Issue with turning Wikipedia url string into URL in Swift - swift

The URL I am making is valid and will return the desired JSON when testing on Chrome, but fails in my project.
func createWikipediaURL(place: String) -> URL? {
let _place = place.replacingOccurrences(of: " ", with: "%20")
let urlStr =
"https://en.wikipedia.org/w/api.php?format=json&action=query&prop=extracts|pageimages&exintro&explaintext&generator=search&gsrsearch=intitle:\(_place)&gsrlimit=1&redirects=1"
if let url = URL(string:urlStr) {
return url
} else {
return nil
}
}
With the parameter "Malibu Beach" the function will create the proper URL, https://en.wikipedia.org/w/api.php?format=json&action=query&prop=extracts|pageimages&exintro&explaintext&generator=search&gsrsearch=intitle:Malibu%20Beach&gsrlimit=1&redirects=1, but will also result in no URL being returned because this string cannot be casted into a URL. Any suggestions on how to make the string into a URL?

The issue is with the | character in urlStr. I would suggest using Strings addingPercentEncoding method to make the string url safe. Doing so will mean that you won't need to manually replace spaces for place too.
func createWikipediaURL(place: String) -> URL? {
let urlStr = "https://en.wikipedia.org/w/api.php?format=json&action=query&prop=extracts|pageimages&exintro&explaintext&generator=search&gsrsearch=intitle:\(place)&gsrlimit=1&redirects=1"
// Replaces special characters with their percent encoded counter-parts.
guard let escapedUrlStr = urlStr.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed) else { return nil }
// There's no need for an if statement; URL can be returned as-is.
return URL(string:escapedUrlStr)
}

Related

Prepare String for URL cast in Swift

I have a text Area, the content of which will later be used to create a URL. How can I validate that the url - cast doesn't throw an error? Is there a function that can do that? For example remove all invalid Characters. I cast the String in the following way, but if the user inputs a newline the cast doesn't work:let url: URL = URL(string: urlPath)!
Use optional binding (https://docs.swift.org/swift-book/LanguageGuide/TheBasics.html):
var str = "somescheme://somedata"
if let url = URL(string: str) {
// handle url
} else {
// handle error
}
If you want to strip whitespaces and new line characters, use:
str.trimmingCharacters(in: .whitespacesAndNewlines)

URL constructor doesn't work with some characters

I'm trying to call a php-script from my app using URLRequest.
The Url path is generated in the String-Variable query and for the request I convert it like this
guard let url = URL(string: query) else {
print("error")
return
}
usually it works, but when the request contains characters like ä, ö, ü, ß the error is triggered. How can I make it work?
The URL(string:) initializer doesn't take care of encoding the String to be a valid URL String, it assumes that the String is already encoded to only contain characters that are valid in a URL. Hence, you have to do the encoding if your String contains non-valid URL characters. You can achieve this by calling String.addingPercentEncoding(withAllowedCharacters:).
let unencodedUrlString = "áűáeqw"
guard let encodedUrlString = unencodedUrlString.addingPercentEncoding(withAllowedCharacters: .urlQueryAllowed), let url = URL(string: encodedUrlString) else { return }
You can change the CharacterSet depending on what part of your URL contains the characters that need encoding, I just used urlQueryAllowed for presentation purposes.
Split your URL in two separate parts:
let baseURLString = "https://www.example.com"
let pathComponent = "áűáeqw"
let fullURL = URL(string: baseURLString)?.appendingPathComponent(pathComponent)

Could not cast value of type Kanna.libxmlHTMLNode to 'NSString

I am trying to scrape some data from a website, and since there is no API, I am trying to use ALAMOFIRE + KANNA
I can print my results in the console, but as soon as I try to convert in String to use it in my app it says:
Could not cast value of type 'Kanna.libxmlHTMLNode' (0x10887d210) to 'NSString' (0x108efc0d0).
Why couldn't I cast the data in String using as! String
my code
var competitions:[String] = []
// Grabs the HTML
func scrapeData() -> Void {
Alamofire.request("MYWEBSITE.com").responseString { response in
print("\(response.result.isSuccess)")
if let html = response.result.value {
self.parseHTML(html: html)
}
}
}
func parseHTML(html: String) -> Void {
if let doc = try? Kanna.HTML(html: html, encoding: String.Encoding.utf8) {
do {
// Search for nodes by XPATH selector
for competition in doc.xpath("""
//*[#id="page_teams_1_block_teams_index_club_teams_2"]/ul
""") {
let competitionName = competition.at_xpath("li/div/a")
print(competitionName?.content ?? "N/A")
competitions.append(competition as! String)
competition is a libxmlHTMLNode, not a String. You can't simply force-cast one type of object to another, unrelated type.
Most likely you want to append competitionName, not competition to your string array. But you need to convert it to a String using its text property:
competitions.append(competitionName?.text ?? "N/A")

