NDEFReader: reading event

Secure contextLimited availability

The reading event of the NDEFReader interface is fired whenever a new reading is available from compatible NFC devices (e.g., NFC tags supporting NDEF) when these devices are within the reader’s magnetic induction field.

Syntax

Use the event name in methods like addEventListener(), or set an event handler property.

addEventListener("reading", (event) => { })

onreading = (event) => { }

Event type

A generic Event.

Examples

The following example shows how to process events using both the onreading and onreadingerror event handlers.

const ndef = new NDEFReader();
ndef
  .scan()
  .then(() => {
    console.log("Scan started successfully.");
    ndef.onreadingerror = (event) => {
      console.log(
        "Error! Cannot read data from the NFC tag. Try a different one?",
      );
    };
    ndef.onreading = (event) => {
      console.log("NDEF message read.");
    };
  })
  .catch((error) => {
    console.log(`Error! Scan failed to start: ${error}.`);
  });

Specifications

Browser compatibility

See also

• readingerror event