Fix iOS17 bug where encoding buffer does not include newline character (

#280) * fix(bug): changes default encoding to fix bug in iOS17 where newline character is not stringified * Update docs (#280) --------- Co-authored-by: James Best <[email protected]>
kenjdavidson · Nov 21, 2023 · 47e3113 · 47e3113
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diff --git a/docs/src/docs/ios/index.mdx b/docs/src/docs/ios/index.mdx
@@ -17,7 +17,7 @@ Once installed [autolinking](https://github.com/react-native-community/cli/blob/
 
 Remember to make sure you have your protocol strings provided within your application `plist` file - this is a requirement of the External Accessory framework.  This is the top cause of:
 
-> `Unhandled JS Exception: TypeError: Cannot read property 'xxx' of undefined` 
+> `Unhandled JS Exception: TypeError: Cannot read property 'xxx' of undefined`
 
 while attempting to use the library.  An example of what this looks like in your own `plist` file is:
 
@@ -42,6 +42,9 @@ There are also a number of other IOS security related items that are required:
 
 ```
 
+
+> In iOS17 a seemingly silent change has occurred where `utf` encoded strings with newline characters are encoded in an unexpected way. This means that the default delimiter of a new line character does not get picked up in the `read` function and so no message is returned. To fix this the default encoding has been changed to  `nonLossyASCII`. [Encoding Docs](https://developer.apple.com/documentation/swift/string/encoding/nonlossyascii).
+
 ## F.A.Q
 
 #### Why isn't my protocol working?
@@ -52,7 +55,7 @@ Remember these are MFi protocols, they are not communication protocols.  This is
 
 You either need to find the protocols listed on the companies website (Zebra for example has some posted) but in most cases these are kept super secret; like Fight Club secret!
 
-Getting devices MFi compliant costs companies a boat load of money, so they don't generally give these out for free.  You'll need to work with a vendor constantly (as you'll find there are some super annoying things to do for releasing). 
+Getting devices MFi compliant costs companies a boat load of money, so they don't generally give these out for free.  You'll need to work with a vendor constantly (as you'll find there are some super annoying things to do for releasing).
 
 #### I Can See my Device in Bluetooth Screen
 

diff --git a/docs/src/home/index.mdx b/docs/src/home/index.mdx
@@ -5,23 +5,25 @@
 - [https://github.com/rusel1989/react-native-bluetooth-serial](https://github.com/rusel1989/react-native-bluetooth-serial)
 - [https://github.com/nuttawutmalee/react-native-bluetooth-serial-next](https://github.com/nuttawutmalee/react-native-bluetooth-serial-next)
 
-are both fantastic implementations but they fall back to BLE on IOS. 
+are both fantastic implementations but they fall back to BLE on IOS.
 
 ## Environments
 
 The following environments are supported with React Native and this library:
 
-## IOS 
+## IOS
 
-Devices using bluetooth classic and MFi requires communication through the [External Accessory](https://developer.apple.com/documentation/externalaccessory) framework.  Please note that while working with this library on IOS, you'll need to become accustomed with the Apple and their [MFi program](https://en.wikipedia.org/wiki/MFi_Program).  
+Devices using bluetooth classic and MFi requires communication through the [External Accessory](https://developer.apple.com/documentation/externalaccessory) framework.  Please note that while working with this library on IOS, you'll need to become accustomed with the Apple and their [MFi program](https://en.wikipedia.org/wiki/MFi_Program).
 
 Here are some links to check out:
 
 - [MFi_Program](https://en.wikipedia.org/wiki/MFi_Program)
 - [EA Demo Introduction](https://developer.apple.com/library/archive/samplecode/EADemo/Introduction/Intro.html)
 - [Streams](https://developer.apple.com/documentation/foundation/stream)
 
-## Android 
+> In iOS17 a seemingly silent change has occurred where `utf` encoded strings with newline characters are encoded in an unexpected way. This means that the default delimiter of a new line character does not get picked up in the `read` function and so no message is returned. To fix this the default encoding has been changed to  `nonLossyASCII`. [Encoding Docs](https://developer.apple.com/documentation/swift/string/encoding/nonlossyascii).
+
+## Android
 
 Android uses the standard BluetoothAdapter for communication:
 
@@ -53,8 +55,8 @@ The following tables contains the best version availability based on OS type and
 | 1.70.x  | 0.70.0       | 11 ()    | IOS 9 | main            |
 
 > With how crazy mobile development is, it may or may not be possible to use the library in lower or
-> higher versions that those noted.  I will always accept reasonable pull requests that bridge the gap 
-> between usable and required versions.   This library can also be modified directly in your project and 
+> higher versions that those noted.  I will always accept reasonable pull requests that bridge the gap
+> between usable and required versions.   This library can also be modified directly in your project and
 > stored within your own project repository if needed.
 
 ## Changes
@@ -69,7 +71,7 @@ Installation, like almost everything, is done through `npm`:
 $ npm install react-native-bluetooth-classic --save
 ```
 
-Once installed [autolinking](https://github.com/react-native-community/cli/blob/master/docs/autolinking.md) will take over within your application.  
+Once installed [autolinking](https://github.com/react-native-community/cli/blob/master/docs/autolinking.md) will take over within your application.
 
