feat(pos): add real thermal ticket printing via ESC/POS (#21)
- Add thermal_printer.py service generating raw ESC/POS bytes for 58mm/80mm printers - Add /pos/api/sales/<id>/print endpoint (escpos_raw or browser mode) - Add printer.js with WebUSB and Web Serial support for direct browser-to-printer - Add thermal print button in ticket modal with connect/print workflow Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
This commit is contained in:
@@ -26,7 +26,11 @@ const POS = (() => {
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let searchTimeout = null;
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let customerSearchTimeout = null;
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const fmt = (n) => '$' + parseFloat(n || 0).toLocaleString('es-MX', { minimumFractionDigits: 2, maximumFractionDigits: 2 });
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// Currency-aware formatter: reads pos_currency from localStorage
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const _posCurrency = localStorage.getItem('pos_currency') || 'MXN';
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const _currSymbols = { MXN: '$', USD: 'US$' };
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const _currLocale = _posCurrency === 'USD' ? 'en-US' : 'es-MX';
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const fmt = (n) => (_currSymbols[_posCurrency] || '$') + parseFloat(n || 0).toLocaleString(_currLocale, { minimumFractionDigits: 2, maximumFractionDigits: 2 });
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function headers() {
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return { 'Content-Type': 'application/json', 'Authorization': 'Bearer ' + token };
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@@ -940,6 +944,45 @@ const POS = (() => {
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setTimeout(() => { if (area) area.style.display = 'none'; }, 500);
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}
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// ─── Thermal Printing ─────────────────
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async function connectThermal() {
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if (!window.NexusPrinter) { showToast('Printer module not loaded'); return; }
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const result = await NexusPrinter.connect();
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if (result.ok) {
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showToast('Impresora conectada: ' + (result.name || result.type));
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_updatePrinterButtons();
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} else {
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showToast(result.error || 'No se pudo conectar la impresora');
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}
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}
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async function thermalPrint() {
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if (!window.NexusPrinter || !NexusPrinter.isConnected()) {
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showToast('Conecte una impresora termica primero');
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return;
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}
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if (!lastSaleId) { showToast('No hay venta para imprimir'); return; }
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const ok = await NexusPrinter.printSale(lastSaleId);
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if (ok) {
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showToast('Ticket enviado a impresora termica');
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} else {
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showToast('Error al imprimir. Reconecte la impresora.');
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}
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}
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function _updatePrinterButtons() {
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const connectBtn = document.getElementById('btnConnectPrinter');
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const thermalBtn = document.getElementById('btnThermalPrint');
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if (window.NexusPrinter && NexusPrinter.isConnected()) {
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if (connectBtn) connectBtn.style.display = 'none';
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if (thermalBtn) thermalBtn.style.display = '';
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} else {
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if (connectBtn) connectBtn.style.display = '';
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if (thermalBtn) thermalBtn.style.display = 'none';
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}
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}
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// ─── Last Sale ───────────────────────
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async function showLastSale() {
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if (!lastSaleId) { showToast('No hay venta reciente'); return; }
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@@ -1078,5 +1121,6 @@ const POS = (() => {
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creditSale, saveQuotation, createLayaway,
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showLastSale, openDrawer,
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showTicket, closeTicketModal, printTicket,
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connectThermal, thermalPrint,
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};
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})();
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152
pos/static/js/printer.js
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152
pos/static/js/printer.js
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@@ -0,0 +1,152 @@
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/**
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* NexusPrinter — Web USB / Web Serial bridge for thermal printers.
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*
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* Connects to 58mm or 80mm ESC/POS printers via WebUSB or Web Serial APIs
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* and sends raw byte commands generated by the backend.
