I have a webView in my ViewController. I have created a BullsEye.html file in my project and I want to show that html file in my web view. Following is my code
if let url = Bundle.main.url(forResource: "BullsEye",
withExtension: "html") {
if let htmlData = try? Data(contentsOf: url) {
let baseURL = URL(fileURLWithPath: Bundle.main.bundlePath)
webView.load(htmlData, mimeType: "text/html",
textEncodingName: "UTF-8", baseURL: baseURL)
}
}
The above code is written in viewDidLoad. What am I missing?
I ran your code as is and was able to make things work as seen here after changing the webView loader code. This tells me you likely have a UIWebView lurking somewhere, likely your view in storyboard.
I would recommend you make sure that you are consistently using WKWebView throughout:
Import WebKit in your class file
Have a valid output link to it if you are using a storyboard
If using a storyboard, ensure that you are using WKWebView and not the deprecated UIWebView
There is no problem with your source code itself, I think.
But maybe does Bundle.main.url(forResource: "BullsEye", withExtension: "html") return nil?
If so, you should check for the two things below:
Whether the file to be read is included in Copy Bundle Resources
Files to be included in the project are registered in TARGETS> Build Phases> Copy Bundle Resources.
Whether the file to be read exists in the project directory
Open the project directory in the Finder and check if the file you are trying to load actually exists.
Hope this helps!
Below code will help you.
func loadHtmlFile() {
if let fileurl = Bundle.main.url(forResource: "BullsEye", withExtension: "html") {
let request = URLRequest(url: fileurl!)
webView.loadRequest(request)
}
}
See - swiftdeveloperblog
Also if the code don't seem to work for you, make sure to open html file in any browser and check if it's a valid html file.
Apple's recommendation:
In apps that run in iOS 8 and later, use the WKWebView class instead of using UIWebView.
Thus, I have replaced my good old UIWebView with a shiny new WKWebView. But what I thought to be an easy exercise (simply swapping the classes and replacing the delegate methods) turned out to be a real mess.
The Problem
When I load an HTML string using
loadHTMLString(String, baseURL: URL?)
the web view loads and renders the pure HTML but it doesn't load any images or CSS files referenced inside the htmlString.
This happens only on a real device!
In Simultor all referenced resources are loaded correctly.
Example
I have defined a simple htmlString in my view controller class:
let imageName = "image.png"
let libraryURL: URL // The default Library URL
var htmlString: String {
return "<html> ... <img src=\"\(imageName)\" /> ... </html>"
// "..." represents more valid HTML code incl. header and body tags
}
The image is stored in the root Library folder so its URL is:
let imageURL = libraryURL.appendingPathComponent(imageName)
Now I load the htmlString into the web view:
webView.loadHTMLString(htmlString, baseURL: libraryURL)
and it doesn't load the image even though the baseURL is set correctly.
Ideas for a Solution
Maybe WKWebView has a problem with resolving relative paths so my first idea was to use absolute paths inside the HTML string instead.
→ ❌ Doesn't work.
Two answers to another SO post suggested that using
loadFileURL(URL, allowingReadAccessTo: URL)
instead of loadHTMLString(...) works in iOS 9+.
→ ✅ That works.
However, I cannot use solution 2 because my HTML files are encrypted and the decrypted files must not be stored on the disk.
Question
Is there any way to load local resources like images and styles using the WKWebView's
loadHTMLString(String, baseURL: URL?)
function? Or is still a bug in iOS 9+?
(I just cannot believe that Apple provides and recommends using a web view that cannot load any local web content from inside an HTML string?!)
Without taking a look at your actual project it's difficult to give some hundreed percent sure advices.
However:
class ViewController: UIViewController {
var webView = WKWebView()
override func viewDidLoad() {
super.viewDidLoad()
webView.translatesAutoresizingMaskIntoConstraints = false
let views = [
"webView" : webView
]
view.addSubview(webView)
var constraints = NSLayoutConstraint.constraintsWithVisualFormat("H:|[webView]|", options: [.AlignAllLeading, .AlignAllTrailing], metrics: nil, views: views)
constraints.appendContentsOf(NSLayoutConstraint.constraintsWithVisualFormat("V:|[webView]|", options: [.AlignAllTop, .AlignAllBottom], metrics: nil, views: views))
NSLayoutConstraint.activateConstraints(constraints)
let path = NSBundle.mainBundle().pathForResource("ios - WKWebView fails to load images and CSS using loadHTMLString(_, baseURL_) - Stack Overflow", ofType: "htm")
let url = NSURL(fileURLWithPath: path!)
webView.loadHTMLString(try! String(contentsOfURL: url), baseURL: url.URLByDeletingLastPathComponent)
// Do any additional setup after loading the view, typically from a nib.
