🚨 Important 🚨
Forked from Capacitor community barcode scanner to add raw base64 segments in the response.
The package is published as @openit/capacitor-community-barcode-scanner
Original README below the line
Barcode Scanner
@capacitor-community/barcode-scanner
A fast and efficient (QR) barcode scanner for Capacitor.
Table of Contents
Maintainers
Maintainer | GitHub | Social |
---|
tafelnl | tafelnl | |
About
Supported barcodes
On iOS this library makes use of Apple's own AVFoundation
. This means this list of barcodes should be supported.
On Android this library uses zxing-android-embedded
which uses zxing
under the hood. That means this list of barcodes is supported.
Installation
npm install @capacitor-community/barcode-scanner
npx cap sync
iOS
On iOS, no further steps are needed.
Android
On Android, register the plugin in your main activity:
import com.dutchconcepts.capacitor.barcodescanner.BarcodeScanner;
public class MainActivity extends BridgeActivity {
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
this.init(
savedInstanceState,
new ArrayList<Class<? extends Plugin>>() {
{
add(BarcodeScanner.class);
}
}
);
}
}
Configuration
iOS
For iOS you need to set a usage description in your info.plist file.
This can be done by either adding it to the Source Code directly or by using Xcode Property List inspector.
Adding it to the source code directly
- Open up the Info.plist (in Xcode right-click > Open As > Source Code)
- With
<dict></dict>
change the following
<dict>
+ <key>NSCameraUsageDescription</key>
+ <string>To be able to scan barcodes</string>
</dict>
NOTE: "To be able to scan barcodes" can be substituted for anything you like.
Adding it by using Xcode Property List inspector
- Open up the Info.plist in Xcode (right-click > Open As > Property List)
- Next to "Information Property List" click on the tiny
+
button. - Under
key
, type "Privacy - Camera Usage Description" - Under
value
, type "To be able to scan barcodes"
NOTE: "To be able to scan barcodes" can be substituted for anything you like.
More info here: https://developer.apple.com/documentation/bundleresources/information_property_list/nscamerausagedescription
Android
Within your AndroidManifest.xml
file, change the following:
<?xml version="1.0" encoding="utf-8"?>
<manifest
xmlns:android="http://schemas.android.com/apk/res/android"
+ xmlns:tools="http://schemas.android.com/tools"
package="com.example">
<application
+ android:hardwareAccelerated="true"
>
</application>
+ <uses-permission android:name="android.permission.CAMERA" />
+ <uses-sdk tools:overrideLibrary="com.google.zxing.client.android" />
</manifest>
Usage
Scanning a (QR) barcode can be as simple as:
import { Plugins } from '@capacitor/core';
const startScan = async () => {
const { BarcodeScanner } = Plugins;
BarcodeScanner.hideBackground();
const result = await BarcodeScanner.startScan();
if (result.hasContent) {
console.log(result.content);
}
};
Opacity of the WebView
Because of the fact that the Scanner View will be rendered behind the WebView, you will have to call hideBackground()
to make the WebView and the <html>
element transparent. Every other element that needs transparency, you will have to handle yourself.
The <html>
element is made transparent by adding background: 'transparent';
to the style=""
attribute. So in theory it is possible that this is overwritten by some CSS property in your setup. Because this plugins does not aim to fix every single scenario out there, you will have to think of a workaround for this yourself, if this applies to you (probably not).
Stopping a scan
After startScan()
is resolved, the Scanner View will be automatically destroyed to save battery. But if you want to cancel the scan before startScan()
is resolved (AKA no code has been recognized yet), you will have to call stopScan()
manually. Example:
import { Plugins } from '@capacitor/core';
const stopScan = () => {
const { BarcodeScanner } = Plugins;
BarcodeScanner.showBackground();
BarcodeScanner.stopScan();
};
It is also important to think about cases where a users hits some sort of a back button (either hardware or software). It is advised to call stopScan()
in these types of situations as well.
In Vue.js you could do something like this in a specific view where you use the scanner:
<script>
import { Plugins } from '@capacitor/core';
export default {
methods: {
stopScan() {
const { BarcodeScanner } = Plugins;
BarcodeScanner.showBackground();
BarcodeScanner.stopScan();
},
},
deactivated() {
this.stopScan();
},
beforeDestroy() {
this.stopScan();
},
};
</script>
Preparing a scan
To boost performance and responsiveness (by just a bit), a prepare()
method is available. If you know your script will call startScan()
sometime very soon, you can call prepare()
to make startScan()
work even faster.
