Parse xml

XmlParser.kt

package au.suby.data.api.youtube.wrappers

import org.w3c.dom.Document
import org.w3c.dom.Element
import org.w3c.dom.Node
import org.w3c.dom.NodeList

@Suppress("unused")
class XmlParser {

    fun <T> parse(
        xmlDoc: Document,
        tag: String,
        visitor: ((node: Element, attributes: Map<String, String>) -> T)
    ): List<T> {

        val nodes: NodeList = xmlDoc.getElementsByTagName(tag)

        val objects = arrayListOf<T>()

        for (i in 0 until nodes.length) {
            val node: Node = nodes.item(i)

            if (node.nodeType == Node.ELEMENT_NODE) {

                val elem = node as Element
                val attributes = mutableMapOf<String, String>()
                for (j in 0 until elem.attributes.length) {
                    attributes.putIfAbsentt(
                        elem.attributes.item(j).nodeName,
                        elem.attributes.item(j).nodeValue
                    )
                }

                objects.add(visitor(node, attributes))
            }
        }
        return objects
    }

    fun <T> parse(
        xmlDoc: Node,
        visitor: ((node: Element, attributes: Map<String, String>) -> T)
    ): List<T> {

        val nodes: NodeList = xmlDoc.childNodes

        val objects = arrayListOf<T>()

        for (i in 0 until nodes.length) {
            val node: Node = nodes.item(i)

            if (node.nodeType == Node.ELEMENT_NODE) {

                val elem = node as Element
                val attributes = mutableMapOf<String, String>()
                for (j in 0 until elem.attributes.length) {
                    attributes.putIfAbsentt(
                        elem.attributes.item(j).nodeName,
                        elem.attributes.item(j).nodeValue
                    )
                }

                objects.add(visitor(node, attributes))
            }
        }
        return objects
    }

    private fun <K, V> MutableMap<K, V>.putIfAbsentt(key: K, value: V): V? {
        var v: V? = get(key)
        if (v == null) {
            v = put(key, value)
        }
        return v
    }
}