# Whiteboard sharing

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The Video SDK for iOS lets an app share a whiteboard within a session, allowing users to start, view, and collaborate on a digital canvas. Manage this feature through the dedicated `ZoomVideoSDKWhiteboardHelper`.

## Integrate the module

To add whiteboard support to your iOS app, you primarily use the `ZoomVideoSDKWhiteboardHelper` interface. Access it through `getWhiteboardHelper`.

```swift
ZoomVideoSDK.shareInstance()?.getWhiteboardHelper()
```

You can also manage events using the `ZoomVideoSDKDelegate` protocol.
Manage these dependencies using **CocoaPods** or **Swift Package Manager (SPM)**. You can also import them manually like how you have done it for the other xcframeworks with "Embed & Sign".

## Share and manage the whiteboard

These helper classes are available for you to manage the whiteboard.

| Method                      | Purpose                                                            |
| --------------------------- | ------------------------------------------------------------------ |
| `getWhiteboardHelper()`     | Retrieves the instance of the whiteboard helper.                   |
| `canStartShareWhiteboard()` | Checks if the current user is permitted to start a new whiteboard. |
| `startShareWhiteboard()`    | Starts a new, blank whiteboard session.                            |
| `canStopShareWhiteboard()`  | Checks if the current user can stop the active whiteboard share.   |
| `stopShareWhiteboard()`     | Stops the current whiteboard share.                                |

```swift
// 1. Get the Whiteboard Helper
if let whiteboardHelper = ZoomVideoSDK.shareInstance()?.getWhiteboardHelper() {
    // 2. Start Sharing
    if whiteboardHelper.canStartShareWhiteboard() {
        let result = whiteboardHelper.startShareWhiteboard()
        // Check 'result' for success (.success)
    }

    // 3. Stop Sharing
    if whiteboardHelper.canStopShareWhiteboard() {
        let result = whiteboardHelper.stopShareWhiteboard()
        // Check 'result' for success
    }
}
```

```objectivec
// 1. Get the Whiteboard Helper
ZoomVideoSDKWhiteboardHelper *whiteboardHelper = [[ZoomVideoSDK shareInstance] getWhiteboardHelper];

// 2. Start Sharing
if ([whiteboardHelper canStartShareWhiteboard]) {
    ZoomVideoSDKError result = [whiteboardHelper startShareWhiteboard];
    // Check 'result' for success (ZoomVideoSDKErrors_Success)
}

// 3. Stop Sharing
if ([whiteboardHelper canStopShareWhiteboard]) {
    ZoomVideoSDKError result = [whiteboardHelper stopShareWhiteboard];
    // Check 'result' for success
}
```

## View or subscribe to the whiteboard

To allow users to see and interact with a shared whiteboard, you must subscribe to the stream and provide a `UIView` for rendering.

| Method                                      | Purpose                                                                                           |
| ------------------------------------------- | ------------------------------------------------------------------------------------------------- |
| `subscribeWhiteboard:(UIViewController*)vc` | Subscribes to the active whiteboard stream and renders it within the specified `UIViewController` |
| `unSubscribeWhiteboard()`                   | Unsubscribes from the whiteboard stream and stops rendering.                                      |
| `isOtherSharingWhiteboard`                  | Checks if any other user is currently sharing a whiteboard.                                       |

### To view the whiteboard

```swift
// Get the helper as shown above
if let whiteboardHelper = ZoomVideoSDK.shareInstance()?.getWhiteboardHelper() {
    whiteboardHelper.subscribeWhiteboard(selectedVC)
    // The whiteboard UI will now be displayed in the selectedVC
}
```

```objectivec
// Get the helper as shown above
ZoomVideoSDKWhiteboardHelper *whiteboardHelper = [[ZoomVideoSDK shareInstance] getWhiteboardHelper];

[whiteboardHelper subscribeWhiteboard:selectedVC];
// The whiteboard UI will now be displayed in the selectedVC
```

### To stop viewing the whiteboard

```swift
// Get the helper as shown above
if let whiteboardHelper = ZoomVideoSDK.shareInstance()?.getWhiteboardHelper() {
    whiteboardHelper.unSubscribeWhiteboard()
}
```

```objectivec
// Get the helper as shown above
ZoomVideoSDKWhiteboardHelper *whiteboardHelper = [[ZoomVideoSDK shareInstance] getWhiteboardHelper];
[whiteboardHelper unSubscribeWhiteboard];
```