}
override func didReceiveMemoryWarning() {
super.didReceiveMemoryWarning()
// Dispose of any resources that can be recreated.
}
}
I think the key point here is baseUrl parameter, you should setup it correctly. In my case i've used html's url without last path component - e.g. containing folder. This works fine on both device & simulator - check device snapshot. I've uploaded sample project to https://github.com/soxjke/WKWebViewTest so you can take a look (i've removed codesigning info from git)
So, to recap - method is working, functionality is working, just you do something wrong with it. To help you get what's wrong with your solutions, i'll add some suggestions:
1. Remember, that simulator filesystem is case-insensitive, device filesystem is case-sensitive. So if you have your filenames in html in lowercase - this won't work on device. 8fFsD.png != 8ffsd.png
2. Remember, that when copying resources, XCode ignores your folder structure. So if your html has <img src="./img/1.png"> and your XCOde project has folder structure like
test.htm
img/
1.png
2.png
After build it will be flattened, so test.htm and 1.png and 2.png will reside on same level
test.htm
1.png
2.png
I'm almost sure, after you verify these two assumptions, you'll get this method working.
I had this problem today, I've found the solution and potentially the cause:
loadHTMLString(String, baseURL: URL?)
This function doesn't allow the rendered HTML to access local media, as far as I'm aware, this is because it would be an injection risk, this could allow rendered HTML to access and manipulate your local file system. With a html string, that could come from anywhere or anyone.
loadFileURL(URL, allowingReadAccessTo: URL)
With this function, you point the WKWebview to the html file in your FileManager, and to the containing folder with 'allowingReadAccessTo'. Because the html is stored within the FileManager, it will allow the rendered HTML to access locally stored media.
If you don't have the html file stored locally for some reason(I assume you do), You could write the html sting into a .html file, then point to the URL of that file. However, this is just subverting Apple's protection, so do it at your own peril (don't do it).
This is just the solution that worked for me and my understanding of why we're having the problem to begin with.
Edit #1: Typo.
Edit #2: I've since found another nuance, When stating the 'allowingReadAccessTo:' URL, if the HTML itself needs to access things in parent folders (ie: .css, .js files), you need to specify the parent folder, not necessarily the location of the HTML itself, this will then implicitly allow access to the child folders as required also. For me, this problem was only apparent on a physical device, this didn't seem to have an effect whilst running in simulator, likely another discrepancy between how permissions work on simulator and a physical device.
Personally, I had to switch to using XWebView as the out-of-the-box behavior of WKWebView does not allow loading of local files. XWebView tricks it by loading up a local web server in the background and directing local traffic thru it. (XWebView is based on top of WKWebView)
Seems a bit overkill, but that is what I ended up having to do.
I've been experimenting with this as well, with similar restrictions, and the problem appears to be that paths aren't resolved unless baseURL references the application bundle. It doesn't work if you, for example, have something in the application's documents.
Edit: I have filed a radar for this rdar://29130863
Well you should be able to use local images and CSS files (and JavaScript files for that matter) with WKWebViews with the function that you have already found. My guess is that the problem is with your baseURL variable.
Update 7.5.2017:
I have completely updated the code from another SO answer of mine that used to be linked to my answer here. I have a working project for loadHTMLString() and .loadFileURL()
Try to create baseURL using:
let baseURL = URL(fileURLWithPath: "#path#")
instead of:
let baseURL = URL(string: "#path#")
The main difference is that the first method adds file:// prefix before the path.
You can base64 encode the images... I know that works. Not sure if it will be appropriate for your use case though.
Kind of funny, I just ran into this problem while doing the opposite - moving from base64 encoded to image files.
When I used UIWebview, I used baseURL as,
let baseUrl = NSURL(string: Bundle.main.path(forResource: "cms", ofType: "html")!)! as URL
webView.loadHTMLString(bodyPage, baseURL: baseUrl)
But for the WKWebView, I used baseURL as
let baseUrl = Bundle.main.bundleURL
webView.loadHTMLString(bodyPage, baseURL: baseUrl)
This works for me.
