Can you advise? Here's my code:

(async () => {
  this.setState({ error: { message: "ready to scan" } });

  await reader.scan({ signal: controller.signal });

  reader.onreading = event => {
    this.setState({ error: { message: "found tag, starting write" } });

    const writer = new NDEFWriter();

    writer
      .push({
        records: [
          {
            recordType: "url",
            data: `https://www.google.com`
          }
        ]
      })
      .then(() => {
        this.setState({
          writing: false,
          writeResult: "success",
          error: { message: "write success" }
        });
        controller.abort();
      })
      .catch(e => {
        this.setState({
          writing: false,
          writeResult: "fail",
          error: { ...e, message: "writing failed, try again" }
        });
        controller.abort();
      });
  };

  reader.onerror = event => {
    this.setState({ error: { message: "scanning error" } });
  };
})();

[beaufortfrancois]

Is your empty tag NDEF formatted? If not, this may explain why you don't receive any event. If so, you should receive an "onreading" event with one "empty" message. See https://chromiumdash.appspot.com/commit/645a24e453cbb8767c7684527c48359b23ecac1f Make sure you use latest Chrome Canary on Android.

Regarding the second record, this happen because previous version of the Web NFC spec included a "special" record when writing from Web NFC. This is no longer the case and will be removed from the Chromium implementation.

[beaufortfrancois]

Please re-open if you're still having issues.