Skip to content

Instantly share code, notes, and snippets.

@pkuecuekyan
Last active June 17, 2024 17:44
Show Gist options
  • Save pkuecuekyan/f70096218a6b969e0249427a7d324f91 to your computer and use it in GitHub Desktop.
Save pkuecuekyan/f70096218a6b969e0249427a7d324f91 to your computer and use it in GitHub Desktop.
Adjust height of WKWebView frame based on scrollHeight of the webView's content
// Since the WKWebView has no sizeToFit() method, increase the frame height of the webView to
// match the height of the content's scrollHeight
//
// The WKWebView's `navigationDelegate` property needs to be set for the delegate method to be called
func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
if webView.isLoading == false {
webView.evaluateJavaScript("document.body.scrollHeight", completionHandler: { [weak self] (result, error) in
if let height = result as? CGFloat {
webView.frame.size.height += height
}
})
}
}
@yunchiri
Copy link

Thanks!!

@hlung
Copy link

hlung commented Apr 17, 2018

Nice! For me, instead of setting the webView.frame, I set autolayout intrinsicContentSize.

import UIKit
import WebKit

class ArticleWebView: WKWebView {

  init(frame: CGRect) {
    let configuration = WKWebViewConfiguration()
    super.init(frame: frame, configuration: configuration)
    self.navigationDelegate = self
  }

  required init?(coder: NSCoder) {
    fatalError("init(coder:) has not been implemented")
  }

  override var intrinsicContentSize: CGSize {
    return self.scrollView.contentSize
  }

}

extension ArticleWebView: WKNavigationDelegate {

  func webView(_ webView: WKWebView, didFinish navigation: WKNavigation!) {
    webView.evaluateJavaScript("document.readyState", completionHandler: { (_, _) in
      webView.invalidateIntrinsicContentSize()
    })
  }

}

@neugierige
Copy link

I'm getting back a height value that is way bigger than the actual size of my content. Any ideas why that might be happening?

@NSAmit
Copy link

NSAmit commented Sep 24, 2018

Me too getting way bigger height than the actual content.

@k-marin
Copy link

k-marin commented Nov 25, 2018

initalize your webview with configuration and inject the viewport meta tag

func webViewConfiguration() -> WKWebViewConfiguration {
let configuration = WKWebViewConfiguration()
configuration.userContentController = userContentController()
return configuration
}

private func userContentController() -> WKUserContentController {
    let controller = WKUserContentController()
    controller.addUserScript(viewPortScript())
    return controller
}


private func viewPortScript() -> WKUserScript {
    let viewPortScript = """
        var meta = document.createElement('meta');
        meta.setAttribute('name', 'viewport');
        meta.setAttribute('content', 'width=device-width');
        meta.setAttribute('initial-scale', '1.0');
        meta.setAttribute('maximum-scale', '1.0');
        meta.setAttribute('minimum-scale', '1.0');
        meta.setAttribute('user-scalable', 'no');
        document.getElementsByTagName('head')[0].appendChild(meta);
    """
    return WKUserScript(source: viewPortScript, injectionTime: .atDocumentEnd, forMainFrameOnly: true)
}

@ShivamPokhriyal
Copy link

@neugierige @NSAmit Did you manage to get actual height? I too am getting bigger height value.

@LGFox
Copy link

LGFox commented Apr 4, 2019

@ShivamPokhriyal, If you get too big value - try to add tag as @k-marin proposed above. That works for me.

Copy link

ghost commented Jul 5, 2019

thx

@ARIFCSE10
Copy link

how to get actual height if I have to set initial scale to other than 1 ?

@anandabayu
Copy link

thanks

@gvsharma
Copy link

Really helpful thanks

@emilyvon
Copy link

This is exactly what I'm looking for, thank you :]

@josipbernat
Copy link

josipbernat commented Mar 25, 2020

If someone needs it, here is ObjC version of viewport meta tag injection.

- (WKUserContentController *)userContentController {
    WKUserContentController *controller = [[WKUserContentController alloc] init];
    [controller addUserScript:[self userScript]];
    return controller;
}

- (WKUserScript *)userScript {

    NSString *viewPortScript = @"var meta = document.createElement('meta'); meta.setAttribute('name', 'viewport'); meta.setAttribute('content', 'width=device-width, shrink-to-fit=YES'); meta.setAttribute('initial-scale', '1.0'); meta.setAttribute('maximum-scale', '1.0'); meta.setAttribute('minimum-scale', '1.0'); meta.setAttribute('user-scalable', 'no'); document.getElementsByTagName('head')[0].appendChild(meta);";

    return [[WKUserScript alloc] initWithSource:viewPortScript injectionTime:WKUserScriptInjectionTimeAtDocumentEnd forMainFrameOnly:YES];
}

@mogelbuster
Copy link

mogelbuster commented Apr 23, 2020

If you're using loadHTMLString(_:baseURL:) method on WKWebView to display your content and getting way too big of a height value, a possibly simpler fix than using javascript to inject the viewport meta tag is to just include it right at the beginning of the html string. This was all I needed:

"<meta name='viewport' content='width=device-width, shrink-to-fit=YES'>"

But if that doesn't work, you could always try the full string from above:

"<meta name='viewport' content='width=device-width, shrink-to-fit=YES' initial-scale='1.0' maximum-scale='1.0' minimum-scale='1.0' user-scalable='no'>"

My html string didn't have a head tag, so I just put it at the very beginning. But if your string does have a head tag, then put this meta tag in there.

@pallavi10aggarwal
Copy link

@mogelbuster I am using loadHTMLString(_:baseURL:) method on WKWebView to display my content and getting way too big of a height value , I tried @k-marvin and ur solutions but no luck , kindly suggest

@standinga
Copy link

I was also getting height too big inside the UITableViewCells, the suggested solutions didn't work consistently. In my case querying specific div instead of the whole body seems to work fine.
webView.evaluateJavaScript("document.getElementById('publication').scrollHeight") { height, error in ... }
Where my top

element has id='publication'

@AD-Paladins
Copy link

thanks! 👯

@ruisantos78
Copy link

ruisantos78 commented Mar 27, 2021

The problem for me was the document.body.width, even if meta tag still very small...
So I fix running a script before:
document.body.style.width = '{width}px'

when width it's the current resolution of my device screen...

after than, when I call the "document.body.scrollHeight" works like a charm...

I use Xamarin by the way...

  public override async void DidFinishNavigation(WKWebView webView, WKNavigation navigation) {
        if (renderer?.Element is WebListItemView view)
        {
            webView.EvaluateJavaScript("document.readyState", async (completed, error) =>
            {
                if (completed is null) return;
  
                await webView.EvaluateJavaScriptAsync($"document.body.style.width = '{view.Width}px'");
                var offsetHeight = await webView.EvaluateJavaScriptAsync("document.body.scrollHeight");
                if (offsetHeight is Foundation.NSNumber height)
                {
                    view.HeightRequest = height.DoubleValue;
  
                    if (view.Parent is ViewCell cell) cell.ForceUpdateSize();
                }
            });
        }
  }

@elmyn
Copy link

elmyn commented Nov 6, 2021

I'm getting too small content with view port.

@vishalkevin11
Copy link

Thanks a lot. This works like a charm.

@kneskoromny
Copy link

kneskoromny commented Mar 12, 2024

The problem for me was the document.body.width, even if meta tag still very small...
So I fix running a script before:
document.body.style.width = '{width}px'

Thanx! It's work for me. Your answer save me :)

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment