Capacitor MK Printer

A Capacitor plugin for MK printer integration.

Installation

npm install capacitor-mk-printer
npx cap sync

API

• listenPrinters()
• connectPrinter(...)
• getCurrentPrinter()
• printImage(...)
• Interfaces

listenPrinters()

listenPrinters() => Promise<{ devices: BluetoothDevice[] }>

List available printers that can be connected.

Returns: Promise<{ devices: BluetoothDevice[] }>

connectPrinter(...)

connectPrinter(options: { macAddress: string }) => Promise<any>

Connect to a printer.

| Param | Type | Description | | ------------- | ------------------------------------ | ------------------------------ | | options | { macAddress: string } | MAC address of the printer to connect |

Returns: Promise<any>

getCurrentPrinter()

getCurrentPrinter() => Promise<{ name: string; macAddress: string }>

Get information about the currently connected printer.

Returns: Promise<{ name: string; macAddress: string }>

printImage(...)

printImage(options: PrintImageOptions) => Promise<any>

Print an image.

| Param | Type | Description | | ------------- | ------------------------------------------------------------- | -------------------------- | | options | PrintImageOptions | Image printing options |

Returns: Promise<any>

Interfaces

BluetoothDevice

| Property | Type | Description | | ----------------- | ------------------- | ---------------------------------- | | name | string | Device name | | macAddress | string | Device MAC address | | type | string | Device type (optional) |

PrintImageOptions

| Property | Type | Description | |------------------| ------------------- |--------------| | base64Data | string | image base64 |

Permissions

Android

Add these permissions to your AndroidManifest.xml file:

<uses-permission android:name="android.permission.BLUETOOTH" />
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" />
<uses-permission android:name="android.permission.BLUETOOTH_CONNECT" />
<uses-permission android:name="android.permission.BLUETOOTH_SCAN" />
<uses-permission android:name="android.permission.READ_EXTERNAL_STORAGE" />
<uses-permission android:name="android.permission.WRITE_EXTERNAL_STORAGE" />

iOS

Add these permission descriptions to your Info.plist file:

<key>NSBluetoothAlwaysUsageDescription</key>
<string>This app needs Bluetooth access to connect to printers</string>
<key>NSBluetoothPeripheralUsageDescription</key>
<string>This app needs Bluetooth access to connect to printers</string>

Usage Example

import { MkPrinter } from 'capacitor-mk-printer';

// List available printers
async function scanPrinters() {
  try {
    const result = await MkPrinter.listenPrinters();
    console.log('Available printers:', result.devices);
  } catch (error) {
    console.error('Error scanning printers:', error);
  }
}

// Connect to a printer
async function connect(macAddress: string) {
  try {
    await MkPrinter.connectPrinter({ macAddress });
    console.log('Connected successfully');
  } catch (error) {
    console.error('Connection failed:', error);
  }
}

// Get current printer information
async function getCurrentPrinter() {
  try {
    const printer = await MkPrinter.getCurrentPrinter();
    console.log('Current printer:', printer);
  } catch (error) {
    console.error('Error getting current printer:', error);
  }
}

// Print an image
async function printImage(base64Data: string) {
  try {
    await MkPrinter.printImage({ base64Data });
    console.log('Image printed successfully');
  } catch (error) {
    console.error('Error printing image:', error);
  }
}

Development

Build

# In the plugin directory
npm run build          # compiles TypeScript to dist/

Publish to npm

# In the plugin directory
npm run build
npm login              # once; requires publish rights to the package
# bump the "version" field in package.json
# (npm rejects re-publishing an already-published version)
npm publish

Then, in your app:

# In the app directory
npm install capacitor-mk-printer@latest
npx cap sync android

Install locally (without publishing)

Useful for testing native changes before a release. Paths below are examples — adjust them to your machine.

# In the plugin directory
npm run build
npm pack               # creates capacitor-mk-printer-<version>.tgz

# In the app directory (point to the .tgz produced above)
npm install /path/to/capacitor-mk-printer/capacitor-mk-printer-<version>.tgz --no-save
npx cap sync android

--no-save keeps your app's package.json untouched, so it's easy to switch back to the published version with a plain npm install.

Notes

• Always run npx cap sync android after installing so Capacitor copies the updated native sources (Java + bundled .jars) into the Android project.
• Build the Android app with a JDK 21+ — the capacitor-android module requires sourceCompatibility 21. In Android Studio: Settings → Build Tools → Gradle → Gradle JDK.

License

MIT