🖨️ Printer Service Node Package

A lightweight, robust, and developer-friendly Vue 3 composable package to handle local printer integrations smoothly. Perfect for Point of Sale (POS) systems, thermal receipt printers, and automated waybill/invoice printing workflows.

[!IMPORTANT] Desktop App Required: To use this package, you must download and run the PrintBridge desktop application from https://premod.me/printbridge.

✨ Features

• 🔌 Zero Configuration Connection: Connect to the local PrintBridge hardware server queue effortlessly.
• 🖨️ Thermal & HTML Printing: Send raw or styled HTML templates directly to thermal/receipt printers (supporting default 80mm and custom widths).
• 🚦 Real-time Status Monitoring: Check printer availability, connection health, and queue status reactively using Vue refs.
• 🛡️ Production Ready: Built-in timeout setups, automated error catch handling, and detailed logs to prevent queue blocking.

📦 Installation

Install the package via NPM:

npm install printer-service-package

Quick Start

Here is a simple example showing how to fetch available printers, select one, and print an HTML document from a Vue 3 component (using <script setup>):

<template>
  <div class="printer-card">
    <h3>🖨️ Print Terminal</h3>

    <!-- Fetch printers button -->
    <button @click="loadPrinters" :disabled="isChecking">
      {{ isChecking ? 'Checking connection...' : 'Refresh Printer List' }}
    </button>

    <!-- Printer selection dropdown -->
    <div v-if="printers.length > 0" class="controls">
      <select v-model="selectedPrinter">
        <option disabled value="">Select local printer</option>
        <option v-for="printer in printers" :key="printer.name" :value="printer.name">
          {{ printer.name }}
        </option>
      </select>

      <!-- Print action -->
      <button @click="handlePrint" :disabled="!selectedPrinter">
        Print Test Page
      </button>
    </div>

    <!-- Live Status / Error logs -->
    <div v-if="isConnected" class="badge online">Print Server Online</div>
    <div v-else class="badge offline">Print Server Offline</div>
    
    <p v-if="lastError" class="error-text">{{ lastError }}</p>
  </div>
</template>

<script setup>
import { ref } from 'vue'
import { useLocalPrinterService } from 'printer-service-package'

// Initialize the composable
const { 
  printers, 
  isConnected, 
  isChecking, 
  lastError, 
  getPrinters, 
  printHTML 
} = useLocalPrinterService({
  port: '8080',   // Port of local PrintBridge service (default: 8080)
  timeout: 5000   // Request timeout limit (default: 5000ms)
})

const selectedPrinter = ref('')

const loadPrinters = async () => {
  await getPrinters()
}

const handlePrint = async () => {
  if (!selectedPrinter.value) return
  try {
    const htmlReceipt = '<h1>Invoice #1024</h1><p>Thank you for your purchase!</p>'
    await printHTML(selectedPrinter.value, htmlReceipt, '80mm')
    alert('Print job successfully queued!')
  } catch (error) {
    alert('Print failed: ' + error.message)
  }
}
</script>

<style scoped>
.printer-card { padding: 16px; border: 1px solid #eaeaea; border-radius: 8px; }
.controls { margin: 12px 0; display: flex; gap: 8px; }
.badge { display: inline-block; padding: 4px 8px; border-radius: 4px; font-size: 12px; color: white; }
.online { background: #4caf50; }
.offline { background: #f44336; }
.error-text { color: #f44336; font-size: 13px; margin-top: 8px; }
</style>

🛠️ API Reference

useLocalPrinterService(options)

Hook to control the local printing service. Accepts an optional configuration object:

• port (string, default: '8080'): The port of the local PrintBridge app.
• baseUrl (string): Complete custom URL (overrides port).
• timeout (number, default: 5000): Connection timeout in milliseconds.

State (Reactive Ref Values)

• isConnected (Ref): true if the local PrintBridge service responds to queries.
• isChecking (Ref): true while the service state is being verified.
• printers (Ref): A list of available local printer objects (e.g. [{ name: 'Epson_TM_T88' }]).
• lastError (Ref): Contains details of the last failed request.

Methods

• checkConnection(): Verifies if the desktop client is running. Returns Promise<boolean>.
• getPrinters(): Updates and returns the list of available system printers. Returns Promise<array>.
• printHTML(printerName, htmlContent, width): Sends an HTML payload with the specified width (default: '80mm') to the local print queue. Returns Promise<any>.

📄 License

This project is licensed under the MIT License - see the LICENSE file for details.