# Scanner API

The Scanner API enables an extension to access scanner data and available scanning sources supported by the device.

## ScannerApi

### ScannerApiContent

### scannerDataSubscribable

value: `RemoteSubscribable<ScannerSubscriptionResult>`

Creates a subscription to scan events
Provides an initial value and a callback to subscribe to value changes. Currently supports only one subscription.
You can utilize `makeStatefulSubscribable` on a `RemoteSubscribable` to implement multiple subscriptions.
Using `makeStatefulSubscribable` or the corresponding hooks counts as a subscription.

### scannerSourcesSubscribable

value: `RemoteSubscribable<ScannerSource[]>`

Creates a subscription to the scanning sources available on the POS device.
Provides an initial value and a callback to subscribe to value changes. Currently supports only one subscription.
You can utilize `makeStatefulSubscribable` on a `RemoteSubscribable` to implement multiple subscriptions.
Using `makeStatefulSubscribable` or the corresponding hooks counts as a subscription.

### ScannerSubscriptionResult

### data

value: `string`

The string data from the last scanner event received.

### source

value: `ScannerSource`

The scanning source from which the scan event came.

## Examples

The Scanner API enables an extension to access scanner data and available scanning sources supported by the device.



```tsx
import React from 'react';
import {
  Navigator,
  Screen,
  Stack,
  Text,
  useScannerDataSubscription,
  reactExtension,
} from '@shopify/ui-extensions-react/point-of-sale';

const SmartGridModal = () => {
  const {data, source} = useScannerDataSubscription();

  return (
    <Navigator>
      <Screen name="Home" title="Home">
        <Stack direction="horizontal">
          <Text>{`Scanned data: ${data || ''} with ${source || ''}`}</Text>
        </Stack>
      </Screen>
    </Navigator>
  );
};

export default reactExtension('pos.home.modal.render', () => (
  <SmartGridModal />
));

```

```ts
import {
  Navigator,
  Screen,
  Stack,
  Text,
  extension,
} from '@shopify/ui-extensions/point-of-sale';

export default extension('pos.home.modal.render', (root, api) => {
  const dataText = root.createComponent('Text', null, 'Scanned data: ');

  const sourceText = root.createComponent(
    'Text',
    null,
    'Scanned data source: ',
  );

  const stack1 = root.createComponent(Stack, {
    direction: 'horizontal',
  });

  const screen = root.createComponent(Screen, {
    title: 'Home',
    name: 'Home',
  });

  const navigator = root.createComponent(Navigator);

  stack1.append(dataText);
  stack1.append(sourceText);
  screen.append(stack1);
  navigator.append(screen);
  root.append(navigator);

  api.scanner.scannerDataSubscribable.subscribe((data, source) => {
    dataText.replaceChildren(`Scanned data: ${data || ''}`);
    sourceText.updateProps(`Scanned data source: ${source || ''}`);
  });
});

```



```tsx
import React from 'react';
import {
  Navigator,
  Screen,
  Stack,
  Text,
  useScannerSourcesSubscription,
  reactExtension,
} from '@shopify/ui-extensions-react/point-of-sale';

const SmartGridModal = () => {
  const scannerSources = useScannerSourcesSubscription();

  return (
    <Navigator>
      <Screen name="Home" title="Home">
        <Stack direction="horizontal">
          <Text>{`Available scanner sources: ${scannerSources}`}</Text>
        </Stack>
      </Screen>
    </Navigator>
  );
};

export default reactExtension('pos.home.modal.render', () => (
  <SmartGridModal />
));

```

```ts
import {
  Navigator,
  Screen,
  Stack,
  Text,
  extension,
} from '@shopify/ui-extensions/point-of-sale';

export default extension('pos.home.modal.render', (root, api) => {
  const scannerSourcesText = root.createComponent(
    'Text',
    null,
    'Available scanner sources: ',
  );

  const stack1 = root.createComponent(Stack, {
    direction: 'horizontal',
  });

  const screen = root.createComponent(Screen, {
    title: 'Home',
    name: 'Home',
  });

  const navigator = root.createComponent(Navigator);

  stack1.append(scannerSourcesText);
  screen.append(stack1);
  navigator.append(screen);
  root.append(navigator);

  api.scanner.scannerSourcesSubscribable.subscribe((sources) => {
    scannerSourcesText.replaceChildren(`Available scanner sources: ${sources}`);
  });
});

