Add the ability to initialise a DownView using a custom template bundle

Down.xcodeproj/project.pbxproj

@@ -64,6 +64,7 @@
 		8AFAEB071E6E331700E09B68 /* DownViewTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D41689B21CFFE28200E5802B /* DownViewTests.swift */; };
 		8AFAEB081E6E331700E09B68 /* NSAttributedStringTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D4F948DB1D00A4A800C9C0F6 /* NSAttributedStringTests.swift */; };
 		8AFAEB091E6E331700E09B68 /* StringTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = D438696B1D00D27700E95A1F /* StringTests.swift */; };
+		907C64651EC133780095FEE1 /* TestDownView.bundle in Resources */ = {isa = PBXBuildFile; fileRef = 907C64621EC120530095FEE1 /* TestDownView.bundle */; };
 		90A40A9C1EC03292004F2E91 /* Down.framework in Copy Bundled Frameworks */ = {isa = PBXBuildFile; fileRef = 8A569F401E6B3E50008BE2AC /* Down.framework */; settings = {ATTRIBUTES = (CodeSignOnCopy, RemoveHeadersOnCopy, ); }; };
 /* End PBXBuildFile section */
 
@@ -94,6 +95,7 @@
 /* Begin PBXFileReference section */
 		8A569F401E6B3E50008BE2AC /* Down.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = Down.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		8AFAEAFB1E6E32E900E09B68 /* DownTests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = DownTests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
+		907C64621EC120530095FEE1 /* TestDownView.bundle */ = {isa = PBXFileReference; lastKnownFileType = "wrapper.plug-in"; path = TestDownView.bundle; sourceTree = "<group>"; };
 		90A40A951EC02FF6004F2E91 /* Down-Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = "Down-Info.plist"; sourceTree = "<group>"; };
 		90A40A961EC02FF6004F2E91 /* DownTests-Info.plist */ = {isa = PBXFileReference; lastKnownFileType = text.plist.xml; path = "DownTests-Info.plist"; sourceTree = "<group>"; };
 		90A40A981EC0309A004F2E91 /* Deployment-Targets.xcconfig */ = {isa = PBXFileReference; lastKnownFileType = text.xcconfig; path = "Deployment-Targets.xcconfig"; sourceTree = "<group>"; };
@@ -171,6 +173,14 @@
 /* End PBXFrameworksBuildPhase section */
 
 /* Begin PBXGroup section */
+		907C64611EC120530095FEE1 /* Fixtures */ = {
+			isa = PBXGroup;
+			children = (
+				907C64621EC120530095FEE1 /* TestDownView.bundle */,
+			);
+			path = Fixtures;
+			sourceTree = "<group>";
+		};
 		90A40A971EC0309A004F2E91 /* Configurations */ = {
 			isa = PBXGroup;
 			children = (
@@ -232,6 +242,7 @@
 			children = (
 				D4201EC51CFA59A5008EEC6E /* BindingTests.swift */,
 				D41689B21CFFE28200E5802B /* DownViewTests.swift */,
+				907C64611EC120530095FEE1 /* Fixtures */,
 				D4F948DB1D00A4A800C9C0F6 /* NSAttributedStringTests.swift */,
 				D438696B1D00D27700E95A1F /* StringTests.swift */,
 			);
@@ -377,6 +388,7 @@
 			buildConfigurationList = 8AFAEB031E6E32E900E09B68 /* Build configuration list for PBXNativeTarget "DownTests" */;
 			buildPhases = (
 				8AFAEAF71E6E32E900E09B68 /* Sources */,
+				907C64641EC133740095FEE1 /* Resources */,
 				8AFAEAF81E6E32E900E09B68 /* Frameworks */,
 				90A40A9B1EC03282004F2E91 /* Copy Bundled Frameworks */,
 			);
@@ -437,6 +449,14 @@
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};
+		907C64641EC133740095FEE1 /* Resources */ = {
+			isa = PBXResourcesBuildPhase;
+			buildActionMask = 2147483647;
+			files = (
+				907C64651EC133780095FEE1 /* TestDownView.bundle in Resources */,
+			);
+			runOnlyForDeploymentPostprocessing = 0;
+		};
 /* End PBXResourcesBuildPhase section */
 
