WKWebView does load resources from local document folder

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This is a simplified version of what I have used to load local files in a project of mine (iOS 10, Swift 3). I have just updated my code (7.5.2017) after testing it out again on iOS 10.3.1 and iPhone 7+ as requested by Raghuram and Fox5150 in the comments.

I just created a completely new project and this is the folder structure:enter image description here

Update 19.04.2018: Added a new feature to download a .zip with HTML, CSS, JS files, unzip it in /Documents/ (Alamofire + Zip) and then load those files into the webView. You can find it in the GitHub sample project as well. Again, feel free to fork & star! 🙂

Update 08.02.2018: finally added a GitHub sample project, which also includes a local JavaScript file. Feel free to fork & star! 🙂

Version 1 with webView.loadFileURL()

ViewController.swift

import UIKit
import WebKit
class ViewController: UIViewController, WKNavigationDelegate {
    override func viewDidLoad() {
        super.viewDidLoad()
        let webView = WKWebView()
        let htmlPath = Bundle.main.path(forResource: "index", ofType: "html")
        let htmlUrl = URL(fileURLWithPath: htmlPath!, isDirectory: false)
        webView.loadFileURL(htmlUrl, allowingReadAccessTo: htmlUrl)
        webView.navigationDelegate = self
        view = webView
    }
}

Version 2 with webView.loadHTMLString()

ViewController.swift

import UIKit
import WebKit
class ViewController: UIViewController, WKNavigationDelegate {
    override func viewDidLoad() {
        super.viewDidLoad()
        let webView = WKWebView()
        let htmlPath = Bundle.main.path(forResource: "index", ofType: "html")
        let folderPath = Bundle.main.bundlePath
        let baseUrl = URL(fileURLWithPath: folderPath, isDirectory: true)
        do {
            let htmlString = try NSString(contentsOfFile: htmlPath!, encoding: String.Encoding.utf8.rawValue)
             webView.loadHTMLString(htmlString as String, baseURL: baseUrl)
        } catch {
            // catch error
        }
        webView.navigationDelegate = self
        view = webView
    }
}

Gotchas to look out for:

  • Make sure that your local html/js/css files are in Project -> Target -> Build Phases -> Copy Bundle Resources
  • Make sure that your html files don’t reference relative paths e.g. css/styles.css because iOS will flatten your file structure and styles.css will be on the same level as index.html so write <link rel="stylesheet" type="text/css" href="https://stackoverflow.com/questions/39336235/styles.css"> instead

Given the 2 versions and the gotchas here are my html/css files from the project:

web/index.html

<!DOCTYPE html>
<html>
    <head>
        <meta charset="utf-8">
    <title>Offline WebKit</title>
    <link rel="stylesheet" type="text/css" href="https://stackoverflow.com/questions/39336235/styles.css">
  </head>
  <body>
    <h1 id="webkit-h1">Offline WebKit!</h1>
  </body>
</html>

web/css/styles.css

#webkit-h1 {
  font-size: 80px;
  color: lightblue;
}

If somebody wants a GitHub sample project, tell me in the comments section and I’ll upload it.

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