Add Xml parsing support to js platform (#3105)

* First pass at adding Xml parsing support to js platform

Likely still need to add tests and samples

* Add JS to Parser Node and Element converter

Mirrors native impl by returning empty strings when content is unavailable

Moves MalformedXMLException out of native code, useful for common case.

* Remove unneeded null checks in Parser

Last commit handled null management

* Add newlines for code linter

* Fix namespaceUri bug

Undo accidental capture of localName

Also remove unneeded null check

* Undo grade.properies change

Had to disable webpack version number property to run sample

* Clean up NodeImpl comments

Corrected description

* Make NodeList impl lazy

Generates only when needed, serves cache after

components/resources/library/src/commonMain/kotlin/org/jetbrains/compose/resources/vector/xmldom/MalformedXMLException.kt

@@ -0,0 +1,6 @@
+package org.jetbrains.compose.resources.vector.xmldom
+
+/**
+ * Error throw when parsed XML is malformed
+ */
+class MalformedXMLException(message: String?) : Exception(message)

components/resources/library/src/jsMain/kotlin/org/jetbrains/compose/resources/Resource.js.kt

@@ -6,8 +6,11 @@
 package org.jetbrains.compose.resources
 
 import org.jetbrains.compose.resources.vector.xmldom.Element
+import org.jetbrains.compose.resources.vector.xmldom.ElementImpl
+import org.jetbrains.compose.resources.vector.xmldom.MalformedXMLException
 import org.khronos.webgl.ArrayBuffer
 import org.khronos.webgl.Int8Array
+import org.w3c.dom.parsing.DOMParser
 import org.w3c.xhr.ARRAYBUFFER
 import org.w3c.xhr.XMLHttpRequest
 import org.w3c.xhr.XMLHttpRequestResponseType
@@ -45,7 +48,10 @@ internal actual class MissingResourceException actual constructor(path: String)
     Exception("Missing resource with path: $path")
 
 internal actual fun parseXML(byteArray: ByteArray): Element {
-    throw UnsupportedOperationException("XML Vector Drawables are not supported for Web target")
+    val xmlString = byteArray.decodeToString()
+    val xmlDom = DOMParser().parseFromString(xmlString, "application/xml")
+    val domElement = xmlDom.documentElement ?: throw MalformedXMLException("missing documentElement")
+    return ElementImpl(domElement)
 }
 
 internal actual fun isSyncResourceLoadingSupported() = false

components/resources/library/src/jsMain/kotlin/org/jetbrains/compose/resources/xmldom/ElementImpl.kt

@@ -0,0 +1,17 @@
+package org.jetbrains.compose.resources.vector.xmldom
+
+import org.w3c.dom.Element as DomElement
+
+internal class ElementImpl(val element: DomElement): NodeImpl(element), Element {
+
+    override val localName: String
+        get() = element.localName
+
+    override val namespaceURI: String
+        get() = element.namespaceURI ?: ""
+
+    override fun getAttributeNS(nameSpaceURI: String, localName: String): String =
+        element.getAttributeNS(nameSpaceURI, localName) ?: ""
+
+    override fun getAttribute(name: String): String  = element.getAttribute(name) ?: ""
+}

components/resources/library/src/jsMain/kotlin/org/jetbrains/compose/resources/xmldom/NodeImpl.kt

@@ -0,0 +1,28 @@
+package org.jetbrains.compose.resources.vector.xmldom
+
+import org.w3c.dom.Node as DomNode
+import org.w3c.dom.Element as DomElement
+
+internal open class NodeImpl(val n: DomNode): Node {
+    override val nodeName: String
+        get() = n.nodeName
+
+    override val localName = "" /* localName is not a Node property, only applies to Elements and Attrs */
+
+    override val namespaceURI = "" /* namespaceURI is not a Node property, only applies to Elements and Attrs */
+
+    override val childNodes: NodeList by lazy {
+        object: NodeList {
+            override fun item(i: Int): Node {
+                val child = n.childNodes.item(i)
+                    ?: throw IndexOutOfBoundsException("no child node accessible at index=$i")
+                return if (child is DomElement) ElementImpl(child) else NodeImpl(child)
+            }
+
+            override val length: Int = n.childNodes.length
+        }
+    }
+
+    override fun lookupPrefix(namespaceURI: String): String = n.lookupPrefix(namespaceURI) ?: ""
+
+}

components/resources/library/src/nativeMain/kotlin/org/jetbrains/compose/resources/vector/xmldom/DomXmlParser.kt

@@ -4,6 +4,7 @@
  */
 package org.jetbrains.compose.resources.vector.xmldom
 
+import org.jetbrains.compose.resources.vector.xmldom.MalformedXMLException
 import platform.Foundation.*
 import platform.darwin.NSObject
 
@@ -17,8 +18,6 @@ internal fun parse(xml: String): Element {
     return parser.root!!
 }
 
-class MalformedXMLException(message: String?) : Exception(message)
-
 private class ElementImpl(override val localName: String,
                           override val nodeName: String,
                           override val namespaceURI: String,