import Cocoa
import Quartz // QLPreviewingController
import WebKit // WebView
import Markdown // Document, HTMLFormatter
//import os // OSLog
//
//private let log = OSLog(subsystem: Bundle.main.bundleIdentifier!, category: "preview-plugin")
extension URL {
/// Folder where user can mofifications to html template
static let UserModDir: URL? =
FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first
/// Returns `true` if file or folder exists.
@inlinable func exists() -> Bool {
FileManager.default.fileExists(atPath: self.path)
}
}
class PreviewViewController: NSViewController, QLPreviewingController, WKNavigationDelegate {
var url: URL? = nil
var html: String? = nil
override var nibName: NSNib.Name? {
return NSNib.Name("PreviewViewController")
}
/// Load resource file either from user documents dir (if exists) or app bundle (default).
func bundleFile(filename: String, ext: String) -> URL {
if let userFile = URL.UserModDir?.appendingPathComponent(filename + "." + ext, isDirectory: false), userFile.exists() {
return userFile
}
return Bundle.main.url(forResource: filename, withExtension: ext)!
}
func preparePreviewOfFile(at url: URL) async throws {
let md = try Document(parsing: url)
let ver = Bundle.main.infoDictionary?["CFBundleShortVersionString"] as! String
let buildVer = Bundle.main.infoDictionary?["CFBundleVersion"] as! String
self.url = url
self.html = """
\(HTMLFormatter.format(md))
"""
// write debug output
//try? html!.write(to: URL.UserModDir!.appendingPathComponent("debug.html", isDirectory: false), atomically: true, encoding: .utf8)
// create web view UI
let web = WKWebView(frame: self.view.bounds)
web.navigationDelegate = self
web.autoresizingMask = [.width, .height]
self.view.addSubview(web)
// allow read access to all files under root "/"
let emtpy = Bundle.main.url(forResource: "empty", withExtension: "txt")!
web.loadFileURL(emtpy, allowingReadAccessTo: URL(string: "file:///")!)
// loadHTMLString must wait until previous request is fully loaded
// see delegate method below
}
func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
if webView.url?.lastPathComponent == "empty.txt" {
webView.loadHTMLString(html!, baseURL: url)
html = nil // free up memory
}
}
// this should open links in external browser but it doesnt
// func webView(_ webView: WKWebView, decidePolicyFor navigationAction: WKNavigationAction, decisionHandler: @escaping @MainActor (WKNavigationActionPolicy) -> Void) {
// if navigationAction.navigationType == .linkActivated,
// let url = navigationAction.request.url {
// os_log(.debug, log: log, "open url %{public}@", String(describing: url))
// NSWorkspace.shared.open(url)
// decisionHandler(.cancel)
// } else {
// decisionHandler(.allow)
// }
// }
}