How can I show an alert only if the user visits a specific website in my app?

Question

How can I show the user an alert if they visit https://google.com, https://duckduckgo.com, https://bing.com or https://yandex.ru, but don't show anything when they visit any other website?

I have tried this, but no success. (This is just a part of my code)

var isSearchEngine="NO"

if urlString!.contains("https://google.com") {
        var isSearchEngine="YES"
    } else {
        var isSearchEngine="NO"
    }
    
    if urlString!.contains("https://duckduckgo.com") {
        var isSearchEngine="YES"
    } else {
        var isSearchEngine="NO"
    }
    
    if urlString!.contains("https://yandex.ru") {
        var isSearchEngine="YES"
    } else {
        var isSearchEngine="NO"
    }
    
    if urlString!.contains("https://bing.com") {
        var isSearchEngine="YES"
    } else {
        var isSearchEngine="NO"
    }
    
    if isHub=="YES" {
        Debug.log("Visited search engine website.")
        let alert = UIAlertController(title: "Search Engine Detected", message: "The website you visited is a search engine.", preferredStyle: .alert)

        alert.addAction(UIAlertAction(title: "OK", style: .cancel, handler: nil))

        self.present(alert, animated: true)
    } else {
        Debug.log("Didn't visit a Search engine website.")
        let alert = UIAlertController(title: "No search engine", message: "The website you visited isn't a search engine.", preferredStyle: .alert)

        alert.addAction(UIAlertAction(title: "OK", style: .cancel, handler: nil))

        self.present(alert, animated: true)
    }

Every time I run my app with this code, I always get the "No Search Engine" alert, no matter what website I visit. Always "No search engine". Can anyone help me? Many thanks in advance!

Answer 1

Your code does not make sense as written. It executes a series of if/else expressions one after the other. If the URL contains "https://google.com" for example, the first if/else statement would set isSearchEngine to true, and then the very next if/else statement would set it back to false.

Rewrite it. Something like this would work:

var isSearchEngine = false

if let notNilURLString = urlString {
    let searchEngineURLs = [
       "https://google.com", 
       "https://yandex.ru", 
       "https://duckduckgo.com"] // And so on
    for searchEngineURL in searchEngineURLs {
        if notNilURLString.contains(searchEngineURL)
           isSearchEngine = true
        }
    }
}

Second problem: After trying to set isSearchEngine = true when you detect the URL for a search engine, the rest of your code goes on to check if a string isHub=="YES", completely ignoring the value of isSearchEngine.

Third point: Use the Bool type for true/false, not strings containing "YES" and "NO".