whitespace.swift

import Foundation

extension String {
    func containsOnlyWhitespace() -> Bool {
        let pattern = "^[\\s]+$"
        let regex = try! NSRegularExpression(pattern: pattern, options: .DotMatchesLineSeparators)
        let matches = regex.matchesInString(self, options: .ReportCompletion, range: NSMakeRange(0, self.characters.count))
        return matches.count > 0
    }
}

Thanks!