For example:
import { Plugins } from '@capacitor/core';
const prepare = () => {
const { BarcodeScanner } = Plugins;
BarcodeScanner.prepare();
};
const startScan = async () => {
const { BarcodeScanner } = Plugins;
BarcodeScanner.hideBackground();
const result = await BarcodeScanner.startScan();
if (result.hasContent) {
console.log(result.content);
}
};
const stopScan = () => {
const { BarcodeScanner } = Plugins;
BarcodeScanner.showBackground();
BarcodeScanner.stopScan();
};
const askUser = () => {
prepare();
const c = confirm('Do you want to scan a barcode?');
if (c) {
startScan();
} else {
stopScan();
}
};
askUser();
This is fully optional and would work the same as:
const startScan = async () => {
const { BarcodeScanner } = Plugins;
BarcodeScanner.hideBackground();
const result = await BarcodeScanner.startScan();
if (result.hasContent) {
console.log(result.content);
}
};
const askUser = () => {
const c = confirm('Do you want to scan a barcode?');
if (c) {
startScan();
}
};
askUser();
The latter will just appear a little slower to the user.
Permissions
This plugin does not automatically handle permissions. But the plugin does have a utility method to check and request the permission. You will have to request the permission from JavaScript. A simple example follows:
const checkPermission = async () => {
const { BarcodeScanner } = Plugins;
const status = await BarcodeScanner.checkPermission({ force: true });
if (status.granted) {
return true;
}
return false;
};
A more detailed and more UX-optimized example:
const didUserGrantPermission = async () => {
const { BarcodeScanner } = Plugins;
const status = await BarcodeScanner.checkPermission({ force: false });
if (status.granted) {
return true;
}
if (status.denied) {
return false;
}
if (status.asked) {
}
if (status.neverAsked) {
const c = confirm(
'We need your permission to use your camera to be able to scan barcodes',
);
if (!c) {
return false;
}
}
if (status.restricted || status.unknown) {
return false;
}
const statusRequest = await BarcodeScanner.checkPermission({ force: true });
if (statusRequest.asked) {
}
if (statusRequest.granted) {
return true;
}
return false;
};
didUserGrantPermission();
If a user denied the permission for good, status.denied
will be set to true. On Android this will happen only when the user checks the box never ask again
. To get the permission anyway you will have to redirect the user to the settings of the app. This can be done simply be doing the following:
const checkPermission = async () => {
const { BarcodeScanner } = Plugins;
const status = await BarcodeScanner.checkPermission();
if (status.denied) {
const c = confirm(
'If you want to grant permission for using your camera, enable it in the app settings.',
);
if (c) {
BarcodeScanner.openAppSettings();
}
}
};
Target only specific barcodes
You can setup the scanner to only recognize specific types of barcodes like this:
BarcodeScanner.startScan({ targetedFormats: ['QR_CODE'] })
If targetedFormats
is not specified or left empty, all types of barcodes will be targeted.
The following types are supported:
Category | Type | Android | iOS |
---|
1D Product |
UPC_A | ✔ | ✔** |
UPC_E | ✔ | ✔ |
UPC_EAN_EXTENSION | ✔ | ✖ |
EAN_8 | ✔ | ✔ |
EAN_13 | ✔ | ✔ |
1D Industrial |
CODE_39 | ✔ | ✔ |
CODE_39_MOD_43 | ✖ | ✔ |
CODE_93 | ✔ | ✔ |
CODE_128 | ✔ | ✔ |
CODABAR | ✔ | ✖ |
ITF | ✔ | ✔ |
ITF_14 | ✖ | ✔ |
2D |
AZTEC | ✔ | ✔ |
DATA_MATRIX | ✔ | ✔ |
MAXICODE | ✔ | ✖ |
PDF_417 | ✔ | ✔ |
QR_CODE | ✔ | ✔ |
RSS_14 | ✔ | ✖ |
RSS_EXPANDED | ✔ | ✖ |
** UPC_A
is supported on iOS, but according to the offical Apple docs it is part of EAN_13
. So you should specify EAN_13
to be able to scan this. If you want to distinguish them from one another, you should manually do so after getting the result.
Troubleshooting
I have a Error: Plugin BarcodeScanner does not respond to method call
error message on iOS
In Xcode click on Product
> Clean Build Folder
and try to build again.
I have a Cannot resolve symbol BarcodeScanner
error message in Android Studio
In Android Studio click File
> Sync Project with Gradle Files
and try to build again.
TODO
A non-exhaustive list of todos:
- Support for switching between cameras
- Support for toggling the flashlight
- Support for web