This is an library that allows you to print to a receipt printer using the system printer driver.
npm install @deniz073/system-receipt-printerReceiptPrinterEncoder library for this. You end up with an array of raw bytes that needs to be send to the printer. One way to do that is using the system printer driver.
npm install @point-of-sale/system-receipt-printer --save
`
In your project you can then import it, if you use ES6 modules:
`js
import SystemReceiptPrinter from '@point-of-sale/system-receipt-printer';
let receiptPrinter = new SystemReceiptPrinter();
`
Or require it, if you are using CommonJS:
`js
let SystemReceiptPrinter = require('@point-of-sale/system-receipt-printer');
let receiptPrinter = new SystemReceiptPrinter();
`
Configuration
When you create the SystemReceiptPrinter object you can specify a number of options to help with the library with connecting to the device.
$3
When a printer is connected to your system, it will get assigned a unique name. Provide that name when you instantiate the SystemReceiptPrinter object:
- name
The name of the printer.
For example, to print on the printer Star_TSP143__STR_T_001_:
`js
const receiptPrinter = new SystemReceiptPrinter({
name: 'Star_TSP143__STR_T_001_'
});
`
Connect to a receipt printer
The actually connect to the printer you need to call the connect() function. To find out when a receipt printer is connected you can listen for the connected event using the addEventListener() function.
`js
receiptPrinter.addEventListener('connected', device => {
console.log(Connected to printer);
});
`
The callback of the connected event is passed an object with the following properties:
- type
Type of the connection that is used, in this case it is always system.
Commands
Once connected you can use the following command to print receipts.
$3
When you want to print a receipt, you can call the print() function with an array, or a typed array with bytes. The data must be properly encoded for the printer.
For example:
`js
/ Encode the receipt /
let encoder = new ReceiptPrinterEncoder({
language: 'esc-pos',
codepageMapping: 'epson'
});
let data = encoder
.initialize()
.text('The quick brown fox jumps over the lazy dog')
.newline()
.qrcode('https://nielsleenheer.com')
.encode();
/ Print the receipt /
receiptPrinter.print(data);
`
$3
When you are done with printing, you can call the disconnect() function. This will terminate the connection to the printer. If the connection to the printer is closed, the library will emit a disconnected event.
`js
receiptPrinter.addEventListener('disconnected', () => {
console.log(Disconnected from the printer);
});
receiptPrinter.disconnect();
`
$3
The SystemReceiptPrinter object has a static function that you can call to get a list of all printers that are available on your system:
`js
let printers = SystemReceiptPrinter.getPrinters();
[
{
name: 'Star_TSP143__STR_T_001_',
isDefault: false,
options: { ... },
status: 'IDLE'
},
{
name: 'Star_TSP654__STR_T_001_',
isDefault: false,
options: { ... },
status: 'IDLE'
}
]
``