Sample NURAPI applications for iOS

NurAPI Bluetooth framework

The framework provides an interface that works as a bridge between the NurAPI and the iOS Bluetooth stack. It is mainly responsible for providing a mechanism for NurAPI to communicate with the CoreBluetooth framework in iOS as well as relaying events from NurAPI to the application. It also provides a simpler API to scan for and connect to RFID devices.

The NurAPIBluetooth framework is accessible from both Objective-C and Swift.

Using the framework from Objective-C

Drag the framework into an application. Add the framework to Embedded binaries section in the General tab of your app target. Now you can import the <NurAPIBluetooth/Bluetooth.h> header:

#import <NurAPIBluetooth/Bluetooth.h>`

All functionality is accessed through a singleton method, for example:

[[Bluetooth sharedinstance] startScanning];

All results from the Bluetooth class are delivered to registered delegates. An application that uses the class should have some component implement the BluetoothDelegate and register it as a delegate, for example:

// a class that implements the BluetoothDelegate protocol
@interface SelectReaderViewController : UIViewController <BluetoothDelegate>
...
@end

@implementation SelectReaderViewController
...

- (void)viewDidLoad {
    [super viewDidLoad];

    // register as a delegate
    [[Bluetooth sharedInstance] registerDelegate:self];
    ...
}

@end

See the BluetoothDelegate for all the methods that can be implemented.

When a connection to a reader is formed all communication with the device is performed through the low level NurAPI functions. These require a handle which can be accessed from the nurapiHandleproperty like this:

// start an inventory stream
int error = NurApiStartInventoryStream( [Bluetooth sharedInstance].nurapiHandle, rounds, q, session );
if ( error != NUR_NO_ERROR ) {
    // failed to start stream
}

Please refer to that header for more detailed instructions on how to access the available functionality.

Thread model

All callbacks to the BluetoothDelegate are on different threads than the main application thread. This means that care needs to be taken when accessing application data and the UI. All low level NurAPI calls should also be performed on a secondary thread as some of the calls can block for a long time and deadlocks can occur if delegate methods are called. An example that fetches the NurAPI version string:

// a queue used to dispatch all NurAPI calls
@property (nonatomic, strong) dispatch_queue_t dispatchQueue;
...

// use the global queue with default priority
self.dispatchQueue = dispatch_get_global_queue( DISPATCH_QUEUE_PRIORITY_DEFAULT, 0 );
...

dispatch_async(self.dispatchQueue, ^{
   char buffer[256];
   if ( NurApiGetFileVersion( buffer, 256 ) ) {
       NSString * versionString = [NSString stringWithCString:buffer encoding:NSUTF8StringEncoding];

       // set the UILabel on the main thread
       dispatch_async(dispatch_get_main_queue(), ^{
           self.nurApiVersionLabel.text = [NSString stringWithFormat:@"NurAPI version: %@", versionString];
       } );
   }
   else {
       // failed to get version
       ...
   }
} );

Using the framework from Swift

Drag the framework into an application. Add the framework to Embedded binaries section in the General tab of your app target. In order to use the framework in Swift code the project needs a bridging header. The contents of the bridging header is simply:

#import <NurAPIBluetooth/Bluetooth.h>`

Now the framework can be imported in Swift with:

import NurAPIBluetooth

Once the bridging header is in place the framework can be used just as in the Objective-C

NURAPI Objective-C Demo

This is a demo application that shows how to use NURAPI in an Objective-C application. To build you need the NURAPIBluetooth framework. Drag and drop it from Finder into the Frameworks group and then add the framework to Embedded binaries section in the General tab of your application target.

The application builds both for the iOS simulator and real devices, but the simulator does not have Bluetooth support. The application will start in the simulator, but the Bluetooth subsystem will simply never be enabled.

NURAPI Swift Demo

This is a minimal demo that shows how to use the NURAPI framework from a Swift application. Add the framework to the project as per the Objective-C version. There is a bridging header that makes the framework available to the Swift code.

Functionality wise the Swift version contains the same storyboard, but only the initial view controller that starts the scanning and lists the found readers is implemented.

NURApiBluetooth framework

The NURAPIBluetooth framework contains shared libraries for both device and simulator architectures. This allows the same framework to be used for both simulator testing as well as deploying on devices. When an application is submitted to the App Store the i386 simulator libraries can not be included and must be stripped away from the build. This can be easily done with a build phase script that is executed last in the build.

The relevant script is below. It strips out all architectures that are not currently needed. If your Info.plist is in some other location adapt the path on line FRAMEWORK_EXECUTABLE_NAME=$(defaults read "$FRAMEWORK/Info.plist" CFBundleExecutable).

APP_PATH="${TARGET_BUILD_DIR}/${WRAPPER_NAME}"

# This script loops through the frameworks embedded in the application and
# removes unused architectures.
find "$APP_PATH" -name '*.framework' -type d | while read -r FRAMEWORK
do
    FRAMEWORK_EXECUTABLE_NAME=$(defaults read "$FRAMEWORK/Info.plist" CFBundleExecutable)
    FRAMEWORK_EXECUTABLE_PATH="$FRAMEWORK/$FRAMEWORK_EXECUTABLE_NAME"
    echo "Executable is $FRAMEWORK_EXECUTABLE_PATH"

    EXTRACTED_ARCHS=()

    for ARCH in $ARCHS
    do
        echo "Extracting $ARCH from $FRAMEWORK_EXECUTABLE_NAME"
        lipo -extract "$ARCH" "$FRAMEWORK_EXECUTABLE_PATH" -o "$FRAMEWORK_EXECUTABLE_PATH-$ARCH"
        EXTRACTED_ARCHS+=("$FRAMEWORK_EXECUTABLE_PATH-$ARCH")
    done

    echo "Merging extracted architectures: ${ARCHS}"
    lipo -o "$FRAMEWORK_EXECUTABLE_PATH-merged" -create "${EXTRACTED_ARCHS[@]}"
    rm "${EXTRACTED_ARCHS[@]}"

    echo "Replacing original executable with thinned version"
    rm "$FRAMEWORK_EXECUTABLE_PATH"
    mv "$FRAMEWORK_EXECUTABLE_PATH-merged" "$FRAMEWORK_EXECUTABLE_PATH"
done

For more discussion and the original script, see:

http://ikennd.ac/blog/2015/02/stripping-unwanted-architectures-from-dynamic-libraries-in-xcode/

License

All source files in this repository is provided under terms specified in LICENSE file.