Reading URLS in JSON api with swift

For work we have a third party company which supply a JSON api for some functionality. The JSON contains urls which I try to map in my code with URL(string: ...) but this fails on some urls which have spaces.
For example:
var str = "https://google.com/article/test test.html"
let url = URL(string: str) //nil
Should I ask the third party to encode their URLs ?
Is this normal or should I try to add encoding myself?
Encoding myself is hard I think because the path should be encoded different from the query and the host shouldn't be encoded etc.
Or am I overthinking this?
If the URL contains spaces in its path, escape the characters with addingPercentEncoding(withAllowedCharacters passing the urlPathAllowed character set:
let str = "https://google.com/article/test test.html"
if let escapedString = str.addingPercentEncoding(withAllowedCharacters: CharacterSet.urlPathAllowed),
let url = URL(string:escapedString) {
print(url)
} else {
print("url \(str) could not be encoded")
}
What I would do if I were you, is to split the string up on the space, try converting each of the elements to a url, and when that works save it in your variable.
var str = "https://google.com/article/test test.html"
var url: URL? = nil
for urlString in str.components(separatedBy: .whitespacesAndNewlines) {
let url = URL(string: urlString)
if url != nil {
break
}
}
// url might be nil here, so test for value before using it
If each URL that you get from the API is in the format in your example, you can instead just grab the first element after spitting the string.
var str = "https://google.com/article/test test.html"
if let urlString = str.components(separatedBy: .whitespacesAndNewlines).first {
let url = URL(string: urlString)
}
// url might be nil here, so test for value before using it

