Swift4 app crashes when loading local HTML

Question

While working on a web app for weeks, I used a external URL in my (WKWebView) web view. Now I'm moving towards production I want to embed the webapp and load a local webpage.

I simply moved from

let url = URL(string: "http://hidden-url.com/")
self.webView!.load(URLRequest(url: url!))

To

let url = URL(string: Bundle.main.path(forResource: "index_prod", ofType: "html")!)
self.webView!.load(URLRequest(url: url!))

But this causes my app to crash. I'm sure the file is loaded correctly and a print before, in-between and after the lines will appear in the console.

The error: Thread 1: EXC_BAD_ACCESS (code=1, address=0x10)

I double checked it, it's listed in my project hierarchy and at 'Copy Bundle Resources' in the Build Phases — Jeffrey Lanters ジェフリー, Dec 04 '17 at 13:03
Loading the file does not catch any exceptions, loading it into the web view will. — Jeffrey Lanters ジェフリー, Dec 04 '17 at 13:13
https://stackoverflow.com/questions/24882834/wkwebview-not-loading-local-files-under-ios-8 https://stackoverflow.com/questions/39336235/wkwebview-does-load-resources-from-local-document-folder You either have to use `loadHTMLString()` or `loadFileURL(url:allowingReadAccessTo:)`. — Larme, Dec 04 '17 at 15:56
@Larme true, but that question is about Objective-C mine is about Swift. — Jeffrey Lanters ジェフリー, Dec 04 '17 at 16:32
@JeffreyLanters Both of my linked question have Swift code. Both explain WHY your code doesn't work and why you need to use a different approach. They may not be Swift 4 compliant, but the explanation in itself should be enough. — Larme, Dec 04 '17 at 16:41

Suhit Patil · Accepted Answer · 2017-12-04T17:11:01.227

You need to load the string content from the file, use contentsOfFile method to get the string and use loadHTMLString method of webview, print the error or create some enum which shows the error

enum WebError: Swift.Error {
    case fileNotFound(name: String)
    case parsing(contentsOfFile: String)
}

guard let url = Bundle.main.path(forResource: "index_prod", ofType: "html") else {
   throw WebError.fileNotFound(name: file) // throw file not found error 
}

do {
      let html = try String(contentsOfFile: url)
      self.webView.loadHTMLString(html, baseURL: Bundle.main.bundleURL)
} catch {
      throw WebError.parsingError(contentsOfFile: file) 
}

Swift4 app crashes when loading local HTML

1 Answers1