Sending custom data via UIActivityViewController

Question

Im trying to send data (NSData) from my app on one iOS Device to another via AirDrop using the UIActivityViewController. I have created a new CSM (custom data type) in my ap

Answer 1

You should take a look at the AirDrop sample code that covers the case of defining your own file type and sharing that with your app on the other device. The key part if you want to share raw data is that you have to create an instance of UIActivityItemSource and pass that to UIActivityViewController. Something like this:

class DataActivityItemSource: NSObject, UIActivityItemSource {
    let myData: NSData
    let typeIdentifier: String
    let subject: String
    let previewImage: UIImage

    init(myData: NSData, typeIdentifier: String, subject: String, previewImage: UIImage) {
        self.myData = myData
        self.typeIdentifier = typeIdentifier
        self.subject = subject
        self.previewImage = previewImage
    }

    // called to determine data type. only the class of the return type is consulted. it should match what -itemForActivityType: returns later
    @objc func activityViewControllerPlaceholderItem(activityViewController: UIActivityViewController) -> AnyObject {
        return myData
    }

    // called to fetch data after an activity is selected. you can return nil.
    @objc func activityViewController(activityViewController: UIActivityViewController, itemForActivityType activityType: String) -> AnyObject? {
        return myData
    }

    // if activity supports a Subject field. iOS 7.0
    @objc func activityViewController(activityViewController: UIActivityViewController, subjectForActivityType activityType: String?) -> String {
        return subject
    }

    // UTI for item if it is an NSData. iOS 7.0. will be called with nil activity and then selected activity
    @objc func activityViewController(activityViewController: UIActivityViewController, dataTypeIdentifierForActivityType activityType: String?) -> String {
        return typeIdentifier
    }

    // if activity supports preview image. iOS 7.0
    @objc func activityViewController(activityViewController: UIActivityViewController, thumbnailImageForActivityType activityType: String?, suggestedSize size: CGSize) -> UIImage? {
        // look at suggestedSize and resize image (see AirDrop sample code for how to do this)
        return previewImage
    }
}


@IBAction func shareButton(sender: AnyObject) {

    // myData is the object I want to send to be used in my app on another device
    let itemSource = DataActivityItemSource(myData, "com.foo.ppm.typeIdentifier", "My Amazing Journey", aPreviewImage)
    let vc = UIActivityViewController(activityItems: [itemSource],applicationActivities: [])
    presentViewController(vc, animated: true, completion: nil)

}