Swift 4.1 Support (#32)

* Optimize a few things.
Create a public message structure to simplify and extend delegate.
Add background queue connect convenience method.
Have one delegate callback on disconnect.
Push errors out to delegate.
Rename SessionStream file.

* Fix compiler errors in test and sample app. Add comments for OCI changes.

* Make delegates weak references to avoid circular ownership
Add BatchReceiver sketch

* move MQTTMessage into models
make optional completion blocks truly optional

* Create MQTTBroker protocol

* create simple MQTTBatchingSession (pass-thru right now)

* MQTTConnectParams work in a framework

* fix bug when sending data in a disconnected state

* simplify life-cycle on connection errors

* Fix stream ready flow

* move all mqttparsing into session

* move packet parsing out of session

* Correct queue usage

* forgot the else

* Retry logic complete (for now)

* don’t reuse time intervals

* Add DatedSnapShot

* message id change

* DataSnapshot sendAll

* fix dated snapshot

* fix dated snapshot again

* Allow data snapshot to convert messages

* Fix read loop

* Swift 4 compatible with 3 changes.

* Add CustomStringConvertable to message, prototype file payload enum, make more structs

* cleanup lifecycle

* Break up networkPacket method

* move stream packet logic into Streamable

* bug fix

* Update README.md

* better session handling

* Update .travis.yml

* Add swift_version in podspec

* Bump podspec versions

* Fix typo

* Keep payload as Data to minimize changes to public interface

* Remove inline change comments

* Make keep alive timer optional

* Update deprecated string count

* Update deprecated timer method

* Update readme

* Cleanup whitespace

* Update Example project

* Fix typo

* Update tests to ensure connection is made in setUp before running tests

* Remove extraneous } from example project

* Ensure callbacks are handled on the main thread

* Remove new reconnecting session feature for now

* Cleanup error handling

* Add ping/heartbeat callback

* Make error Equatable

* Cleanup private/fileprivate

* General formatting cleanup

* Update tests and add end-to-end subscribe, publish, receive test

* Remove new reconnecting session feature for now

* Add description for errors

* Remove Broker class

* Don't dispatch to main thread as already on main by default

* Expose desired dispatch queue for delegate callbacks, default to main

* Fix bug with reading ping packets

* Call completion blocks on delegate thread

* Clear the delegate when deinit'd

* Include framework as project dependency

* Update closure error handling

* Use description instead of localizedDescription

* Update readme

* Add Swift Package Manager support

.travis.yml

@@ -1,8 +1,8 @@
 language: objective-c 
-osx_image: xcode8
+osx_image: xcode9.2
 before_install:
 - brew update
 - brew install mosquitto
 script:
 - /usr/local/opt/mosquitto/sbin/mosquitto -d
-- xcodebuild -project SwiftMQTT/SwiftMQTT.xcodeproj -scheme SwiftMQTT -sdk iphonesimulator -destination "name=iPhone 6s" test
+- xcodebuild -project SwiftMQTT/SwiftMQTT.xcodeproj -scheme SwiftMQTT -sdk iphonesimulator -destination "name=iPhone 8 Plus" test

Package.swift

@@ -0,0 +1,24 @@
+// swift-tools-version:4.0
+
+import PackageDescription
+
+let package = Package(
+    name: "SwiftMQTT",
+    products: [
+        .library(name: "SwiftMQTT", targets: ["SwiftMQTT"]),
+        ],
+    dependencies: [],
+    targets: [
+        .target(
+            name: "SwiftMQTT",
+            dependencies: [],
+            path: "SwiftMQTT/SwiftMQTT/"
+        ),
+        .testTarget(
+            name: "SwiftMQTTTests", 
+            dependencies: ["SwiftMQTT"],
+            path: "SwiftMQTT/SwiftMQTTTests/"
+        ),
+    ]
+)
+

README.md

@@ -1,72 +1,98 @@
 # SwiftMQTT
 
-MQTT Client in pure Swift ❤️️
+MQTT Client
 
 [![Build Status](https://travis-ci.org/aciidb0mb3r/SwiftMQTT.svg)](https://travis-ci.org/aciidb0mb3r/SwiftMQTT)
 [![Version](https://img.shields.io/cocoapods/v/SwiftMQTT.svg?style=flat)](http://cocoapods.org/pods/SwiftMQTT)
 [![License](https://img.shields.io/cocoapods/l/SwiftMQTT.svg?style=flat)](http://cocoapods.org/pods/SwiftMQTT)
 
-## Info
-* Fully written in Swift from ground up
-* Closures everywhere 😃
-* Includes test cases and sample project
-* Based on MQTT Version 3.1.1 (http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html#_Toc398718043)
+* Fully written in Swift 4
+* Robust error handling
+* Performant
+* Based on [MQTT 3.1.1 Specification](http://docs.oasis-open.org/mqtt/mqtt/v3.1.1/os/mqtt-v3.1.1-os.html)
 
