I have the following Swift extension on NSURL
public extension NSURL {
func getQueryItemValueForKey(key: String) -> String? {
guard let components = NSURLComponents(URL: self, resolvingAgainstBaseURL: false) else {
return nil
}
guard let queryItems = components.queryItems else { return nil }
return queryItems.filter {
$0.name == key
}.first?.value
}
}
I am writing unit tests for it but I am unable to get 100% code coverage as I don't seem to be able to get NSURLComponents(URL: self, resolvingAgainstBaseURL: false) to return nil. From what I understand, this requires a malformed URL but I am struggling to create one.
I have tried:
let url = NSURL(string: "")
let url = NSURL(string: "http://www.example")
let url = NSURL(string: "http://www.exam ple.com")
let url = NSURL(string: "http://www.example.com/?param1=äëīòú")
And some others that I lost track of. I know this is probably something blatantly obvious but i'm lost at the moment. So, how do I create a malformed URL in Swift?
As found in my research, you can produce a url that is malformed for NSURLComponents but not for NSURL by using negative port number (probably there are more cases but not sure):
let example = "http://example.com:-80/"
let url = NSURL(string: example)
print("url:\(url)") //prints out url:Optional(http://example.com:-80/)
if let url = url {
let comps = NSURLComponents(URL: url, resolvingAgainstBaseURL: false)
print("comps:\(comps)") //prints out comps:nil
}
Related
I am trying to show an image into my table cell view from an API. But it has given a partial link there, as a result, I am getting NSURL connection error code -1002.
Here is my API link: https://api.opendota.com/api/heroStats
I am trying to parse "icon" among them:
"img": "/apps/dota2/images/heroes/antimage_full.png?",
"icon": "/apps/dota2/images/heroes/antimage_icon.png",
My code:
// Generating imageview
if let imageURL = URL(string: heroes[indexPath.row].icon){
print (imageURL)
DispatchQueue.global().async {
let data = try? Data (contentsOf: imageURL)
if let data = data {
let image = UIImage(data: data)
DispatchQueue.main.async {
cell.charIcon.image = image
} //end of 2nd dispatch
}//end of if
}//end of 1st dispatch
}// end of imageURL
How can I solve this problem? Any easy way for swift 4?
You can get the url components of your api link and use your icon "partial link" to set the path property of the URL components. After that you just need to get the resulting url of the url components:
let apiLink = "https://api.opendota.com/api/heroStats"
let apiURL = URL(string: apiLink)!
if var urlComponents = URLComponents(url: apiURL, resolvingAgainstBaseURL: false) {
let iconString = "/apps/dota2/images/heroes/antimage_icon.png"
urlComponents.path = iconString
if let iconURL = urlComponents.url {
print(iconURL.absoluteString)
}
}
This will print
https://api.opendota.com/apps/dota2/images/heroes/antimage_icon.png
You can create a custom method to return a new URL based on the new path string as follow:
extension URL {
var urlComponents: URLComponents? {
return URLComponents(url: self, resolvingAgainstBaseURL: false)
}
func bySettingNew(path: String) -> URL? {
guard var urlComponents = urlComponents else { return nil }
urlComponents.path = path
return urlComponents.url
}
}
let apiLink = "https://api.opendota.com/api/heroStats"
let apiURL = URL(string: apiLink)!
let iconString = "/apps/dota2/images/heroes/antimage_icon.png"
if let iconURL = apiURL.bySettingNew(path: iconString) {
print(iconURL.absoluteString)
}
You can also add this helper to your project to make it easier for you to download an image asynchronously into your image view:
extension UIImageView {
func downloaded(from url: URL, contentMode mode: UIView.ContentMode = .scaleAspectFit) {
URLSession.shared.dataTask(with: url) { data, response, error in
guard
let httpURLResponse = response as? HTTPURLResponse, httpURLResponse.statusCode == 200,
let mimeType = response?.mimeType, mimeType.hasPrefix("image"),
let data = data, error == nil,
let image = UIImage(data: data)
else { return }
DispatchQueue.main.async() { [weak self] in
self?.contentMode = mode
self?.image = image
}
}.resume()
}
}
if let imageURL = apiURL.bySettingNew(path: heroes[indexPath.row].icon) {
cell.charIcon.downloaded(from: imageURL)
}
Essentially I am parsing JSON data and assigning it to a variable called addressPressNow I then have the following function that executes when a user taps on a UILabel:
The goal is to have Apple Maps open provided the variable value it contains.
Because I am assigning an address to a variable it will contain spaces
ex: 3981 Test Drive Cupertino CA 95014
NOTE: The value of the variable is being passed correctly because when I do print(addressPressNow) in func tapFunction it prints correctly.
#objc
func tapFunction(sender:UITapGestureRecognizer) {
let targetURL = NSURL(string: "http://maps.apple.com/?q=" + addressPressNow)!