 > With the changes in v1.0.0 it's possible that Autolinking doesn't actually work (just be prepared for that).  The goal is to have it 100% working and customizable as per the React Native documentation, but until then just beware.
 

diff --git a/ios/conn/DelimitedStringDeviceConnectionImpl.swift b/ios/conn/DelimitedStringDeviceConnectionImpl.swift
@@ -23,7 +23,7 @@ import ExternalAccessory
  * @author kendavidson
  */
 class DelimitedStringDeviceConnectionImpl : NSObject, DeviceConnection, StreamDelegate {
- 
+
     private var _dataReceivedDelegate: DataReceivedDelegate?
     var dataReceivedDelegate: DataReceivedDelegate? {
         set(newDelegate) {
@@ -38,55 +38,55 @@ class DelimitedStringDeviceConnectionImpl : NSObject, DeviceConnection, StreamDe
             return self._dataReceivedDelegate
         }
     }
-    
+
     private var session: EASession?
     private var inBuffer: Data
     private var outBuffer: Data
-    
+
     private(set) var accessory: EAAccessory
     private(set) var properties: Dictionary<String,Any>
-    
+
     private var readSize: Int
     private var delimiter: String
     private var encoding: String.Encoding
-    
+
     init(
         accessory: EAAccessory,
         options: Dictionary<String,Any>
     ) {
         self.accessory = accessory;
         self.properties = Dictionary<String,Any>()
         self.properties.merge(options) { $1 }
-        
+
         self.inBuffer = Data()
         self.outBuffer = Data()
-        
+
         // For lack of knowing how to actually do this properly, Swift (I can't stand) doesn't like
         // the enumeration method from Java.  If someone can figure this one out, let me know.
         if let value = self.properties["READ_SIZE"] { self.readSize = value as! Int }
         if let value = self.properties["read_size"] { self.readSize = value as! Int }
         else { self.readSize = 1024 }
-        
+
         if let value = self.properties["DELIMITER"] { self.delimiter = value as! String }
         else if let value = self.properties["delimiter"] { self.delimiter = value as! String }
         else { self.delimiter = "\n" }
-        
+
         if let value = self.properties["DEVICE_CHARSET"] { self.encoding = String.Encoding.from(value as! CFStringEncoding) }
         else if let value = self.properties["device_charset"] { self.encoding = String.Encoding.from(value as! CFStringEncoding) }
         else if let value = self.properties["charset"] { self.encoding = String.Encoding.from(value as! CFStringEncoding) }
-        else { self.encoding = String.Encoding.from(CFStringBuiltInEncodings.ASCII.rawValue) }
+        else { self.encoding = String.Encoding.from(CFStringBuiltInEncodings.nonLossyASCII.rawValue) }
     }
-    
+
     /**
      * This implementation attempts to open an EASession for the provided protocol string
      */
     func connect() throws {
         let protocolString: String = self.properties["PROTOCOL_STRING"] as! String
-        
+
         NSLog("(BluetoothDevice:connect) Attempting Bluetooth connection to %@ using protocol %@", accessory.serialNumber, protocolString)
         if let connected = EASession(accessory: accessory, forProtocol: protocolString) {
             self.session = connected
-            
+
             if let inStream = connected.inputStream,
                 let outStream = connected.outputStream {
                 inStream.delegate = self
@@ -97,10 +97,10 @@ class DelimitedStringDeviceConnectionImpl : NSObject, DeviceConnection, StreamDe
                 outStream.open()
             }
         } else {
-            throw BluetoothError.CONNECTION_FAILED            
+            throw BluetoothError.CONNECTION_FAILED
         }
     }
-    
+
     /**
      * Attempts to disconnect from the EAAccessory and EASession
      */
@@ -116,10 +116,10 @@ class DelimitedStringDeviceConnectionImpl : NSObject, DeviceConnection, StreamDe
                 outStream.remove(from: .main, forMode: .commonModes)
             }
         }
-        
+
         session = nil
     }
-    
+
     /**
      * Returns the number of mesages available.  As this is a delmited string connection, the number of messages
      * are the number of delimiters found.
@@ -129,7 +129,7 @@ class DelimitedStringDeviceConnectionImpl : NSObject, DeviceConnection, StreamDe
     func available() -> Int {
         var count = 0;
         let content = String(data: inBuffer, encoding: self.encoding)!
-        
+
         // I really hate swift, apparently String.isEmpty is ambiguious??
         if (delimiter.count == 0) {
             count = content.count
@@ -138,10 +138,10 @@ class DelimitedStringDeviceConnectionImpl : NSObject, DeviceConnection, StreamDe
                 count += 1
             }
         }
-        
+
         return count;
     }
-    
+
     /**
      * Attempts to write to the out buffer.  This intermedate step is required so that the StreamDelegate will find and read
      * the available information when more space is available on the stream.
@@ -151,7 +151,7 @@ class DelimitedStringDeviceConnectionImpl : NSObject, DeviceConnection, StreamDe
         if let sending = String(data: data, encoding: self.encoding) {
             NSLog("(BluetoothDevice:writeToDevice) Writing %@ to device %@", sending, accessory.serialNumber)
             outBuffer.append(data)
-            
+
             // If there is space available for writing then we want to kick off the process.
             // If all the data cannot be fully written, then the hasSpaceAvailable will be
             // fired and we can continue.  In most cases, we shouldn't be sending that much
@@ -160,10 +160,10 @@ class DelimitedStringDeviceConnectionImpl : NSObject, DeviceConnection, StreamDe
         } else {
             return false
         }
-        
+
         return true
     }
-    
+
     /**
      * Reads the next message from the inBuffer.  This particular implementation converse the inBuffer into a
      * String using the provided encoding, then search for the first instance of that delimiter, and finally
@@ -172,7 +172,7 @@ class DelimitedStringDeviceConnectionImpl : NSObject, DeviceConnection, StreamDe
     func read() -> String? {
         NSLog("(BluetoothDevice:readFromDevice) Reading device %@ until delimiter %@",
               self.accessory.serialNumber, self.delimiter)
-        
+
         let content = String(data: inBuffer, encoding: self.encoding)!
         var message:String?
 