AppleWatch Messages URL works hard coded but not with variables

TLDR When I hard code phone numbers into a URL it opens in watch messages correctly, but when I use a variable string with the numbers typed in exactly the same way inside of it, it doesn't.
Example:
NSURL(string: "sms:/open?addresses=8888888888,9999999999,3333333333&body=Test")
Above code works but below code doesn't:
let hardCode = "8888888888,9999999999,3333333333"
NSURL(string: "sms:/open?addresses=\(hardCode)&body=Test")
FULL DETAILS:
I am making a URL from variables to open messages on the Apple Watch with pre-filled contents. I am getting the phone numbers from the contact book and storing them in an array. They are provided in this format:
(###) ###-#### but need to be ##########
I tested the code by hard-coding phone numbers into the URL and it works properly with all contacts and completed body:
if let urlSafeBody = urlSafeBody, url = NSURL(string: "sms:/open?addresses=8888888888,9999999999,3333333333&body=\(urlSafeBody)") {
print("FINAL URL: \(url)")
WKExtension.sharedExtension().openSystemURL(url)
}
But when I build the phone number values programmatically it does not work:
//holds phone numbers without special chars
var tempArray: [String] = []
//if I can access the unformatted numbers
if let recips = saveData["recips"] as? [String] {
//for each number provided
recips.forEach { (person: String) in
//remove all non-numerical digits
//person is now (###) ###-####
let newPerson = person.digitsOnly()
//newPerson is ##########
print(person)
print("->\(newPerson)")
//add formatted number to tempArray
tempArray.append(newPerson)
}
}
//combine all numbers with "," between as a string
let recipString = tempArray.joinWithSeparator(",")
//recipString contains ##########,##########,##########...
extension String {
func digitsOnly() -> String{
let stringArray = self.componentsSeparatedByCharactersInSet(
NSCharacterSet.decimalDigitCharacterSet().invertedSet)
let newString = stringArray.joinWithSeparator("")
return newString
}
}
I then add the "recipString" variable to the NSURL in the below code:
let messageBody = "test"
let urlSafeBody = messageBody.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLHostAllowedCharacterSet())
if let urlSafeBody = urlSafeBody, url = NSURL(string: "sms:/open?addresses=\(recipString)&body=\(urlSafeBody)") {
print("FINAL URL: \(url)")
WKExtension.sharedExtension().openSystemURL(url)
}
The FINAL URL print shows the correct string, but the messages app does not open properly, and shows quick reply menu instead of composed message window. It matches the functioning hard coded number version exactly, but behaves differently.
Totally lost, hope someone can help!
UPDATE 1
Here are the debug prints for both versions of the URL:
Manually declared (not created from recipString but actually declared in the URL string explicitly):
This version works
FINAL URL: sms:/open?addresses=0000000000,1111111111,2222222222,3333333333,4444444444&body=test
Variable created (using recipString):
This version doesn't
FINAL URL: sms:/open?addresses=0000000000,1111111111,2222222222,3333333333,4444444444&body=test
I have also tried applying url encoding to the "recipString" variable by using the below if let:
if let urlSafeRecip = recipString.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLQueryAllowedCharacterSet()) {
if let urlSafeBody = urlSafeBody, url = NSURL(string: "sms:/open?addresses=\(urlSafeRecip)&body=\(urlSafeBody)") {
print("FINAL URL: \(url)")
WKExtension.sharedExtension().openSystemURL(url)
}
}
UPDATE 2
I tested to see if the hardcode version of numbers matches the recipString exactly via this code:
let hardCode = "0000000000,1111111111,2222222222,3333333333,4444444444"
let isEqual = (hardCode == recipString)
if isEqual {
print("hardCode matches recipString")
}
else {
print("hardCode does not match recipString")
}
Debug prints:
hardCode matches recipString
UPDATE 3
I have confirmed that:
When a URL is made with hard coded numbers vs. numbers that I make from variables, checking == between them returns true.
In every test I can do between the two version of the url, it matches.
NOTES AFTER CORRECT ANSWER FOUND:
This type of URL formatting will ONLY work with multiple addresses in the URL. If you do not have multiple addresses you will need to do the following, which is undocumented but none-the-less works. I found this by bashing my face on the keyboard for hours, so if it helps you an upvote is deserved :)
follow the answer marked below, and then use this type of logic check before making the URL in the doItButton() function he mentioned:
func setupAndSendMsg(saveData: NSDictionary) {
if let urlSafeBody = createBody(saveData) {
let theNumbers = createNumbers(saveData).componentsSeparatedByString(",")
print(theNumbers.count-1)
if theNumbers.count-1 > 0 {
if let url = NSURL(string: "sms:/open?addresses=\(createNumbers(saveData))&body=\(urlSafeBody)") {
print(url)
WKExtension.sharedExtension().openSystemURL(url)
}
} else {
if let url = NSURL(string: "sms:/open?address=\(createNumbers(saveData)),&body=\(urlSafeBody)") {
print(url)
WKExtension.sharedExtension().openSystemURL(url)
}
}
}
}
My guess is that it is not the acctual openSystemUrl call that is the problem. I believe there must be something with the code that is building the number string programmatically.
The code bellow is a simplified version of all the code you have posted. I have confirmed that it is working on my Apple Watch. It opens the Messages app with pre-populated numbers & body text.
Take one more look at your code and see if there is something your missing. If you can't find anything, just delete the code and re-write it, probably will be faster then spotting the weird issue.
Once again the code bellow is confirmed working as expected, so you should be able to get it to work. (or just copy & paste my code) :)
class InterfaceController: WKInterfaceController {
#IBAction func doItButton() {
if let urlSafeBody = createBody() {
if let url = NSURL(string: "sms:/open?addresses=\(createNumbers())&body=\(urlSafeBody)") {
print(url)
WKExtension.sharedExtension().openSystemURL(url)
}
}
}
private func createBody() -> String? {
let messageBody = "hello test message"
return messageBody.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLHostAllowedCharacterSet())
}
private func createNumbers() -> String {
let numbers = ["(111) 222-3333", "(444) 555-6666"]
var tempArray: [String] = []
numbers.forEach { (number: String) in
tempArray.append(number.digitsOnly())
}
return tempArray.joinWithSeparator(",")
}
}
extension String {
func digitsOnly() -> String{
let stringArray = self.componentsSeparatedByCharactersInSet(
NSCharacterSet.decimalDigitCharacterSet().invertedSet)
let newString = stringArray.joinWithSeparator("")
return newString
}
}
With above said I would recommend against using undocumented Apple features for anything you plan on putting on the App Store for the reasons already mentioned in comments.