links_header_parser.swift

/** Get formatted links from links header
*/
func getLinksFromHeader(linksString: String?) -> [String: String] {
    var res = [String: String]()

    if linksString == nil { return res }
    
    var err: NSError?
    let relRegex = NSRegularExpression(pattern: "rel=\\\"?([^\\\"]+)\\\"?", options: .CaseInsensitive, error: &err)

    var trimChars = NSCharacterSet.whitespaceCharacterSet().mutableCopy() as NSMutableCharacterSet
    trimChars.addCharactersInString("<>")

    for link in linksString!.componentsSeparatedByString(",") {
        let semicolonPosition = link.rangeOfString(";")
        
        if semicolonPosition == nil { continue }

        let target = link.substringToIndex(semicolonPosition!.startIndex).stringByTrimmingCharactersInSet(trimChars)

        if target.utf16Count == 0 { continue }
        
        let match = relRegex?.firstMatchInString(link, options: .allZeros, range: NSMakeRange(0, link.utf16Count))

        if let m = match {
            let type = (link as NSString).substringWithRange(m.rangeAtIndex(1))

            res[type] = target
        }
    }
    
    return res
}