Alamofireのカスタムエンコード

custom_encode.swift

func makeCustomEncoding() -> ParameterEncoding {
        return ParameterEncoding.Custom { requestConvertible, parameters in
            func escape(string: String) -> String {
                // MEMO: /, ? もエンコードされるようにオリジナルのコードに追加指定している
                // see https://github.com/Alamofire/Alamofire/blob/master/Source/ParameterEncoding.swift#L220
                //
                let generalDelimitersToEncode = ":#[]@/?" // does not include "?" or "/" due to RFC 3986 - Section 3.4
                let subDelimitersToEncode = "!$&'()*+,;="
                
                let allowedCharacterSet = NSCharacterSet.URLQueryAllowedCharacterSet().mutableCopy() as! NSMutableCharacterSet
                allowedCharacterSet.removeCharactersInString(generalDelimitersToEncode + subDelimitersToEncode)
                
                var escaped = ""
                
                if #available(iOS 8.3, OSX 10.10, *) {
                    escaped = string.stringByAddingPercentEncodingWithAllowedCharacters(allowedCharacterSet) ?? string
                } else {
                    let batchSize = 50
                    var index = string.startIndex
                    
                    while index != string.endIndex {
                        let startIndex = index
                        let endIndex = index.advancedBy(batchSize, limit: string.endIndex)
                        let range = startIndex..<endIndex
                        
                        let substring = string.substringWithRange(range)
                        
                        escaped += substring.stringByAddingPercentEncodingWithAllowedCharacters(allowedCharacterSet) ?? substring
                        
                        index = endIndex
                    }
                }
                
                return escaped
            }
            
            let mutableURLRequest = requestConvertible.URLRequest

            guard var parameters = parameters else {
                return (mutableURLRequest, nil)
            }
            
            for (key, value) in parameters {
                parameters[escape(key)] = escape("\(value)")
            }
            
            let query = "?" + (parameters.map { "\($0)=\($1)" } as [String]).joinWithSeparator("&")
            
            mutableURLRequest.URL = NSURL(string: mutableURLRequest.URLString.stringByAppendingString(query))
            
            return (mutableURLRequest, nil)
        }
    }