UIApplication.shared.openURL(targetURL as URL)
}
The issue is I am having trouble applying the variable to the string URL with the following error:
Thread 1: Fatal error: Unexpectedly found nil while unwrapping an
Optional value
The following is how I am assigning the value to the variable:
struct FacilityInfo: Decodable {
let address: String
class infoViewController: UIViewController {
var addressPressNow : String = ""
override func viewDidLoad() {
super.viewDidLoad()
let tap = UITapGestureRecognizer(target: self, action: #selector(infoViewController.tapFunction))
addressInfo.isUserInteractionEnabled = true
addressInfo.addGestureRecognizer(tap)
let url = URL(string: "https://test/test/example”)!
let task = URLSession.shared.dataTask(with: url) { data, response, error in
// ensure there is no error for this HTTP response
guard error == nil else {
print ("error: \(error!)")
return
}
// ensure there is data returned from this HTTP response
guard let data = data else {
print("No data")
return
}
// Parse JSON into array of Car struct using JSONDecoder
guard let cars = try? JSONDecoder().decode([FacilityInfo].self, from: data), let secondCar = cars.first
else {
print("Error: Couldn't decode data into cars array")
return
}
DispatchQueue.main.async {
self.addressPressNow = secondCar.facility_address
}
}
"I am assigning an address to a variable it will contain spaces"
If the address contains spaces then creating NSURL with the string will crash. You can use addingPercentEncoding to solve the problem
if let encodedAddress = addressPressNow.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed) {
let targetURL = NSURL(string: "http://maps.apple.com/?q=" + encodedAddress)!
UIApplication.shared.openURL(targetURL as URL)
}
And don't use NSURL and force unwrapping. Update it like this
if let encodedAddress = addressPressNow.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed),
let targetURL = URL(string: "http://maps.apple.com/?q=" + encodedAddress) {
UIApplication.shared.openURL(targetURL)
}
As suggested by matt use URLComponents
let addressPressNow = "3981 Test Drive Cupertino CA 95014"
var components = URLComponents(string: "http://maps.apple.com")
components?.queryItems = [URLQueryItem(name: "q", value: addressPressNow)]
print(components?.url)//http://maps.apple.com?q=3981%20Test%20Drive%20Cupertino%20CA%2095014
if let targetURL = components?.url {
UIApplication.shared.open(targetURL, options: [:], completionHandler: nil)
}
You are saying
NSURL(string: "http://maps.apple.com/?q=" + addressPressNow)!
Notice the exclamation mark at the end. That means "if there's a problem, crash me". You can hardly complain if you do in fact crash; that is what you asked to do.
Basically, never use NSURL(string:) if you can avoid it. To form a valid URL, build it up using URLComponents. And form it out of valid components. (It is impossible to say whether facility_address is a valid URL query, because you have not shown what it is.)
Example:
var comp = URLComponents()
comp.scheme = "https"
comp.host = "maps.apple.com"
comp.queryItems = [URLQueryItem(name: "q", value: "1 Infinite Loop, Cupertino, CA")]
if let url = comp.url {
print(url) // https://maps.apple.com?q=1%20Infinite%20Loop,%20Cupertino,%20CA
}
That gives us a valid URL that actually works.
I have a query on a Cloud CKRecord, which checks to see if a documents exists (i.e. has been uploaded as an CKAsset) and if not checks if a URL exists (i.e. has been uploaded as a String). All works well if either exist on their own for a given record, however if both exist when clicking on the link nothing happens.
I feel it is something to do with the if and else if statements -
if filename1 != nil {
let asset1 = record.object(forKey: "courseDocument1") as? CKAsset
let filename = record.object(forKey: "courseDocument1Filename") as! String
let path = (NSTemporaryDirectory() as NSString).appendingPathComponent(filename)
let doc1Data : NSData? = NSData(contentsOf:(asset1?.fileURL)!)
do {
try doc1Data!.write(to: URL(fileURLWithPath: path), options: .atomic)
let url = URL(fileURLWithPath: path)
let urlRequest = URLRequest(url: url)
self.courseDoc1WebView?.loadRequest(urlRequest)
self.venueDocButton1.setTitle(cseDocument1,for: [])
self.venueDocButton1.isHidden = false
self.courseDocumentLabel.isHidden = false
} catch {
print(error)
}
} else if cseDocument1URL != nil && filename1 == nil {
let url1 = URL (string: cseDocument1URL!)
let request1 = URLRequest(url: url1! as URL );
self.courseDoc2WebView.loadRequest(request1 as URLRequest);
self.venueDocButton1.setTitle(cseDocument1,for: [])
self.venueDocButton1.isHidden = false
self.courseDocumentLabel.isHidden = false
} else {
print("No Document Found")
}
Any thoughts?
