nativescript-barcodescanner

NativeScript BarcodeScanner

Want a quick demo?

• git clone https://github.com/EddyVerbruggen/nativescript-barcodescanner barcodedemo
• cd barcodedemo
• npm run setup
• npm run demo.android (or demo.ios / demo.ios.device)

Supported barcode types

iOS and Android

• CODE_39
• CODE_93
• CODE_128
• EAN_8
• EAN_13
• QR_CODE
• UPC_E
• AZTEC (on Android only when passed in explicity via formats)
• PDF_417 (on Android only when passed in explicity via formats)

Android only

• DATA_MATRIX
• CODABAR
• MAXICODE
• ITF
• RSS_14
• UPC_A

Installation

Make sure you're using NativeScript 2.3.0 or higher. Run npm install -g nativescript if not.

From the command prompt go to your app's root folder and execute:

tns plugin add nativescript-barcodescanner

iOS runtime permission reason

You've probably seen a permission popup like this before (this plugin will trigger one as well, automatically):

iOS 10+ requires not only this popup, but also a reason. In this case it's "We'd like to use the Camera ..".

You can provide your own reason for accessing the camera by adding something like this to app/App_Resources/ios/Info.plist:

  <key>NSCameraUsageDescription</key>
  <string>My reason justifying fooling around with your camera</string>

To not crash your app in case you forgot to provide the reason this plugin adds an empty reason to the .plist during build. This value gets overridden by anything you specified yourself. You're welcome.

Usage

Tip: during a scan you can use the volume up/down buttons to toggle the torch.

function: scan (single mode)

TypeScript

  import {BarcodeScanner} from "nativescript-barcodescanner";
  let barcodescanner = new BarcodeScanner();

  barcodescanner.scan({
    formats: "QR_CODE, EAN_13",
    cancelLabel: "EXIT. Also, try the volume buttons!", // iOS only, default 'Close'
    message: "Use the volume buttons for extra light", // Android only, default is 'Place a barcode inside the viewfinder rectangle to scan it.'
    showFlipCameraButton: true,   // default false
    preferFrontCamera: false,     // default false
    showTorchButton: true,        // iOS only, default false
    orientation: orientation,     // Android only, default undefined (sensor-driven orientation), other options: portrait|landscape
    openSettingsIfPermissionWasPreviouslyDenied: true // On iOS you can send the user to the settings app if access was previously denied
  }).then((result) => {
      // Note that this Promise is never invoked when a 'continuousScanCallback' function is provided
      alert({
        title: "Scan result",
        message: "Format: " + result.format + ",\nValue: " + result.text,
        okButtonText: "OK"
      });
    }, (errorMessage) => {
      console.log("No scan. " + errorMessage);
    }
  );

JavaScript

  var BarcodeScanner = require("nativescript-barcodescanner").BarcodeScanner;
  var barcodescanner = new BarcodeScanner();

  barcodescanner.scan({
    formats: "QR_CODE,PDF_417",   // Pass in of you want to restrict scanning to certain types
    cancelLabel: "EXIT. Also, try the volume buttons!", // iOS only, default 'Close'
    message: "Use the volume buttons for extra light", // Android only, default is 'Place a barcode inside the viewfinder rectangle to scan it.'
    showFlipCameraButton: true,   // default false
    preferFrontCamera: false,     // default false
    showTorchButton: true,        // iOS only, default false
    orientation: "landscape",     // Android only, optionally lock the orientation to either "portrait" or "landscape"
    openSettingsIfPermissionWasPreviouslyDenied: true // On iOS you can send the user to the settings app if access was previously denied
  }).then(
      function(result) {
        console.log("Scan format: " + result.format);
        console.log("Scan text:   " + result.text);
      },
      function(error) {
        console.log("No scan: " + error);
      }
  );

function: scan (bulk / continuous mode)

In this mode the scanner will continuously report scanned codes back to your code, but it will only be dismissed if the user tells it to, or you call stop programmatically.

The plugin handles duplicates for you so don't worry about checking those; every result withing the same scan session is unique unless you set reportDuplicates to true.

Here's an example of scanning 3 unique QR codes and then stopping scanning programmatically. You'll notice that the Promise will no longer receive the result as there may be many results:

JavaScript

  var count = 0;
  barcodescanner.scan({
    formats: "QR_CODE",
    // this callback will be invoked for every unique scan in realtime!
    continuousScanCallback: function (result) {
      count++;
      console.log(result.format + ": " + result.text + " (count: " + count + ")");
      if (count == 3) {
        barcodescanner.stop();
      }
    },
    reportDuplicates: false // which is the default
  }).then(
      function() {
        console.log("We're now reporting scan results in 'continuousScanCallback'");
      },
      function(error) {
        console.log("No scan: " + error);
      }
  );

function: available

Note that the iOS implementation will always return true at the moment, on Android we actually check for a camera to be available.

JavaScript

  var barcodescanner = require("nativescript-barcodescanner");

  barcodescanner.available().then(
      function(avail) {
        console.log("Available? " + avail);
      }
  );

function: hasCameraPermission / requestCameraPermission

On Android 6+ you need to request permission to use the camera at runtime when targeting API level 23+. Even if the uses-permission tag for the Camera is present in AndroidManifest.xml.

On iOS 10+ there's something similar going on.

Since version 1.5.0 you can let the plugin handle this for you (if need be a prompt will be shown to the user when the scanner launches), but if for some reason you want to handle permissions yourself you can use these functions.

JavaScript

  barcodescanner.hasCameraPermission().then(
      function(granted) {
        // if this is 'false' you probably want to call 'requestCameraPermission' now
        console.log("Has Camera Permission? " + result);
      }
  );

  // if no permission was granted previously this wil open a user consent screen
  barcodescanner.requestCameraPermission().then(
      function() {
        console.log("Camera permission requested");
      }
  );

Usage with nativescript-angular

When using Angular 2, it is best to inject dependencies into your classes. Here is an example of how you can set up nativescript-barcodescanner in an Angular 2 app with dependency injection.

1. Register the provider with your module

   //app.module.ts
   import { NgModule, ValueProvider } from '@angular/core';
   import { BarcodeScanner } from 'nativescript-barcodescanner';
   //other imports
   
   @NgModule({
     //bootstrap, declarations, imports, etc.
     providers: [
       BarcodeScanner
     ]
   })
   export class AppModule {}
   

2. Inject it into your component

   //my-component.ts
   import { Component, Inject } from '@angular/core';
   import { BarcodeScanner } from 'nativescript-barcodescanner';
   //other imports
   
   @Component({ ... })
   export class MyComponent {
     constructor(private barcodeScanner: BarcodeScanner) {
     }
   
     //use the barcodescanner wherever you need it. See general usage above.
     scanBarcode() {
       this.barcodeScanner.scan({ ... });
     }
   }
   

Changelog

• 2.1.0 iOS now also honors the preferFrontCamera and showFlipCameraButton settings. Also, added showTorchButton (iOS only for now).
• 2.0.0 Conversion to TypeScript (note that the JS require syntax is now slightly different!).
• 1.5.0 Auto-permission handling. Use the volume up/down buttons to toggle the torch.
• 1.4.0 Bulk scanning.