WKWebView LayoutConstraints issue

Question

I have created a simple webview app. But there is a small problem and I can not fix it. It loads the first page without issue.

When I click to the first input, the program crashes and the error code is below:

2017-10-28 23:50:54.289690+0400 BFI Schools[68425:3885613] [LayoutConstraints] Unable to simultaneously satisfy constraints.
Probably at least one of the constraints in the following list is one you don't want. 
Try this: 
    (1) look at each constraint and try to figure out which you don't expect; 
    (2) find the code that added the unwanted constraint or constraints and fix it. 
(Note: If you're seeing NSAutoresizingMaskLayoutConstraints that you don't understand, refer to the documentation for the UIView property translatesAutoresizingMaskIntoConstraints)

My code is below:

//
//  ViewController.swift
//  BFI Schools
//
//  Created by Kamandar Abdullayev on 10/28/17.
//  Copyright © 2017 ROOM404.AZ. All rights reserved.
//

import UIKit
import WebKit

class ViewController: UIViewController , UIWebViewDelegate {
    @IBOutlet weak var webView: UIWebView!
    @IBOutlet weak var spinner: UIActivityIndicatorView!

    override func viewDidLoad() {
        super.viewDidLoad()

        view.translatesAutoresizingMaskIntoConstraints=false

        let url = URL(string: "https://www.parent.e-hism.co")!
        let request = URLRequest(url: url)

        if Reachability.isConnectedToNetwork() == true {
            webView.loadRequest(request)
        } else {
            let alert = UIAlertView(title: "No Internet Connection", message: "Make sure your device is connected to the internet.", delegate: nil, cancelButtonTitle: "OK")
            alert.show()
        }
    }

    func webViewDidStartLoad(_ : UIWebView) {
        spinner.startAnimating()
    }

    func webViewDidFinishLoad(_ : UIWebView) {
        spinner.stopAnimating()
    }
}

I have tried all help that I find on the Internet, but no luck.

Are you sure about the crash? Auto layout errors don't really cause crashes. — Jonny
– Jonny, Commented Nov 20, 2018 at 1:02

Jano · Accepted Answer · 2018-07-23 09:39:20Z

9

Based on the following captures from Reveal, it seems like an Auto Layout issue in Apple’s code. I bet they will fix it at some point.

answered Jul 23, 2018 at 9:39

Jano

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2 Comments

Waylan Sands Over a year ago

Issue persists in 2021

xed-euteon Over a year ago

I've seen many answers that refers to the keyboard, the answer is yes and no. I've been facing this issue for quite a while by now, the issue is not the keyboard its the toolbar that comes with it just as @Jano mentioned, in the following link you will find a hackey workaround to hide that toolbar, once its removed the issue should go away. the answer: stackoverflow.com/a/57226420

Sander · Accepted Answer · 2017-10-28 21:51:15Z

2

In general you should follow next flow

Add webView as a subview to UIViewController's view (you might have done it in XIB or Storyboard)
Add Autolayout constraints between webView and UIViewController's view in code or in Interface Builder
Also, please remove

view.translatesAutoresizingMaskIntoConstraints=false

If everything about is OK, please attach your XIB or Storyboard.

Update Here is my ViewController that shows WKWebView only.

    class ViewController: UIViewController {

        lazy var webView: WKWebView = {
            let webView = WKWebView(frame: .zero)
            webView.translatesAutoresizingMaskIntoConstraints = false
            return webView
        }()

        override func viewDidLoad() {
            super.viewDidLoad()

            // layout code
            view.addSubview(webView)
            view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "V:|[webView]|", options: [], metrics: nil, views: ["webView": webView]))
            view.addConstraints(NSLayoutConstraint.constraints(withVisualFormat: "H:|[webView]|", options: [], metrics: nil, views: ["webView": webView]))

            // and then code to load request

        }
    }

edited Oct 28, 2017 at 21:51

answered Oct 28, 2017 at 20:06

Sander

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8 Comments

maxileft Over a year ago

i have tried your suggestion, but no luck again. the first page opens without problem, but wheni click to inpub box, boom. ihave changed the url to another website, the same problem there too, first page opens, but after input box click crashes. And keyboard not showing also.

Sander Over a year ago

Can you attach your XIB or Storyboard screenshot.

maxileft Over a year ago

storyboard screenshot . import UIKit import WebKit class ViewController: UIViewController , WKNavigationDelegate{ var webView : WKWebView! override func viewDidLoad() { super.viewDidLoad() let site = "parent.e-hism.co" let url = NSURL(string: site) let request = NSURLRequest(url: url! as URL) webView = WKWebView(frame: self.view.frame) webView.navigationDelegate = self webView.load(request as URLRequest) self.view.addSubview(webView) self.view.sendSubview(toBack: webView) } }

Sander Over a year ago

Updated my answer. Included my example of such UIViewController

maxileft Over a year ago

now im gettin error: System group container for systemgroup.com.apple.configurationprofiles path is /Users/maxileft/Library/Developer/CoreSimulator/Devices/D19FA1A9-B940-4E84-8665-1835B61C10B9/data/Containers/Shared/SystemGroup/systemgroup.com.apple.configurationprofiles 2017-10-29 14:37:47.697976+0400 BFI Schools[76569:4189931] *** Terminating app due to uncaught exception 'NSUnknownKeyException', reason: '[<BFI_Schools.ViewController 0x7fa7a7509820> setValue:forUndefinedKey:]: this class is not key value coding-compliant for the key webView.'

|

Yasper · Accepted Answer · 2018-04-10 23:48:14Z

2

It might be interesting to note this happens to a lot of people. I have a clean project running, no additional controls and get the same problem: layout constraints when clicking Search (keyboard popup).

It might be indicated as an iOS 11 bug here: WKWebView constrains issue when keyboard pops up

answered Apr 10, 2018 at 23:48

Yasper

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1 Comment

nickdnk Over a year ago

This is still broken. GG Apple.

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