fixed #2251

(sorta, load project anyway even though costumes / sounds are missing)
The cause for this defect is usually prior use of IE when saving a project

HISTORY.md

@@ -6,6 +6,7 @@
 * BYOB: updated version date
 * Objects: fixed #2250
 * Frequency Distribution Analysis library: added "pipe" and "lower case" blocks
+* Store, XML: fixed #2251 (sorta, load project anyway even though costumes / sounds are missing)
 
 ## v4.2.2.6
 ###2018-11-06

snap.html

@@ -16,8 +16,8 @@
         <script type="text/javascript" src="src/tables.js?version=2018-10-02"></script>
         <script type="text/javascript" src="src/symbols.js?version=2018-10-02"></script>
         <script type="text/javascript" src="src/sketch.js?version=2018-10-02"></script>
-        <script type="text/javascript" src="src/xml.js?version=2018-10-02"></script>
-        <script type="text/javascript" src="src/store.js?version=2018-10-05"></script>
+        <script type="text/javascript" src="src/xml.js?version=2018-11-12"></script>
+        <script type="text/javascript" src="src/store.js?version=2018-11-12"></script>
         <script type="text/javascript" src="src/locale.js?version=2018-11-06"></script>
         <script type="text/javascript" src="src/cloud.js?version=2018-10-04"></script>
         <script type="text/javascript" src="src/sha512.js?version=2018-10-02"></script>

src/store.js

@@ -61,7 +61,7 @@ normalizeCanvas, contains*/
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.store = '2018-October-05';
+modules.store = '2018-November-12';
 
 
 // XML_Serializer ///////////////////////////////////////////////////////
@@ -819,7 +819,14 @@ SnapSerializer.prototype.loadCostumes = function (object, model) {
     var costumes = model.childNamed('costumes'),
         costume;
     if (costumes) {
-        object.costumes = this.loadValue(costumes.require('list'));
+        object.costumes = this.loadValue(costumes.require(
+            'list',
+            function () {
+                console.log(object.name + ': missing required costumes list, ' +
+                    'improvising...');
+                return new XML_Element('list');
+            }
+        ));
         object.costumes.type = 'costume';
     }
     if (Object.prototype.hasOwnProperty.call(
@@ -844,7 +851,16 @@ SnapSerializer.prototype.loadSounds = function (object, model) {
     // private
     var sounds = model.childNamed('sounds');
     if (sounds) {
-        object.sounds = this.loadValue(sounds.require('list'));
+        // object.sounds = this.loadValue(sounds.require('list')); +++
+        object.sounds = this.loadValue(sounds.require(
+            'list',
+            function () {
+                console.log(object.name + ': missing required sounds list, ' +
+                    'improvising...');
+                return new XML_Element('list');
+            }
+        ));
+
         object.sounds.type = 'sound';
     }
 };

src/xml.js

@@ -7,7 +7,7 @@
     written by Jens Mönig
     jens@moenig.org
 
-    Copyright (C) 2015 by Jens Mönig
+    Copyright (C) 2018 by Jens Mönig
 
     This file is part of Snap!.
 
@@ -67,7 +67,7 @@
 
 // Global stuff ////////////////////////////////////////////////////////
 
-modules.xml = '2017-November-15';
+modules.xml = '2018-November-12';
 
 // Declarations
 
@@ -178,11 +178,18 @@ XML_Element.prototype.init = function (tag, contents, parent) {
 
 // XML_Element DOM navigation: (aside from what's inherited from Node)
 
-XML_Element.prototype.require = function (tagName) {
-    // answer the first direct child with the specified tagName, or throw
-    // an error if it doesn't exist
+XML_Element.prototype.require = function (tagName, fallback) { // +++
+    // answer the first direct child with the specified tagName.
+    // if it doesn't exist execute the fallback function or return the
+    // fallback value, otherwise throw an error
     var child = this.childNamed(tagName);
     if (!child) {
+        if (fallback instanceof Function) {
+            return fallback();
+        }
+        if (!isNil(fallback)) {
+            return fallback;
+        }
         throw new Error('Missing required element <' + tagName + '>!');
     }
     return child;