Rework to make DOMImplementation lazy and injectable

src/ol/dom.js

@@ -122,3 +122,32 @@ export function replaceChildren(node, children) {
     node.insertBefore(newChild, oldChild);
   }
 }
+
+let domImplementation_ = undefined;
+
+/**
+ * Register an external DOMImplementation. Can be used to supply a DOMImplementation
+ * in non-browser environments.
+ *
+ * @param {DOMImplementation} domImplementation A DOMImplementation.
+ * @api
+ */
+export function registerDOMImplementation(domImplementation) {
+  domImplementation_ = document;
+}
+
+let document_ = undefined;
+
+/**
+ * Get a document that should be used when creating nodes for XML serializations.
+ * @return {Document} The document.
+ */
+export function getDocument() {
+  if (document_ === undefined) {
+    if (!domImplementation_ && typeof document !== 'undefined') {
+      domImplementation_ = document.implementation;
+    }
+    document_ = domImplementation_.createDocument('', '', null);
+  }
+  return document_;
+}

src/ol/format/xsd.js

@@ -1,7 +1,8 @@
 /**
  * @module ol/format/xsd
  */
-import {getAllTextContent, DOCUMENT} from '../xml.js';
+import {getDocument} from '../dom.js';
+import {getAllTextContent} from '../xml.js';
 import {padNumber} from '../string.js';
 
 
@@ -112,7 +113,7 @@ export function writeBooleanTextNode(node, bool) {
  * @param {string} string String.
  */
 export function writeCDATASection(node, string) {
-  node.appendChild(DOCUMENT.createCDATASection(string));
+  node.appendChild(getDocument().createCDATASection(string));
 }
 
 
@@ -128,7 +129,7 @@ export function writeDateTimeTextNode(node, dateTime) {
       padNumber(date.getUTCHours(), 2) + ':' +
       padNumber(date.getUTCMinutes(), 2) + ':' +
       padNumber(date.getUTCSeconds(), 2) + 'Z';
-  node.appendChild(DOCUMENT.createTextNode(string));
+  node.appendChild(getDocument().createTextNode(string));
 }
 
 
@@ -138,7 +139,7 @@ export function writeDateTimeTextNode(node, dateTime) {
  */
 export function writeDecimalTextNode(node, decimal) {
   const string = decimal.toPrecision();
-  node.appendChild(DOCUMENT.createTextNode(string));
+  node.appendChild(getDocument().createTextNode(string));
 }
 
 
@@ -148,7 +149,7 @@ export function writeDecimalTextNode(node, decimal) {
  */
 export function writeNonNegativeIntegerTextNode(node, nonNegativeInteger) {
   const string = nonNegativeInteger.toString();
-  node.appendChild(DOCUMENT.createTextNode(string));
+  node.appendChild(getDocument().createTextNode(string));
 }
 
 
@@ -157,5 +158,5 @@ export function writeNonNegativeIntegerTextNode(node, nonNegativeInteger) {
  * @param {string} string String.
  */
 export function writeStringTextNode(node, string) {
-  node.appendChild(DOCUMENT.createTextNode(string));
+  node.appendChild(getDocument().createTextNode(string));
 }

src/ol/xml.js

@@ -2,6 +2,7 @@
  * @module ol/xml
  */
 import {extend} from './array.js';
+import {getDocument} from './dom.js';
 
 
 /**
@@ -23,15 +24,6 @@ import {extend} from './array.js';
  */
 
 
-/**
- * This document should be used when creating nodes for XML serializations. This
- * document is also used by {@link module:ol/xml~createElementNS}
- * @const
- * @type {Document}
- */
-export const DOCUMENT = document.implementation.createDocument('', '', null);
-
-
 /**
  * @type {string}
  */
@@ -44,7 +36,7 @@ export const XML_SCHEMA_INSTANCE_URI = 'http://www.w3.org/2001/XMLSchema-instanc
  * @return {Element} Node.
  */
 export function createElementNS(namespaceURI, qualifiedName) {
-  return DOCUMENT.createElementNS(namespaceURI, qualifiedName);
+  return getDocument().createElementNS(namespaceURI, qualifiedName);
 }