XML

XMLToDict.swift

public class XMLToDict: NSObject {
  public static let kText = "XMLToDictTextKey"
  public static let kAttributes = "_XMLAttributes"
    
  private var stack = [NSMutableDictionary]()
  private var textBeingProcessed = ""
}

public extension XMLToDict {
  static func makeDict(data: Data) -> [String:Any]? {
    let parser = XMLToDict()
    return parser.dictFrom(data: data)
  }
}

public extension XMLToDict {
  func dictFrom(data: Data) -> [String : Any]? {
    stack = [NSMutableDictionary]()
    textBeingProcessed = ""
    stack.append(NSMutableDictionary())
    
    let parser = XMLParser(data: data)
    parser.delegate = self
    parser.parse()
    
    return stack.first as? [String : Any]
  }
}


// MARK: - XMLParserDelegate
extension XMLToDict: XMLParserDelegate {
  public func parser(_ parser: XMLParser, didStartElement elementName: String, namespaceURI: String?, qualifiedName qName: String?, attributes attributeDict: [String : String] = [:]) {
    guard let parent = stack.last else {
      fatalError()
    }
    
    let child = NSMutableDictionary()
    if attributeDict.count > 0 {
      child.setObject(attributeDict, forKey: XMLToDict.kAttributes as NSString)
    }
    
    if let existingValue = parent[elementName] {
      let array: NSMutableArray
      
      if let currentArray = existingValue as? NSMutableArray {
        array = currentArray
      } else {
        array = NSMutableArray()
        array.add(existingValue)
        parent[elementName] = array
      }
      
      array.add(child)
    } else {
      parent[elementName] = child
      stack[stack.endIndex - 1] = parent
    }
    
    stack.append(child)
  }
  
  public func parser(_ parser: XMLParser, foundCharacters string: String) {
    let trimmedString = string.trimmingCharacters(in: .whitespacesAndNewlines)
    textBeingProcessed.append(trimmedString)
  }
  
  public func parser(_ parser: XMLParser, didEndElement elementName: String, namespaceURI: String?, qualifiedName qName: String?) {
    guard let lastDict = stack.last else {
      fatalError()
    }
    
    let parent = stack[stack.endIndex - 2]
    
    if textBeingProcessed.count > 0 {
      if lastDict.count > 0 {
        lastDict[XMLToDict.kText] = textBeingProcessed
      } else if let array = parent[elementName] as? NSMutableArray {
        array.removeLastObject()
        array.add(textBeingProcessed)
      } else {
        parent[elementName] = textBeingProcessed
      }
    } else if lastDict.count == 0 {
      parent.removeObject(forKey: elementName)
    }
    
    textBeingProcessed = ""
    stack.removeLast()
  }
  
  public func parser(_ parser: XMLParser, parseErrorOccurred parseError: Error) {
    print(parseError)
  }
}