Ionic - Print receipt with thermal printer through LAN/WiFi

To print a receipt with a thermal printer through LAN/WiFi in an Ionic app, you can use a plugin that provides access to the printer capabilities of the underlying platform. For this purpose, you can use the "cordova-plugin-printer" plugin, which works with both Android and iOS platforms.

Here are the steps to achieve receipt printing in your Ionic app:

1. Install the Cordova Printer Plugin: In your Ionic project, install the "cordova-plugin-printer" plugin using the following command:

   bashCopy code
   ionic cordova plugin add cordova-plugin-printer
   

2. Add Platform-specific Printer Scripts: In the root folder of your Ionic project, navigate to the "www" folder. Here, you can create two separate JavaScript files for printing on Android and iOS platforms.

   For Android: Create a file named printer-android.js and add the following code:

   javascriptCopy code
   var printData = {
     'type': 'text', // For text printing
     'data': 'Your receipt data goes here', // Replace this with your receipt content
   };
   
   cordova.plugins.printer.print(printData);
   

   For iOS: Create a file named printer-ios.js and add the following code:

   javascriptCopy code
   var printData = {
     'name': 'Print',
     'printerId': 'com.apple.UIKit.printing.PKPrintSettingsJobTitle', // You can try different printerId values based on your printer
     'data': 'Your receipt data goes here', // Replace this with your receipt content
   };
   
   cordova.plugins.printer.print(printData);
   

3. Print Trigger from Ionic App: In your Ionic app, you can create a button or a function that triggers the printing process. For example, you can add a button in your HTML template and call a function that includes the platform-specific printer script.

   htmlCopy code
   <!-- app.component.html -->
   <ion-content>
     <ion-button (click)="printReceipt()">Print Receipt</ion-button>
   </ion-content>
   

   typescriptCopy code
   // app.component.ts
   import { Component } from '@angular/core';
   
   declare var cordova: any; // Declare cordova to use the plugin
   
   @Component({
     selector: 'app-root',
     templateUrl: 'app.component.html',
     styleUrls: ['app.component.scss'],
   })
   export class AppComponent {
     printReceipt() {
       if (window.cordova) {
         if (this.isAndroid()) {
           this.printReceiptAndroid();
         } else if (this.isIOS()) {
           this.printReceiptIOS();
         }
       }
     }
   
     isAndroid() {
       return /android/i.test(navigator.userAgent);
     }
   
     isIOS() {
       return /iPad|iPhone|iPod/.test(navigator.userAgent) && !window.MSStream;
     }
   
     printReceiptAndroid() {
       // Load the platform-specific printer script for Android
       const script = document.createElement('script');
       script.src = 'assets/printer-android.js'; // Adjust the path based on your file location
       document.body.appendChild(script);
     }
   
     printReceiptIOS() {
       // Load the platform-specific printer script for iOS
       const script = document.createElement('script');
       script.src = 'assets/printer-ios.js'; // Adjust the path based on your file location
       document.body.appendChild(script);
     }
   }
   

4. Platform-specific Configuration: Make sure to configure your thermal printer correctly and ensure that it is connected to the same network as your device. On Android, the "cordova-plugin-printer" should work out of the box. For iOS, the print behavior may depend on the printer's compatibility and configuration.

Remember to replace 'Your receipt data goes here' with the actual receipt content that you want to print.

With these steps, your Ionic app should now be able to print receipts using a thermal printer connected over LAN/WiFi. However, keep in mind that the printing capabilities depend on the printer model and the support provided by the "cordova-plugin-printer" plugin for your specific platform.