How To initialise a string using contentsOfURL and update a UILabel's text in Swift

Question

I'm trying to read data from a webpage and I'm using the NSString initialiser - init(contentsOfURL since there's only one sentence on that page that I need to display in a label.

if var optUrl = NSURL(string: "www.example.com/examplepage.php"){
        if let optStr = NSString(contentsOfURL: optUrl, encoding: NSUTF8StringEncoding, error: nil){
            println(optStr)
            songLabel.text = optStr
        }

    }

When I run the code in the emulator in Xcode, the println does print the sentence, but it won't show in the label... If I change the code to songLabel.text = "Now playing: \(optStr)", I get to see Now playing: but not the value of optStr which is shown by the println.

Is there something I did wrong?

try adding http:// to the optUrl http://stackoverflow.com/questions/10106087/nscocoaerrordomain-code-256 — Daniel Galasko, Feb 10 '15 at 13:11
That being said its not the best practice to rely on NSString to download content for you, a better approach would be to download your files using NSURLSession and parse them from there — Daniel Galasko, Feb 10 '15 at 13:11

Daniel Galasko · Answer 1 · 2015-02-10T13:23:28.853

0

Conclusion

Turns out that everything was working, the string was preceded by a newline character and since the labels number of lines was 0 the text wasn't visible. Breakpoints are always your friend.

Irrelevant

Looks like you need to add http://

This worked in a playground for me for a php file

if var optUrl = NSURL(string: "http://php.net/manual/en/function.file.php") {
    println(optUrl)
    var error: NSError? = nil
    if let optStr = NSString(contentsOfURL: optUrl, encoding: NSUTF8StringEncoding, error: &error) {
        println(optStr)
    }
    print(error)
}

Edit

Its also possible that perhaps your string is empty seeing as you stated that setting "Now playing: (optStr)" results in "Now playing:"

Validate your contents in a playground, but you should at least be able to check

countElements(optStr) > 0

edited Feb 10 '15 at 13:23

answered Feb 10 '15 at 13:12

Daniel Galasko

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The `println` does indeed work, but I have to put the `optStr` into a label, which doens't work – m1ch14l Feb 10 '15 at 13:14
@m1ch14l well you can always place a breakpoint on the line and confirm, alternatively you can place the set text into a NSOperationQueue.mainQueue().addOperationWithBlock { () -> Void in //set text here } – Daniel Galasko Feb 10 '15 at 13:18
@m1ch14l I updated my answer, its possible your php is actually empty – Daniel Galasko Feb 10 '15 at 13:24
1

Got it working, I placed a breakpoint at `songLabel.text = optStr` and noticed that `optStr` contained a `\n` at the beginning of the string. I changed the lines of the label to 2 and now I can see the string... I feel stupid and dumb :p Thanks for the help ;) – m1ch14l Feb 10 '15 at 13:24
@m1ch14l haha awesome! – Daniel Galasko Feb 10 '15 at 13:24

How To initialise a string using contentsOfURL and update a UILabel's text in Swift

1 Answers1

Conclusion

Irrelevant

Edit