Pretty print XML with Swift 3

Question

使用Swift 2.2我曾经这样修饰XML:

let detxTag = NSXMLElement(name: "detx")
let xml = NSXMLDocument(rootElement: detxTag)
// ...
let data = xml.XMLDataWithOptions(NSXMLNodePrettyPrint | NSXMLNodeCompactEmptyElement)

不幸的是，在Swift 3中不能再使用以下代码(由Xcode 8自动转换):

let detxTag = XMLElement(name: "detx")
let xml = XMLDocument(rootElement: detxTag)
// ...
let data = xml.xmlData(withOptions: NSXMLNodePrettyPrint)

产生以下错误:

Use of unresolved identifier 'NSXMLNodePrettyPrint'

似乎in/out选项已经改变，但它不是很清楚如何使用它:https://developer.apple.com/reference/foundation/xmldocument/input_and_output_options

任何想法?

Answer 1

xmlData(withOptions:)接受XMLNode.Options，但它们必须是转换成Int:

let data = xml.xmlData(withOptions: Int(XMLNode.Options.nodePrettyPrint.rawValue))

或多个选项:

let options: XMLNode.Options = [.nodePrettyPrint, .nodeCompactEmptyElement]
let data = xml.xmlData(withOptions: Int(options.rawValue))

Swift 4， xmlData(withOptions:)取XMLNode.Options参数，因此简化为

let data = xml.xmlData(options: .nodePrettyPrint)

表示单个选项，或者

let data = xml.xmlData(options: [.nodePrettyPrint, .nodeCompactEmptyElement])

Answer 2

Swift 4.2🔸:

if let xml = try? XMLElement.init(xmlString:"<A><b>test</b><c>test</c></A>") {
   let data = xmlDoc.xmlData(options:.nodePrettyPrint)
   let str = String(data: data, encoding: .utf8)!
   print(str)
}
//Output:
<A>
   <b>test</b>
   <c>test</c>
</A>

Answer 3

应该是:

func prettyFormat(xmlString:String) -> String? {
  do {
    let xml = try XMLDocument.init(xmlString: xmlString)
    let data = xml.xmlData(options: .nodePrettyPrint)
    let str:String? = String(data: data, encoding: .utf8)
    return str
  }
  catch {
    print (error.localizedDescription)
  }
  return nil
}

用法:

var str = "Hello, XML Pretty Format playground"
let testStr:String? = "<A><b>test</b>  <c>test</c><d>(str)</d></A>  "

let aStr = prettyFormat(xmlString: "<A><b>test</b>  <c>test</c><d>(str)</d></A>  ")
print (aStr ?? "?")
let bStr = prettyFormat(xmlString:testStr!)
print (bStr ?? "?")

XMLElement。Init不工作…