```


### Use cases

```tsx
import React from 'react';
import {
  Navigator,
  Screen,
  Stack,
  Text,
  useScannerDataSubscription,
  useApi,
  reactExtension,
} from '@shopify/ui-extensions-react/point-of-sale';

const SmartGridModal = () => {
  const api = useApi<'pos.home.modal.render'>();
  const {data} = useScannerDataSubscription();

  return (
    <Navigator>
      <Screen name="Home" title="Home">
        <Stack direction="horizontal">
          <Text>{`Scanned data: ${data || ''}`}</Text>
        </Stack>
      </Screen>
    </Navigator>
  );
};

export default reactExtension('pos.home.modal.render', () => (
  <SmartGridModal />
));

```

```ts
import React from 'react';
import {
  Navigator,
  Screen,
  Stack,
  Text,
  extension,
} from '@shopify/ui-extensions/point-of-sale';

export default extension('pos.home.modal.render', (root, api) => {
  const text = root.createComponent('Text', null, 'Scanned data: ');

  const stack = root.createComponent(Stack, {
    direction: 'horizontal',
  });

  const screen = root.createComponent(Screen, {
    title: 'Home',
    name: 'Home',
  });

  const navigator = root.createComponent(Navigator);

  stack.append(text);
  screen.append(stack);
  navigator.append(screen);
  root.append(navigator);

  api.scanner.scannerDataSubscribable.subscribe((data) => {
    text.replaceChildren(`Scanned data: ${data || ''}`);
  });
});

```

```tsx
import React from 'react';
import {
  CameraScanner,
  Navigator,
  Screen,
  Stack,
  Text,
  useScannerDataSubscription,
  useScannerSourcesSubscription,
  reactExtension,
} from '@shopify/ui-extensions-react/point-of-sale';

const SmartGridModal = () => {
  const {data, source} = useScannerDataSubscription();
  const availableScanners = useScannerSourcesSubscription();
  const hasCameraScanner = availableScanners.includes('camera');

  return (
    <Navigator>
      <Screen name="Home" title="Home">
        <Stack direction="horizontal">
          {hasCameraScanner ? (
            <CameraScanner />
          ) : (
            <Stack direction="vertical" alignment="space-evenly">
              <Text>{`Scanned data: ${data || ''}`}</Text>
              <Text>{`Scanned data source: ${source || ''}`}</Text>
            </Stack>
          )}
        </Stack>
      </Screen>
    </Navigator>
  );
};

export default reactExtension('pos.home.modal.render', () => (
  <SmartGridModal />
));

```

```ts
import {
  CameraScanner,
  Navigator,
  Screen,
  Stack,
  Text,
  extension,
} from '@shopify/ui-extensions/point-of-sale';

export default extension('pos.home.modal.render', (root, api) => {
  const dataText = root.createComponent('Text', null, 'Scanned data: ');

  const sourceText = root.createComponent(
    'Text',
    null,
    'Scanned data source: ',
  );

  const cameraScanner = root.createComponent(CameraScanner);
  const stack1 = root.createComponent(Stack, {
    direction: 'horizontal',
  });
  const stack2 = root.createComponent(Stack, {
    direction: 'vertical',
    alignment: 'space-evenly',
  });

  const screen = root.createComponent(Screen, {
    title: 'Home',
    name: 'Home',
  });

  const navigator = root.createComponent(Navigator);

  screen.append(stack1);
  navigator.append(screen);
  root.append(navigator);

  api.scanner.scannerDataSubscribable.subscribe((data, source) => {
    dataText.replaceChildren(`Scanned data: ${data || ''}`);
    sourceText.replaceChildren(`Scanned data source: ${source || ''}`);
  });

  api.scanner.scannerSourcesSubscribable.subscribe((sources) => {
    // Clear previous children to avoid duplicate appending
    stack1.children = [];
    stack2.children = [];

    if (sources.include('camera')) {
      stack1.append(cameraScanner);
    } else {
      stack2.append(dataText);
      stack2.append(sourceText);
      stack1.append(stack2);
    }
  });
});

```