How to load a string from a website URL

Swift version: 5.4

Paul Hudson @twostraws May 28th 2019

It takes just a few lines of Swift code to load the contents of a website URL, but there are three things you need to be careful with:

Creating a URL might fail if you pass a bad site, so you need to unwrap its optional return value.
Loading a URL's contents might fail because the site might be down (for example), so it might throw an error. This means you need to wrap the call into a do/catch block.
Accessing network data is slow, so you really want to do this on a background thread.

Here's the code:

if let url = URL(string: "https://www.hackingwithswift.com") {
    do {
        let contents = try String(contentsOf: url)
        print(contents)
    } catch {
        // contents could not be loaded
    }
} else {
    // the URL was bad!
}

If you want to run that on a background thread (and you really ought to!) you should either use GCD's async() or performSelector(inBackground:).