I have a function called downloadImage. I'm trying to get image data and set an imageView. But it prints "no data".

image link: http://commons.wikimedia.org/wiki/Special:FilePath/Flag of Montenegro.svg

Here is my code:

func downloadImage() {
    
    let uri = "Special:FilePath/Flag of Montenegro.svg"
    let baseURL = URL(string: "http://commons.wikimedia.org/wiki/")!
    let imageURL = URL(string: uri, relativeTo: baseURL)!
    if let data = try? Data(contentsOf: imageURL){
        if let image = UIImage(data: data){
            DispatchQueue.main.async {
                self.flagImageView.image = image
            }
        }
        else{
            print("image cannot be taken")
        }
    }else{
        print("no data")
    }
}

Here is console output:

2022-09-03 21:21:56.426579 0300 CountryBook[5242:197393] nil host used in call to 
allowsSpecificHTTPSCertificateForHost
2022-09-03 21:21:56.426913 0300 CountryBook[5242:197393] nil host used in call to allowsAnyHTTPSCertificateForHost:
2022-09-03 21:21:56.427580 0300 CountryBook[5242:197905] NSURLConnection finished with error - code -1002
no data

Note:

I Allowed Arbitrary Loads from info.plist by marking it as YES.

CodePudding user response：

Assuming you did allow the usage of http corectly. There is more going on here:

• The link you provided redirects to https://upload.wikimedia.org/wikipedia/commons/6/64/Flag_of_Montenegro.svg. Data(contentsOf: is not for this purpose. It is best suited for loading data from a bundle file url and not complex redirecting or cookies or header..... . Use a proper URLSesssion.

• Even if you get your data it will not work this way. UIImage doesn´t support SVG format. See this SO question for more info

Remarks:

Just use https. It´s de facto standard. And your link to wikipedia would support it. Falling back to http should be the last resort while developing and never in production.

CodePudding user response：

this is actually due to the fact that apple no longer allows http urls by default, it wants them to be https

When using a https url, you also shouldn't need to allowArbitraryLoads

From what I suspect though, wikipedia is https, so I think you can just change your url to have https like so: https://commons.wikimedia.org/wiki/Special:FilePath/Flag of Montenegro.svg