Fix view controller not being released (#8)

Fixes #7

PreviewExtension/PreviewViewController.swift

@@ -113,11 +113,11 @@ class PreviewViewController: NSViewController, QLPreviewingController, WKUIDeleg
   }
 
   deinit {
-    log.debug("deinit PreviewViewController")
+    log.debug("deinit \(self)")
   }
 
   override func loadView() {
-    log.debug("loadView")
+    log.debug("\(self) loadView")
     view = webView
 
     webView.uiDelegate = self
@@ -168,6 +168,13 @@ class PreviewViewController: NSViewController, QLPreviewingController, WKUIDeleg
     webView.loadFileURL(configuration.pageURL, allowingReadAccessTo: configuration.pageURL)
   }
 
+  override func viewDidDisappear() {
+    super.viewDidDisappear()
+    // Break a strong reference that prevents the view controller from being released
+    // https://forums.developer.apple.com/forums/thread/713062?answerId=726937022#726937022
+    webView.configuration.userContentController.removeAllScriptMessageHandlers()
+  }
+
   func preparePreviewOfFile(at url: URL, completionHandler: @escaping (Error?) -> Void) {
     log.info("begin preparing file", metadata: ["url": "\(url)"])
     assert(previewedFileURL == nil)

package.json

@@ -1,6 +1,6 @@
 {
   "name": "quicklookjs",
-  "version": "1.0.0",
+  "version": "1.0.1",
   "description": "Quick Look plugin for web-based previews",
   "homepage": "https://github.com/jtbandes/quicklookjs#readme",
   "author": "Jacob Bandes-Storch",