 /* Begin PBXSourcesBuildPhase section */

Source/Views/DownView.swift

@@ -20,12 +20,22 @@ open class DownView: WKWebView {
      - parameter frame:               The frame size of the web view
      - parameter markdownString:      A string containing CommonMark Markdown
      - parameter openLinksInBrowser:  Whether or not to open links using an external browser
+     - parameter templateBundle:      Optional custom template bundle. Leaving this as `nil` will use the bundle included with Down.
      - parameter didLoadSuccessfully: Optional callback for when the web content has loaded successfully
 
      - returns: An instance of Self
      */
-    public init(frame: CGRect, markdownString: String, openLinksInBrowser: Bool = true, didLoadSuccessfully: DownViewClosure? = nil) throws {
+    public init(frame: CGRect, markdownString: String, openLinksInBrowser: Bool = true, templateBundle: Bundle? = nil, didLoadSuccessfully: DownViewClosure? = nil) throws {
         self.didLoadSuccessfully = didLoadSuccessfully
+
+        if let templateBundle = templateBundle {
+            self.bundle = templateBundle
+        } else {
+            let classBundle = Bundle(for: DownView.self)
+            let url = classBundle.url(forResource: "DownView", withExtension: "bundle")!
+            self.bundle = Bundle(url: url)!
+        }
+
         super.init(frame: frame, configuration: WKWebViewConfiguration())
 
         if openLinksInBrowser || didLoadSuccessfully != nil { navigationDelegate = self }
@@ -58,11 +68,7 @@ open class DownView: WKWebView {
 
     // MARK: - Private Properties
 
-    fileprivate let bundle: Bundle = {
-        let bundle = Bundle(for: DownView.self)
-        let url = bundle.url(forResource: "DownView", withExtension: "bundle")!
-        return Bundle(url: url)!
-    }()
+    let bundle: Bundle
 
     fileprivate lazy var baseURL: URL = {
         return self.bundle.url(forResource: "index", withExtension: "html")!

Tests/DownViewTests.swift

@@ -65,6 +65,33 @@ class DownViewTests: XCTestCase {
         }
     }
 
+    func testInstantiationWithCustomTemplateBundle() {
+        let expect1 = expectation(description: "DownView accepts and uses a custom theme bundle")
+        guard
+            let bundle = Bundle(for: type(of: self)).url(forResource: "TestDownView", withExtension: "bundle"),
+            let templateBundle = Bundle(url: bundle)
+        else {
+            XCTFail("Test template bundle not found in test target!")
+            return
+        }
+
+        var downView: DownView?
+        downView = try? DownView(frame: .zero, markdownString: "## [Down](https://github.com/iwasrobbed/Down)", templateBundle: templateBundle, didLoadSuccessfully: {
+            self._pageContents(for: downView!) { (htmlString) in
+                XCTAssertTrue(htmlString!.contains("css/down.min.css"))
+                XCTAssertTrue(htmlString!.contains("https://github.com/iwasrobbed/Down"))
+                XCTAssertTrue(htmlString!.contains("But also, custom HTML!"))
+
+                expect1.fulfill()
+            }
+        })
+
+        waitForExpectations(timeout: 10) { (error: Error?) in
+            if let error = error {
+                XCTFail("waitForExpectationsWithTimeout errored: \(error)")
+            }
+        }
+    }
 }
 
 fileprivate extension DownViewTests {

Tests/Fixtures/TestDownView.bundle/index.html

@@ -0,0 +1,15 @@
+<!DOCTYPE html>
+<html>
+<head>
+    <meta charset="utf-8">
+    <meta name="viewport" content="width=640"/>
+    <link charset="utf-8" href="css/down.min.css" rel="stylesheet">
+    <script charset="utf-8" src="js/highlight.min.js" type="text/javascript"></script>
+    <script charset="utf-8" src="js/down.js" type="text/javascript"></script>
+    <title></title>
+</head>
+<body>
+    DOWN_HTML
+    But also, custom HTML!
+</body>
+</html>

Tests/Fixtures/TestDownView.bundle/js/down.js

@@ -0,0 +1 @@
+hljs.initHighlightingOnLoad();