Convert string to NSURL with character '\\' inside - ios

Question

I coding with Swift 2.0.
I got my URL string like this:
let urlString = "http://example.com/api/getfile/?filepath=C:\\1.txt"
When I convert it into NSURL, it returns nil.
let OrginUrl = NSURL(string: urlString)
Anyone know how to do this?

Answer 1

There are two issues that need to be addressed:
In order to include a \ it must be escaped because it is itself the escape character.
'\' characters are not allowed in URLs so they need to be URL encoded
let urlString = "http://example.com/api/getfile/?filepath=C:\\\\1.txt"
print("urlString: \(urlString)")
var escapedString = urlString.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLHostAllowedCharacterSet())
print("escapedString!: \(escapedString!)")
let orginUrl = NSURL(string: escapedString!)
print("orginUrl: \(orginUrl!)")
urlString:
http://example.com/api/getfile/?filepath=C:\\1.txt
escapedString!:
http%3A%2F%2Fexample.com%2Fapi%2Fgetfile%2F%3Ffilepath=C%3A%5C%5C1.txt
orginUrl:
http%3A%2F%2Fexample.com%2Fapi%2Fgetfile%2F%3Ffilepath=C%3A%5C%5C1.txt

Answer 2

You should use unicode instead of backslash twice.
stringByAddingPercentEscapesUsingEncoding is deprecated: Use stringByAddingPercentEncodingWithAllowedCharacters(_:) instead, which always uses the recommended UTF-8 encoding, and which encodes for a specific URL components or subcomponents since each URL component or subcomponent has different rules for what characters are valid.
Documentation Reference
Below is the example code:
let myLink = "http://example.com/api/getfile/?filepath=C:\u{005C}\u{005C}1.txt"
var newLink = ""
if let queryIndex = myLink.characters.indexOf("?"){
newLink += myLink.substringToIndex(queryIndex.successor())
if let filePathIndex = myLink.characters.indexOf("=")?.successor() {
newLink += myLink.substringWithRange(queryIndex.successor()...filePathIndex.predecessor())
let filePath = myLink.substringFromIndex(filePathIndex)
if let pathEscaped = filePath.stringByAddingPercentEncodingWithAllowedCharacters(NSCharacterSet.URLPathAllowedCharacterSet()) {
newLink += pathEscaped
}
}
}
if let newURL = NSURL(string: newLink) {
print(newURL, separator: "", terminator: "")
} else {
print("invalid")
}
And result you will get:
"http://example.com/api/getfile/?filepath=C%3A%5C%5C1.txt"