I know this is quite old already, but I ran into the exact same problem and it took me hours of trials and even to find this thread with the same problem (Xamarin Forms App)
My issue was: parsing remote HTML content into a string and also adding locally saved images (also downloaded dynamically, no resource of the app). On the simulator all works well, but on acutal device the local images are not showing (also no ? or anything indicating an error, just a blank frame). The Xamarin webview also offers the "BaseURL" option which didn't help, also not to use the BaseURL on the custom iOS wkWebView.
The only working solution as pointed out by Scott above, is to write the HTML into a file and then use the "LoadFileUrl" function and allow read access to the base directory. This also works with absolute file paths for images in the HTML (not only relative to the basedir, but of course somewhere within the basedir).
My custom webview renderer to load web and local content looks like this now:
protected override void OnElementPropertyChanged(object sender, PropertyChangedEventArgs e) {
base.OnElementPropertyChanged(sender, e);
NSUrl baseURL = new NSUrl(App.dirNews, true);
string viewFile = Path.Combine(App.dirNews, "view.html");
NSUrl fileURL = new NSUrl(viewFile, false);
switch (e.PropertyName) {
case "Url":
System.Console.WriteLine("--- Loading Web page ---");
System.Console.WriteLine("--- " + Element.Url + " ---");
NSUrlRequest myRequest = new NSUrlRequest(new NSUrl(Element.Url), NSUrlRequestCachePolicy.ReloadIgnoringLocalAndRemoteCacheData, 120);
Control.LoadRequest(myRequest);
break;
case "HTML":
System.Console.WriteLine("--- Showing HTTP content ---");
File.WriteAllText(viewFile, Element.HTML, System.Text.Encoding.UTF8);
Control.LoadFileUrl(fileURL, baseURL);
break;
}
}
I was able to reproduce a similar issue. WKWebView loads my images specially if they are located remotely, apart from my app server.
For servers that are not SSL-secured (http instead of https), you can set your info.plist as per below:
App Transport Security Settings
- Allow Arbitrary Loads in Web Content (Set to YES)
- Allow Arbitrary Loads (Set to YES)
The problem was actually in the server. The server application was either:
Changing the image src from "http://IP-or-domain/uploads/file.jpg" to "../../uploads/file.jpg"
- OR -
The image src was "http://localhost/uploads/file.jpg" or "http://127.0.0.1/uploads/file.jpg" instead of "http://YOUR-SERVER-IP-ADDRESS/uploads/file.jpg"
In these cases, the actual device wont be able to locate the image. This only works with iOS Simulator because the virtual device is the same as the server and development machine. It can read LOCALHOST and 127.0.0.1.
In my server, I was using a Rich Text Editor (TinyMCE) and it automatically removes the IP address after it detects that it's the same source.
WKWebView can load image or css file from NSTemporaryDirectory, so you can copy your files to NSTemporaryDirectory, and then load it. It works for me on iOS 14! see this issue. ios-wkwebview-loadhtmlstring-baseurl-fails-to-load-images-and-read-css
It took me a while to figure this out, but based on this answer I got it working:
https://stackoverflow.com/a/73519282/5868066
Try this:
let htmlPath = URL(fileURLWithPath: "")
let htmlDirectory = htmlPath.deletingLastPathComponent()
let htmlString = try! String(contentsOfFile: htmlPath.path, encoding: .utf8)
let baseURL = URL(fileURLWithPath: htmlDirectory)
let documentsDirectory = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask)[.zero]
webView.loadFileURL(htmlPath, allowingReadAccessTo: documentsDirectory)
webView.loadHTMLString(htmlString, baseURL: baseURL)
I am having trouble playing a local video on my computer. I used a library called Player which is quite straight forward, and in the example project, it's using a Vine video with supplying a link at the top, and it's working:
let videoUrl = NSURL(string: "https://v.cdn.vine.co/r/videos/AA3C120C521177175800441692160_38f2cbd1ffb.1.5.13763579289575020226.mp4")!
Thus, in ViewDidLoad, self.player.setUrl(videoUrl) works.
I tried to download the Vine video to my local. I saved it as aaa.mp4.
I dragged the mp4 file in xCode project.