@@ -186,18 +186,18 @@ class DelimitedStringDeviceConnectionImpl : NSObject, DeviceConnection, StreamDe
                     .data(using: self.encoding) ?? Data()
             }
         }
-        
+
         return message
     }
-    
+
     /**
-     * Removed all data from the in/out buffers. 
+     * Removed all data from the in/out buffers.
      */
     func clear() {
         inBuffer.removeAll()
         outBuffer.removeAll()
     }
-    
+
     /**
      * Implements the StreamDelegate stream method.
      */
@@ -232,7 +232,7 @@ class DelimitedStringDeviceConnectionImpl : NSObject, DeviceConnection, StreamDe
             NSLog("Stream %@ had some other event occur", aStream)
         }
     }
-    
+
     /**
      * Reads data from the session.inputStream when there are available bytes.  Data is
      * appended to the receivedData string for access later.  If there is a
@@ -241,24 +241,24 @@ class DelimitedStringDeviceConnectionImpl : NSObject, DeviceConnection, StreamDe
      */
     private func readDataFromStream(_ stream: InputStream) {
         let buffer = UnsafeMutablePointer<UInt8>.allocate(capacity: readSize)
-        
+
         while (stream.hasBytesAvailable) {
             let numBytesRead = stream.read(buffer, maxLength: readSize)
-            
+
             if (numBytesRead < 0) {
                 break;
             }
-            
+
             inBuffer.append(buffer, count: numBytesRead)
         }
-    
+
         if let delegate = self.dataReceivedDelegate {
             while let data = read() {
                 delegate.onReceivedData(fromDevice:  accessory, receivedData: data)
             }
         }
     }
-    
+
     /**
      * Attempts to write as much data to the OutputStream as possible - currently this is maxed out at 512
      * bytes per attempt.  If all the data can't be written at one time, then the remaining will be written
@@ -272,14 +272,14 @@ class DelimitedStringDeviceConnectionImpl : NSObject, DeviceConnection, StreamDe
             NSLog("(BluetoothDevice:writeData) No buffer data scheduled for deliver")
             return
         }
-        
+
         let len:Int = (outBuffer.count > self.readSize) ? self.readSize : outBuffer.count
         NSLog("(BluetoothDevice:writeData) Attempting to send %d bytes to the device", len)
-        
+
         let buffer:UnsafeMutablePointer<UInt8> = UnsafeMutablePointer.allocate(capacity: len)
         outBuffer.copyBytes(to: buffer, count: len)
         outBuffer.removeFirst(len)
-        
+
         let bytesWritten = stream.write(buffer, maxLength: len)
         NSLog("(BluetoothDevice:writeData) Sent %d bytes to the device", bytesWritten)
     }