Input Type=File Not Working in Webview of Os X Application

Input type=file not working in WebView of OS X application

I have not worked with this myself, but from puzzling bits and pieces together this seems to do what you'd like.

First...I'm using a WKWebView. That is declared and initialised with a local HTML file like so:

import Cocoa
import WebKit

class ViewController: NSViewController {

    let webview: WKWebView = WKWebView()

    override func viewDidLoad() {
        super.viewDidLoad()
        webview.autoresizingMask = [.viewWidthSizable, .viewHeightSizable]
        webview.frame = view.bounds
        webview.uiDelegate = self
        view.addSubview(webview)

        let fileURL = URL(fileURLWithPath: "/Users/myuserhere/Desktop/index.html")
        webview.loadFileURL(fileURL, allowingReadAccessTo: fileURL)
     }
  }

The interesting part is webview.uiDelegate. This promises that we will conform to the WKUIDelegate protocol documented here. As it says:

The WKUIDelegate class provides methods for presenting native user interface elements on behalf of a webpage.

One of the methods you can implement is runOpenPanelWithParameters:

If you implement this method, you promise that you will present a file upload panel and call the callback method of this method with the outcome of what the user selected. Remember to also call the callback method when the user presses cancel.

Here is a quick and dirty example:

extension ViewController: WKUIDelegate {
    func webView(_ webView: WKWebView, runOpenPanelWith parameters: WKOpenPanelParameters, initiatedByFrame frame: WKFrameInfo, completionHandler: @escaping ([URL]?) -> Void) {
        let openPanel = NSOpenPanel()
        openPanel.canChooseFiles = true
        openPanel.begin { (result) in
            if result == NSApplication.ModalResponse.OK {
                if let url = openPanel.url {
                    completionHandler([url])
                }
            } else if result == NSApplication.ModalResponse.cancel {
                completionHandler(nil)
            }
        }
    }
}

Hopefully that gives you something to get started with.

Bonus Material

Here are some links that helped me:

How to upload files from WKWebView

How to implement the delegate method

How to create a NSOpenPanel in Swift

For iOS (asked by @DarshanMothreja)

I tried gluing together a simple program to do the same on iOS. I hope it is useful to you @DarshanMothreja

HTML
A file called index.html is added to the Xcode project. The content looks like this:

<!DOCTYPE html>
<html lang="en" dir="ltr">
  <head>
    <meta charset="utf-8">
    <title>Test</title>
    <meta name="viewport" content="width=device-width, initial-scale=1">
  </head>
  <body>
    <label for="file">File goes here</label>
    <input type="file" name="file" value="File">
  </body>
</html>

How can you get input file to work in a WKWebView?

This is a known bug in WKWebView.

https://bugs.webkit.org/show_bug.cgi?id=137759

Upload file using input type=file with WKWebView does not open file dialog

Implemented the UIDelegate like this.

func webView(_ webView: WKWebView, runOpenPanelWith parameters: WKOpenPanelParameters, initiatedByFrame frame: WKFrameInfo, completionHandler: @escaping ([URL]?) -> Void) {
    let openPanel = NSOpenPanel()
    openPanel.canChooseFiles = true
    openPanel.begin { (result) in
        if result == NSApplication.ModalResponse.OK {
            if let url = openPanel.url {
                completionHandler([url])
            }
        } else if result == NSApplication.ModalResponse.cancel {
            completionHandler(nil)
        }
    }
}

Input Type=File Not Working in Webview of Os X Application