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*/
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window.NexusPrinter = (function () {
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'use strict';
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let _device = null; // WebUSB device
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let _endpoint = null; // USB bulk-out endpoint number
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let _serialPort = null; // Web Serial port
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let _writer = null; // Serial writable stream writer
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let _type = null; // 'usb' | 'serial' | null
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// ── Connection ─────────────────────────────────
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async function connect() {
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// Try WebUSB first
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if ('usb' in navigator) {
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try {
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_device = await navigator.usb.requestDevice({ filters: [] });
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await _device.open();
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// Select first configuration if needed
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if (_device.configuration === null) {
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await _device.selectConfiguration(1);
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}
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// Claim first interface and find bulk-out endpoint
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const iface = _device.configuration.interfaces[0];
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await _device.claimInterface(iface.interfaceNumber);
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const alt = iface.alternates[0];
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const ep = alt.endpoints.find(e => e.direction === 'out' && e.type === 'bulk');
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if (ep) {
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_endpoint = ep.endpointNumber;
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_type = 'usb';
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_save();
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return { ok: true, type: 'usb', name: _device.productName || 'USB Printer' };
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}
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} catch (e) {
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// User cancelled or no USB device available
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_device = null;
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}
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}
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// Fall back to Web Serial
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if ('serial' in navigator) {
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try {
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_serialPort = await navigator.serial.requestPort();
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await _serialPort.open({ baudRate: 9600 });
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_writer = _serialPort.writable.getWriter();
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_type = 'serial';
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_save();
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return { ok: true, type: 'serial', name: 'Serial Printer' };
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} catch (e) {
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_serialPort = null;
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_writer = null;
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}
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}
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return { ok: false, error: 'No printer connected. Use a browser that supports WebUSB or Web Serial (Chrome/Edge).' };
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}
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async function disconnect() {
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try {
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if (_type === 'usb' && _device) {
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await _device.close();
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}
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if (_type === 'serial') {
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if (_writer) { _writer.releaseLock(); _writer = null; }
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if (_serialPort) { await _serialPort.close(); _serialPort = null; }
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}
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} catch (e) { /* ignore */ }
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_device = null;
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_endpoint = null;
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_type = null;
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localStorage.removeItem('nexus_printer');
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}
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function isConnected() {
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return _type !== null;
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}
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// ── Printing ───────────────────────────────────
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async function sendRaw(bytes) {
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if (!_type) return false;
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try {
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if (_type === 'usb' && _device && _endpoint !== null) {
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// Send in chunks of 512 bytes (common USB max packet size)
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const chunk = 512;
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for (let i = 0; i < bytes.length; i += chunk) {
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await _device.transferOut(_endpoint, bytes.slice(i, i + chunk));
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}
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return true;
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}
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if (_type === 'serial' && _writer) {
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await _writer.write(bytes);
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return true;
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}
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} catch (e) {
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console.error('[NexusPrinter] send error:', e);
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// Connection likely lost
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await disconnect();
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}
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return false;
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}
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/**
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* Print a sale ticket by fetching ESC/POS bytes from the backend.
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* @param {number} saleId
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* @param {number} [width=80] — 58 or 80 mm
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* @returns {Promise<boolean>}
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*/
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async function printSale(saleId, width) {
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width = width || 80;
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const token = localStorage.getItem('pos_token');
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const resp = await fetch('/pos/api/sales/' + saleId + '/print', {
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method: 'POST',
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headers: {
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'Authorization': 'Bearer ' + token,
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'Content-Type': 'application/json'
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},
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body: JSON.stringify({ printer_type: 'escpos_raw', width: width })
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});
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if (!resp.ok) {
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console.error('[NexusPrinter] backend error', resp.status);
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return false;
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}
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const buf = await resp.arrayBuffer();
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return sendRaw(new Uint8Array(buf));
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}
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// ── Persistence helpers ────────────────────────
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function _save() {
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try { localStorage.setItem('nexus_printer', _type || ''); } catch (e) {}
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}
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// ── Public API ─────────────────────────────────
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return {
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connect: connect,
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disconnect: disconnect,
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isConnected: isConnected,
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sendRaw: sendRaw,
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printSale: printSale
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};
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})();
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