Modify completion as Result type

Cartfile.private

@@ -1 +1 @@
-github "AliSoftware/OHHTTPStubs" "6.0.0"
+github "AliSoftware/OHHTTPStubs" "8.0.0"

Cartfile.resolved

@@ -1 +1 @@
-github "AliSoftware/OHHTTPStubs" "6.0.0"
+github "AliSoftware/OHHTTPStubs" "8.0.0"

OpenGraph.xcodeproj/project.pbxproj

@@ -405,7 +405,7 @@
 				SKIP_INSTALL = YES;
 				SUPPORTED_PLATFORMS = "macosx iphoneos iphonesimulator";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 5.0;
 				TVOS_DEPLOYMENT_TARGET = 9.0;
 				WATCHOS_DEPLOYMENT_TARGET = 2.0;
 			};
@@ -435,7 +435,7 @@
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SKIP_INSTALL = YES;
 				SUPPORTED_PLATFORMS = "macosx iphoneos iphonesimulator";
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 5.0;
 				TVOS_DEPLOYMENT_TARGET = 9.0;
 				WATCHOS_DEPLOYMENT_TARGET = 2.0;
 			};
@@ -456,7 +456,7 @@
 				PRODUCT_BUNDLE_IDENTIFIER = "net.cloud-dj.OpenGraphTests";
 				PRODUCT_NAME = "$(TARGET_NAME)";
 				SWIFT_OPTIMIZATION_LEVEL = "-Onone";
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Debug;
 		};
@@ -474,7 +474,7 @@
 				LD_RUNPATH_SEARCH_PATHS = "$(inherited) @executable_path/../Frameworks @loader_path/../Frameworks";
 				PRODUCT_BUNDLE_IDENTIFIER = "net.cloud-dj.OpenGraphTests";
 				PRODUCT_NAME = "$(TARGET_NAME)";
-				SWIFT_VERSION = 4.0;
+				SWIFT_VERSION = 5.0;
 			};
 			name = Release;
 		};

OpenGraph/OpenGraph.swift

@@ -1,54 +1,39 @@
 import Foundation
 
 public struct OpenGraph {
-    public let source: [OpenGraphMetadata: String]
 
-    public static func fetch(url: URL, completion: @escaping (OpenGraph?, Error?) -> Void) {
-        let configuration = URLSessionConfiguration.default
-        let session = URLSession(configuration: configuration)
-        let task = session.dataTask(with: url, completionHandler: { (data, response, error) in
-            handleFetchResult(data: data, response: response, error: error, callback: completion)
-        })
-        task.resume()
-    }
+    public let source: [OpenGraphMetadata: String]
 
-    public static func fetch(url: URL, headers: [String:String], completion: @escaping (OpenGraph?, Error?) -> Void) {
+    public static func fetch(url: URL, headers: [String: String]? = nil, completion: @escaping (Result<OpenGraph, Error>) -> Void) {
         var mutableURLRequest = URLRequest(url: url)
-        for hkey in headers.keys {
-            let value:String! = headers[hkey]
-            if value != nil {
-                mutableURLRequest.setValue(value, forHTTPHeaderField: hkey)
-            }
+        headers?.compactMapValues { $0 }.forEach {
+            mutableURLRequest.setValue($1, forHTTPHeaderField: $0)
         }
-
         let configuration = URLSessionConfiguration.default
         let session = URLSession(configuration: configuration)
-        let task = session.dataTask(with: mutableURLRequest, completionHandler: { (data, response, error) in
-            handleFetchResult(data: data, response: response, error: error, callback: completion)
-        }) 
+        let task = session.dataTask(with: mutableURLRequest, completionHandler: { data, response, error in
+            if let error = error {
+                completion(.failure(error))
+            } else {
+                handleFetchResult(data: data, response: response, completion: completion)
+            }
+        })
         task.resume()
     }
 
-    private static func handleFetchResult(data: Data?, response: URLResponse?, error: Error?, callback: @escaping (OpenGraph?, Error?) -> Void){
-        switch (data, response, error) {
-        case (_, _, let error?):
-            callback(nil, error)
-            break
-        case (let data?, let response as HTTPURLResponse, _):
-            if !(200..<300).contains(response.statusCode) {
-                callback(nil, OpenGraphResponseError.unexpectedStatusCode(response.statusCode))
-            } else {
-                guard let htmlString = String(data: data, encoding: String.Encoding.utf8) else {
-                    callback(nil, OpenGraphParseError.encodingError)
-                    return
-                }
-
-                let og = OpenGraph(htmlString: htmlString)
-                callback(og, error)
+    private static func handleFetchResult(data: Data?, response: URLResponse?, completion: @escaping (Result<OpenGraph, Error>) -> Void) {
+        guard let data = data, let response = response as? HTTPURLResponse else {
+            return
+        }
+        if !(200..<300).contains(response.statusCode) {
+            completion(.failure(OpenGraphResponseError.unexpectedStatusCode(response.statusCode)))
+        } else {
+            guard let htmlString = String(data: data, encoding: String.Encoding.utf8) else {
+                completion(.failure(OpenGraphParseError.encodingError))
+                return
             }
-            break
-        default:
-            break
+            let og = OpenGraph(htmlString: htmlString)
+            completion(.success(og))
         }
     }
 

