PromptParse

You can use PromptParse directly in a web browser by including the library via a CDN script tag. The library is exposed under the global promptparse object. For example, you can access promptparse.generate to create payloads for various services like TrueMoney.

<script src="https://cdn.jsdelivr.net/npm/promptparse"></script>

<script>
  ;(function () {
    // Generate QR code payload (use function from "promptparse" global)
    const payload = promptparse.generate.trueMoney({
      mobileNo: '08xxxxxxxx',
      amount: 10.0,
      message: 'Hello World!',
    })

    // Quick & dirty way to show QR Code image
    document.write(
      `<img src="https://api.qrserver.com/v1/create-qr-code/?size=300x300&data=${payload}">`,
    )
  })()
</script>

Use the billPayment function from the promptparse/generate sub-module to create a payload for PromptPay Bill Payment QR codes. This is useful for generating data that can then be converted into a visual QR code image.

import { billPayment } from 'promptparse/generate'

const payload = billPayment({
  billerId: '1xxxxxxxxxxxx',
  amount: 300.0,
  ref1: 'INV12345',
})

// TODO: Create QR Code from payload

Use the parse function to convert a raw QR Code data string into a parseable object. Once parsed, you can retrieve specific values using the getTagValue(tagId) method, where tagId is the string identifier for the tag (e.g., '00').

import { parse } from 'promptparse'

// Example data
const ppqr = parse('000201010211...')

// Get Value of Tag ID '00'
ppqr.getTagValue('00') // Returns '01'

Use parseBarcode to parse a Bank of Thailand (BOT) standard barcode string. If the barcode is valid, you can call the .toQrTag30() method on the resulting object to convert the barcode data into a PromptPay QR Tag 30 (Bill Payment) payload.

import { parseBarcode } from 'promptparse'

const botBarcode = parseBarcode('|310109999999901\r...')

if (!botBarcode) {
  console.error('Invalid Payload')
}

const payload = botBarcode.toQrTag30()

// TODO: Create QR Code from payload

Use the slipVerify function from promptparse/validate to validate the checksum and structure of a Slip Verify (Mini QR) payload. If the payload is valid, it returns an object containing transaction details like sendingBank and transRef. If invalid, it returns null or undefined.

import { slipVerify } from 'promptparse/validate'

const data = slipVerify('00550006000001...')

if (!data) {
  console.error('Invalid Payload')
}

const { sendingBank, transRef } = data

// TODO: Inquiry transaction from Bank Open API

To construct a raw QR data string from scratch, use tag(id, value) to create individual tag segments and encode(data) to combine them. To ensure the string is valid for scanners, use withCrcTag(encodedData, crcTagId) to append the checksum (typically using tag ID '63').

import { encode, tag, withCrcTag } from 'promptparse'

// Example data
const data = [
  tag('00', '01'),
  tag('01', '11'),
  // ...
]

// Set CRC Tag ID '63'
withCrcTag(encode(data), '63') // Returns '000201010211...'

Use the encode function to convert an array of TLVTag objects back into a single TLV-encoded string. This function supports nested tags via the subTags property.

import { encode, tag } from '@/lib/tlv';

const tags = [
  tag('01', 'VAL1'),
  tag('02', 'VAL2')
];
const payload = encode(tags);
// Result: '0104VAL10204VAL2'

Use the parseBarcode function to parse barcode data strings that follow the BOT (Bank of Thailand) Barcode Standard. It returns a BOTBarcode instance.

Parameters:

• payload (string): The raw barcode data string from the scanner.

import { parseBarcode } from 'promptparse';

const barcode = parseBarcode('01021234567890123456');

The withCrcTag function takes an existing TLV payload and appends a CRC tag. It calculates the checksum of the payload (including the new CRC tag ID and length) and appends the resulting checksum value.

Parameters:

• payload: The original TLV string.
• crcTagId: The 2-character ID to use for the CRC tag.
• upperCase: Whether to return the checksum in uppercase (default: true).

import { withCrcTag } from '@/lib/tlv';

const payload = '0105HELLO';
const securePayload = withCrcTag(payload, '99');
// Result: '0105HELLO9904XXXX' where XXXX is the checksum

The validate namespace provides utilities for validating and extracting data from existing QR codes, such as Slip Verify QRs.

import { validate } from 'promptparse';

The checksum function generates a CRC16-XMODEM checksum for a given string. The result is a 4-character hex string. You can control whether the output is uppercase or lowercase using the upperCase option (defaults to true).

import { checksum } from '@/lib/tlv';

const crc = checksum('some-payload');
// Returns 4-character hex string, e.g., 'A1B2'