## Whiteboard events and status changes

You'll handle whiteboard events in your `ZoomVideoSDKDelegate` implementation.

| Callback/Method                                                                                                                    | Purpose                                                                                                  |
| ---------------------------------------------------------------------------------------------------------------------------------- | -------------------------------------------------------------------------------------------------------- |
| `onUserWhiteboardShareStatusChanged(_ user: ZoomVideoSDKUser, whiteboardhelper whiteboardHelper: ZoomVideoSDKWhiteboardHelper) {}` | Called when any user starts or stops sharing a whiteboard. This is your cue to subscribe or unsubscribe. |
| `ZoomVideoSDKUser.getWhiteboardStatus()`                                                                                           | Returns a user's current whiteboard status (.started or .stopped).                                       |

```swift
// Implement this method in your class that conforms to ZoomVideoSDKDelegate
func onUserWhiteboardShareStatusChanged(_ user: ZoomVideoSDKUser, whiteboardhelper whiteboardHelper: ZoomVideoSDKWhiteboardHelper) {
    switch user.getWhiteboardStatus() {
    case .started:
        // A user has started sharing a whiteboard. Subscribe to display it.
        whiteboardHelper.subscribeWhiteboard(selectedVC)
    case .stopped:
        // The whiteboard sharing has ended. Unsubscribe to remove the view.
        whiteboardHelper.unSubscribeWhiteboard()
    }
}
```

```objectivec
// Implement this method in your class that conforms to ZoomVideoSDKDelegate
-(void)onUserWhiteboardShareStatusChanged:(ZoomVideoSDKUser *_Nonnull)user whiteboardhelper:(ZoomVideoSDKWhiteboardHelper*_Nonnull)whiteboardHelper {
    if (user.getWhiteboardStatus == ZoomVideoSDKWhiteboardStatus_Started) {
        // A user has started sharing a whiteboard. Subscribe to display it.
        [whiteboardHelper subscribeWhiteboard:selectedVC];
    } else {
        // The whiteboard sharing has ended. Unsubscribe to remove the view.
        [whiteboardHelper unSubscribeWhiteboard];
    }
}
```

## Export whiteboard content

Export the whiteboard as a PDF document.

| Method/Enum                                                                                 | Purpose                                                                                                       |
| ------------------------------------------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------- |
| `exportWhiteboard:(ZoomVideoSDKWhiteboardExportFormatType)format`                           | Triggers the asynchronous export process. Currently supports .PDF.                                            |
| `ZoomVideoSDKWhiteboardExportFormatType`                                                    | The enum value to specify PDF as the export format.                                                           |
| `onWhiteboardExported:(ZoomVideoSDKWhiteboardExportFormatType)format data:(NSData*)data {}` | The delegate callback that provides the exported file data as an NSData (Objective-C) or Data (Swift) object. |

### To export and retrieve the data

```swift
// 1. Trigger the export
if let whiteboardHelper = ZoomVideoSDK.shareInstance()?.getWhiteboardHelper() {
    whiteboardHelper.exportWhiteboard(.format_PDF)
}

// 2. Receive the data in your delegate
func onWhiteboardExported(format: ZoomVideoSDKWhiteboardExportFormatType, data: Data) {
    if format == .format_PDF {
        // 'data' is the Swift Data object (byte array) of the PDF file.
        // You can now write this Data object to a file on the device.
        savePdfFile(data)
    }
}
```

```objectivec
// 1. Trigger the export
ZoomVideoSDKWhiteboardHelper *whiteboardHelper = [[ZoomVideoSDK shareInstance] getWhiteboardHelper];
[whiteboardHelper exportWhiteboard:ZoomVideoSDKWhiteboardExport_Format_PDF];

// 2. Receive the data in your delegate
- (void)onWhiteboardExported:(ZoomVideoSDKWhiteboardExportFormatType)format data:(NSData*)data {
    if (format == ZoomVideoSDKWhiteboardExport_Format_PDF) {
        // 'data' is the NSData object of the PDF file.
        // You can now write this NSData object to a file on the device.
        [self savePdfFile:data];
    }
}
```

## Manage the data

Because the whiteboard data isn't stored in the cloud, you'll need to handle the data storage. Data can be lost when someone stops sharing the whiteboard, a user leaves a session, or when a user joins a sub-session, or when the app crashes or has network connectivity issues.