-![Sample Project Screenshot](http://i.imgur.com/9lefVmVl.png)
-
-## How to use
+## Usage
 
 ### Create Session
 ```swift
-mqttSession = MQTTSession(host: "localhost", port: 1883, clientID: "swift", cleanSession: true, keepAlive: 15, useSSL: false)
+mqttSession = MQTTSession(
+	host: "localhost",
+	port: 1883,
+	clientID: "swift", // must be unique to the client
+	cleanSession: true,
+	keepAlive: 15,
+	useSSL: false
+)
 ```
 
 ### Connect
 ```swift
-mqttSession.connect { (succeeded, error) -> Void in
-  if succeeded {
-    print("Connected!")
-  }
+mqttSession.connect { error in
+    if error == .none {
+        print("Connected!")
+    } else {
+        print(error.description)
+    }
 }
 ```
 
 ### Subscribe
 ```swift
-mqttSession.subscribe(to: "/hey/cool", delivering: .atLeastOnce) { (succeeded, error) -> Void in
- if succeeded {
-    print("Subscribed!")
-  }
+let topic = "mytopic" 
+mqttSession.subscribe(to: topic, delivering: .atLeastOnce) { error in
+    if error == .none {
+        print("Subscribed to \(topic)!")
+    } else {
+        print(error.description)
+    }
 }
 ```
 
 ### Unsubscribe
 ```swift
- mqttSession.unSubscribe(from: ["/ok/cool", "/no/ok"]) { (succeeded, error) -> Void in
-  if succeeded {
-    print("unSubscribed!")
-  }
+let topic = "mytopic"
+mqttSession.unSubscribe(from: topic) { error in
+    if error == .none {
+        print("Unsubscribed from \(topic)!")
+    } else {
+        print(error.description)
+    }
 }
 ```
 
 ### Publish
-```swift
-let jsonDict = ["hey" : "sup"]
-let data = try! JSONSerialization.data(withJSONObject: jsonDict, options: .prettyPrinted)
 
-mqttSession.publish(data, in: "/hey/wassap", delivering: .atLeastOnce, retain: false) { (succeeded, error) -> Void in
-  if succeeded {
-    print("Published!")
-  }
+```swift
+let json = ["key" : "value"]
+let data = try! JSONSerialization.data(withJSONObject: json, options: .prettyPrinted)
+let topic = "mytopic"
+
+mqttSession.publish(data, in: topic, delivering: .atLeastOnce, retain: false) { error in
+    if error == .none {
+        print("Published data in \(topic)!")
+    } else {
+        print(error.description)
+    }
 }
-
 ```
+
 ### Conform to `MQTTSessionDelegate` to receive messages 
 ```swift
 mqttSession.delegate = self
 ```
 ```swift
-func mqttSession(session: MQTTSession, received message: Data, in topic: String) {
-	let string = String(data: message, encoding: .utf8)!
+func mqttDidReceive(message: MQTTMessage, from session: MQTTSession) {
+    print(message.topic)
+    print(message.stringRepresentation)
+}
+```
+```swift
+func mqttDidDisconnect(session: MQTTSession, error: MQTTSessionError) {
+    if error == .none {
+        print("Successfully disconnected from MQTT broker")
+    } else {
+        print(error.description)
+    }
 }
 ```
 
@@ -77,9 +103,24 @@ func mqttSession(session: MQTTSession, received message: Data, in topic: String)
 Install using [CocoaPods](http://cocoapods.org) by adding the following lines to your Podfile:
 
 ````ruby
-use_frameworks!
-pod 'SwiftMQTT'  
+target 'MyApp' do
+    use_frameworks!
+    pod 'SwiftMQTT'
+end
 ````
 
+### Carthage
+
+```
+github "aciidb0mb3r/SwiftMQTT"
+```
+
+### Swift Package Manager
+
+```swift
+dependencies: [
+    .package(url: "https://github.com/aciidb0mb3r/SwiftMQTT.git", from: "3.0.0")
+]
+```
 ## License
 MIT

SwiftMQTT.podspec

@@ -2,17 +2,19 @@
 Pod::Spec.new do |s|
 
     s.name         = "SwiftMQTT"
-    s.version      = "2.0.0"
+    s.version      = "3.0.0"
     s.summary      = "MQTT Client in pure Swift"
     s.description  = <<-DESC
-    MQTT Client in Swift 3.0 based on MQTT Version 3.1.1
+    MQTT Client in Swift 4.1 based on MQTT Version 3.1.1
     DESC
 
     s.homepage     = "https://github.com/aciidb0mb3r/SwiftMQTT"
     s.license      = { :type => "MIT", :file => "LICENSE" }
     s.author       = { "Ankit Agarwal" => "[email protected]" }
     s.source       = { :git => "https://github.com/aciidb0mb3r/SwiftMQTT.git", :tag => s.version.to_s }
 
+    s.swift_version = "4.1"
+
     s.ios.deployment_target = "8.0"
     s.osx.deployment_target = "10.10"
     s.tvos.deployment_target = "9.0"