BLEOperations

Block-based lib, which aims to ease working with BLE peripherals.

Rationale

To read or write a characteristic of a BLE device, you have to do several operations (given that you've alreade scanned and found the device):

• Connect to a particular peripheral, if it's not already connected
• Find a particular service by uuid
• Find a particular characteristic by uuid
• Read or write to found characteristic

On each stage of this process, several annoying things can happen:

• An operation can take too long (connection attempts never time out, for instance)
• Some CBError can arise
• A connection could be dropped by either side
• Bluetooth can be turned off/disallowed

All the callbacks are sent back via delegate pattern, so you have a bunch CBCentralManagerDelegate and CBPeripheralDelegate methods and have to decide inside of them, what is the operation, which is currently going on and act accordingly.

Main design idea

To execute an read/write characteristic operation, you should be able to call one block-based method. Inside that method, there is a series of BLE operations, all timeout and disconnect events are handled and are posted back via block.

Example

So, you want to read some characteristic, you've found the peripheral, now

// Assuming you already have a proper CBCentralManager instance, otherwise, how would you scan
//
BLEOperationsManager * opsManager = [BLEOperationsManager alloc] initWithCentral: self.centralManager];

[opsManager readValueOfCharacteristicWithUuid: [CBUUID UUIDWithString: kChUuid]
                              serviceWithUuid: [CBUUID UUIDWithString: kServiceUuid]
                                 onPeripheral: self.selectedPeripheral
                                   completion: ^(NSData * value, NSError * error) {
                                       if (error)
                                       {
                                           [self handleBleError: error];
                                       }
                                       else if (!value)
                                       {
                                           [self finishBleOperation];
                                       }
                                       else
                                       {
                                           // do whatever we please
                                       }                                       
                                   }];