I added the file in Copy Bundle Resources
Then I used;
let path = NSBundle.mainBundle().pathForResource("aaa", ofType:"mp4")!
let videoUrl = NSURL(string: path)!
viewDidLoad() {
// print(path)
// print(videoUrl)
self.player.setUrl(videoUrl)
}
The video doesn't get played, but
print(path) - gives me:
/Users/sentiasa/Library/Developer/CoreSimulator/Devices/67160785-1BDB-4046-BD58-A8C448938A4F/data/Containers/Bundle/Application/5456FF89-904F-4AE6-A90C-747B6A371745/Player.app/aaa.mp4
and print(videoUrl) - gives me:
/Users/sentiasa/Library/Developer/CoreSimulator/Devices/67160785-1BDB-4046-BD58-A8C448938A4F/data/Containers/Bundle/Appl ... /aaa.mp4
Please note that, if I give the path a filename that doesn't exists, it throws an error, thus I know the file is there (and exists) in my case.
What may be the problem? What am I missing? I don't receive any warnings or errors
Use
NSURL(fileURLWithPath: path)!
instead.
I'm trying to load a PDF into a UIWebView, but when using loadRequest, I'm getting the error unexpectedly found nil while unwrapping an Optional. My relevant code is below:
let url = NSURL(string: "http://www.urartuuniversity.com/content_images/pdf-sample.pdf")!
println(url.fileURL)
println("The URL is \(url.absoluteURL!)")
let request = NSURLRequest(URL: url)
webView.loadRequest(request)
The second line of code outputs false (unsurprisingly), but the third outputs the correct URL. webView is a connected UIWebView.
I've looked at a few examples of similar errors yet none seemed applicable, especially because the NSURL appears to be working due to the URL.absoluteURL! correctly outputting, as did numerous other similar commands.
I've also seen references to RFC 2396, but when looking at W3's documentation, my URL appears to be following these guidelines, but if it doesn't, then please tell me what the format is and how to change the URL (because I will have to literally change thousands more, and this PDF is merely an example PDF I found online).
When looking in the debug section, url is a NSURL and the place holding its value says the URL of the PDF, rather than a memory address, which could contribute partly to some of my problems.
Edit: To make my situation even weirder, because I'm using a universal app with a split-view and a table view, when I load an iPad, the PDF loads correctly, but the moment I go back to the master view and click on something, reloading the detail view, the fatal exception is found. If this made no sense, please tell me and I'll try to make it more comprehensible.
The problem is that you do not know what is nil. Add more logging, like this:
let url = NSURL(string: "http://www.urartuuniversity.com/content_images/pdf-sample.pdf")!
let request = NSURLRequest(URL: url)
println(url)
println(request)
println(webView)
webView.loadRequest(request)
In this way, by putting your app through its paces and trying to reproduce the crash, you will discover, just before the crash, exactly what is nil. I'm guessing it's the webView, but guessing is not programming — and the problem is that, so far, you are just guessing. Don't guess. You have a debugger! Debug!!!
One of the modules of my app is a web site. That web site contains primarily an SVG drawing, with custom shaped buttons (using Raphael.js library) to access other drawings (other html page with svg drawings).
If the device is on iOS 7, I use a UIWebView and everything works fine.
For iOS 8 devices, I use a WKWebView. I had some issues, some of them resolved by this post. I can see my web site on those simulators (iPhone 5 / iOS 8.0 (12A365) & iPhone 5s / iOS 8.0), but I can't see it on my iPod Touch (5th gen, running iOS 8.0.2). It shows a blank screen.
I don't know what to look for. Any idea?
EDIT
After following #Dan Fabulich's answer (here), I now get a forever-loading webview, that never finishes loading up. His answer tells us that there is a bug with WKWebView when loading html from a string. His answer is to copy the html content into a new subfolder and then call loadRequest from that URL.
Unfortunately, I'm still stuck with a non-working webview. Any clue? What would be a reason for a webview to never finish loading up content?
i had some problem but i solved problem with configuration options. here is my my code.
var a = dic["adi"]?.asString()
var path = NSBundle.mainBundle().pathForResource(a, ofType: "htm" )
var url = NSURL(fileURLWithPath:path!)
var request = NSURLRequest(URL:url!)
var theConfiguration = WKWebViewConfiguration()
theWebView = WKWebView(frame:self.view.frame, configuration: theConfiguration)
var error:NSError?
let text2 = String(contentsOfFile: path!, encoding:NSUTF8StringEncoding, error: &error)
if let theError = error
{
print("\(theError.localizedDescription)")
}
theWebView!.loadHTMLString(text2!, baseURL: nil)
self.view.addSubview(theWebView!)
hope this helps.