ean-epc/epc/epc.js

EPC Tag Data Standard encoding and decoding library, written in javascript

/*
 * EPC Tag Data Standard
 * 2021 Sergio S. - https://github.com/sergiss/epc-tds
 */

import { BitArray } from './utils/bit-array';

export class Epc extends BitArray {
  constructor(length) {
    super(length);
  }

  clone() {
    throw new Error('Unimplemented method.');
  }

  getType() {
    throw new Error('Unimplemented method.');
  }

  toTagURI() {
    throw new Error('Unimplemented method.');
  }

  toIdURI() {
    throw new Error('Unimplemented method.');
  }

  toBarcode() {
    throw new Error('Unimplemented method.');
  }

  getTotalBits() {
    throw new Error('Unimplemented method.');
  }

  getHeader() {
    throw new Error('Unimplemented method.');
  }

  /**
   * The filter value is additional control information that may be included in
   * the EPC memory bank of a Gen 2 tag. The intended use of the filter value is
   * to allow an RFID reader to select or deselect the tags corresponding to
   * certain physical objects, to make it easier to read the desired tags in an
   * environment where there may be other tags present in the environment
   * @return
   */
  getFilter() {
    return super.get(Epc.FILTER_OFFSET, Epc.FILTER_END);
  }

  /**
   * 0.- All Others (see Section 10.1).
   * 1.- Point of Sale (POS) Trade Item .
   * 2.- Full Case for Transport.
   * 3.- Reserved (see Section 10.1).
   * 4.- Inner Pack Trade Item Grouping for Handling.
   * 5.- Reserved (see Section 10.1).
   * 6.- Unit Load.
   * 7.- Unit inside Trade Item or component inside a
   *     product not intended for individual sale.
   * @param value
   */
  setFilter(value) {
    if (value < 0 || value > Epc.FILTER_MAX_VALUE) {
      throw new Error(
        `Value '${value}' out of range (min: 0, max: ${Epc.FILTER_MAX_VALUE})`,
      );
    }
    super.set(value, Epc.FILTER_OFFSET, Epc.FILTER_END);
    return this;
  }

  getSegment(segment) {
    return super.get(segment.start, segment.end);
  }

  setSegment(value, segment) {
    if (value < 0 || value > segment.maxValue) {
      throw new Error(`Value '${value}' out of range (min: 0, max: ${segment.maxValue})`);
    }
    super.set(value, segment.start, segment.end);
  }

  getSegmentString(segment) {
    return String(this.getSegment(segment)).padStart(segment.digits, '0');
  }
}

Epc.EPC_HEADER_OFFSET = 0;
Epc.EPC_HEADER_END = 8;
Epc.FILTER_OFFSET = 8;
Epc.FILTER_END = 11;
Epc.FILTER_MAX_VALUE = 7;