1
0

49 lines
1.7 KiB
Kotlin

package starter
import org.w3c.dom.Document
import org.w3c.dom.NodeList
import org.xml.sax.InputSource
import java.io.ByteArrayInputStream
import java.io.StringWriter
import javax.xml.parsers.DocumentBuilderFactory
import javax.xml.transform.OutputKeys
import javax.xml.transform.TransformerFactory
import javax.xml.transform.dom.DOMSource
import javax.xml.transform.stream.StreamResult
import javax.xml.xpath.XPathConstants
import javax.xml.xpath.XPathFactory
/*
@see https://stackoverflow.com/a/33541820
*/
fun prettyPrintXml(xml: String, indent: Int = 4): String {
// Turn xml string into a document
val document: Document = DocumentBuilderFactory.newInstance()
.newDocumentBuilder()
.parse(InputSource(ByteArrayInputStream(xml.encodeToByteArray())))
// Remove whitespaces outside tags
document.normalize()
val xPath = XPathFactory.newInstance().newXPath()
val nodeList = xPath.evaluate("//text()[normalize-space()='']",
document,
XPathConstants.NODESET) as NodeList
for (i in 0 until nodeList.length) {
val node = nodeList.item(i)
node.parentNode.removeChild(node)
}
// Setup pretty print options
val transformerFactory = TransformerFactory.newInstance()
transformerFactory.setAttribute("indent-number", indent)
val transformer = transformerFactory.newTransformer()
transformer.setOutputProperty(OutputKeys.ENCODING, "UTF-8")
transformer.setOutputProperty(OutputKeys.OMIT_XML_DECLARATION, "yes")
transformer.setOutputProperty(OutputKeys.INDENT, "yes")
// Return pretty print xml string
val stringWriter = StringWriter()
transformer.transform(DOMSource(document), StreamResult(stringWriter))
return stringWriter.toString()
}