This turned out to be a simple typo rather than logic -
self.courseDoc2WebView.loadRequest(request1 as URLRequest);
which should actually be -
self.courseDoc1WebView.loadRequest(request1 as URLRequest);
This was solved by printing responses and using the debugger - thanks Phillip Mills
Duncan C, you make a good point too - thank-you.
let imgURL:NSURL = NSURL(string: "\(ImageName)")!
at the above line,i'm getting fatal error
fatal error: unexpectedly found nil while unwrapping an Optional value
(lldb)
Code :
let ImageName = obj["image"] as! String
let imgURL:NSURL = NSURL(string: "\(ImageName)")!
let request: NSURLRequest = NSURLRequest(URL: imgURL)
let session = NSURLSession.sharedSession()
let Imgtask = session.dataTaskWithRequest(request){
(data, response, error) -> Void in
if (error == nil && data != nil)
{
func display_image()
{
pointAnnoation.DisplayImage = UIImage(data: data!)
}
dispatch_async(dispatch_get_main_queue(), display_image)
}
}
Imgtask.resume()
From the above code im trying to store my image from database in annotation
if i printed the 'ImageName' it returns the name from the database correctly, but unable to retain the image
it resulting in the error while running.
You say that
if i printed the 'ImageName' it returns the name from the database correctly
Then that must mean that the ImageName is not valid for a URL
If you look at the description of NSURL(string:) it says:
The URL string with which to initialize the NSURL object. This URL string must conform to URL format as described in RFC 2396, and must not be nil. This method parses URLString according to RFCs 1738 and 1808.
So the question is...how does ImageName look? And can you create a URL from it?
Apart from that, it is always a good idea to use ? instead of ! as #PhillipMills says
Update: I can see that you have posted an example of your URL now. If I do this in a playground:
let url = NSURL(string: " goo.gl/pBmA0d")
I get nil in return, so it would seem that short URLs and NSURLaren't the best of friends.
Update 2: hmm, guess I spoke to quickly, if you look at the above you can see that I have a space before the goo.gl part, if I change that to:
let url = NSURL(string: "goo.gl/pBmA0d")
it actually works, I get a NSURL object.
But another thing I stumbled upon in your code. You declare ImageName as a String here:
let ImageName = obj["image"] as! String
So you don't have to wrap it in \() later on
let imgURL:NSURL = NSURL(string: "\(ImageName)")!
You could simply say:
let imageURL = NSURL(string: ImageName)
And then...as others has said, it is always a good idea to use ? instead of !
So you could write:
if let imageName = obj["image"] as? String,
let imageURL = NSURL(string: imageName) {
//we're in business :-)
}
and be safe and sound
Try to use guard or if let for helping yourself.
let ImageName = obj["image"] as! String
if let imgURL = NSURL(string: ImageName) {
let request: NSURLRequest = NSURLRequest(URL: imgURL)
let session = NSURLSession.sharedSession()
let Imgtask = session.dataTaskWithRequest(request){ (data, response, error) -> Void in
if (error == nil && data != nil)
{
// What's that func??
func display_image()
{
pointAnnoation.DisplayImage = UIImage(data: data!)
}
dispatch_async(dispatch_get_main_queue(), display_image)
}
}
}
Imgtask.resume()
Don't make force unwrap...use if let to avoid crash ...
if let img = obj["image"] as? String,
imgURL = NSURL(string: img) {
// ... continue with your code ...
}
Please try the following code:
//ImageName is a String type.
guard let ImageName = obj["image"] as? String , let imgURL = NSURL(string: ImageName) else{
return
}
let request: NSURLRequest = NSURLRequest(URL:imgURL)
let session = NSURLSession.sharedSession()
let Imgtask = session.dataTaskWithRequest(request){
(data, response, error) -> Void in
if (error == nil && data != nil)
{
func display_image()
{
pointAnnoation.DisplayImage = UIImage(data: data!)
}
dispatch_async(dispatch_get_main_queue(), display_image)
}
Imgtask.resume()
This is my NSURL
let url = NSURL(string: "tel://\(phoneCall)")
It is always nil, although the phoneCall is a valid mobile number string, and I am testing on a real iPhone.
I tried
let url = NSURL(string: "tel:\(phoneCall)")
but it's still nil.
let phoneCall = "tel://9000002143";
let url:NSURL = NSURL(string:phoneCall);
//OR
var url:NSURL = NSURL(string: "tel://9000002143")
if phoneCall == nil || phoneCall.isEmpty
{
print("phoneCall is empty or nil.")
}
else
{
UIApplication.sharedApplication().openURL(url);
}
Where this phoneCall is set?
I had a similar issue with a optional type. This code illustrate the problem:
let user = row.value
let phone = user?.phone
let url = NSURL(string: "tel://\(phone)")
UIApplication.sharedApplication().openURL(url!)
In this case, the value of urlString variable is "tel://Optional(\"11XXXXXXXXX\")", because the user variable can be nil.
You have to ensure that the user is not nil first, something like:
guard let user = row.value else {
return
}
let phone = user.phone
let urlString = "tel://\(phone)"
let url = NSURL(string: urlString)
UIApplication.sharedApplication().openURL(url!)