README.md

@@ -3,35 +3,39 @@
 OpenGraph is a Swift wrapper for the OGP ([Open Graph protocol](http://ogp.me/)).
 You can fetch OpenGraph,then you can access the attributes with subscript and the key provided by enum type.
 ```swift
-OpenGraph.fetch(url) { og, error in
-    print(og?[.title]) // => og:title of the web site
-    print(og?[.type])  // => og:type of the web site
-    print(og?[.image]) // => og:image of the web site
-    print(og?[.url])   // => og:url of the web site
+OpenGraph.fetch(url: url) { result in
+    switch result {
+    case .success(let og):
+        print(og[.title]) // => og:title of the web site
+        print(og[.type])  // => og:type of the web site
+        print(og[.image]) // => og:image of the web site
+        print(og[.url])   // => og:url of the web site
+    case .failure(let error):
+        print(error)
+    }
 }
 ```
 
 If you want to use Rx interface, use an extension below.
 ```swift
-extension OpenGraph {
-    static func rx_fetch(url: URL?) -> Observable<OpenGraph?> {
+extension Reactive where Base: OpenGraph {
+    static func fetch(url: URL?) -> Observable<OpenGraph> {
         return Observable.create { observer in
             guard let url = url else {
                 observer.onCompleted()
                 return Disposables.create()
             }
-
-            OpenGraph.fetch(url: url) { og, err in
-                if let og = og {
+
+            OpenGraph.fetch(url: url) { result in
+                switch result {
+                case .success(let og):
                     observer.onNext(og)
+                case .failure(let error):
+                    observer.onError(error)
                 }
-                if let err = err {
-                    observer.onError(err)
-                }
-
                 observer.onCompleted()
             }
-            
+
             return Disposables.create()
         }
     }

Tests/OpenGraphTests.swift

@@ -33,9 +33,11 @@ class OpenGraphTests: XCTestCase {
         var og: OpenGraph!
         var error: Error?
         let headers = ["User-Agent": "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/51.0.2704.103 Safari/537.36"]
-        OpenGraph.fetch(url: url, headers: headers) { (_og, _error) in
-            og = _og
-            error = _error
+        OpenGraph.fetch(url: url, headers: headers) { result in
+            switch result {
+            case .success(let _og): og = _og
+            case .failure(let _error): error = _error
+            }
             responseArrived.fulfill()
         }
 
@@ -57,9 +59,11 @@ class OpenGraphTests: XCTestCase {
         let url = URL(string: "https://www.example.com")!
         var og: OpenGraph!
         var error: Error?
-        OpenGraph.fetch(url: url) { _og, _error in
-            og = _og
-            error = _error
+        OpenGraph.fetch(url: url) { result in
+            switch result {
+            case .success(let _og): og = _og
+            case .failure(let _error): error = _error
+            }
             responseArrived.fulfill()
         }
 
@@ -82,9 +86,11 @@ class OpenGraphTests: XCTestCase {
         let url = URL(string: "https://www.example.com")!
         var og: OpenGraph!
         var error: Error?
-        OpenGraph.fetch(url: url) { _og, _error in
-            og = _og
-            error = _error
+        OpenGraph.fetch(url: url) { result in
+            switch result {
+            case .success(let _og): og = _og
+            case .failure(let _error): error = _error
+            }
             responseArrived.fulfill()
         }
 
@@ -110,9 +116,11 @@ class OpenGraphTests: XCTestCase {
         let url = URL(string: "https://www.example.com")!
         var og: OpenGraph?
         var error: Error?
-        OpenGraph.fetch(url: url) { _og, _error in
-            og = _og
-            error = _error
+        OpenGraph.fetch(url: url) { result in
+            switch result {
+            case .success(let _og): og = _og
+            case .failure(let _error): error = _error
+            }
             responseArrived.fulfill()
         }
 
@@ -144,9 +152,11 @@ class OpenGraphTests: XCTestCase {
         let url = URL(string: "https://www.example.com")!
         var og: OpenGraph?
         var error: Error?
-        OpenGraph.fetch(url: url) { _og, _error in
-            og = _og
-            error = _error
+        OpenGraph.fetch(url: url) { result in
+            switch result {
+            case .success(let _og): og = _og
+            case .failure(let _error): error = _error
+            }
             responseArrived.fulfill()
         }