fix loading extensions in standalone packages

The extension files were still being bundled in with the main JS and CSS files, but that's not how Numbas expects to load extensions any more.

I also accidentally broke the embedding of the extension data in the last commit.

Author: christianp

bin/numbas.py

@@ -302,7 +302,7 @@ def make_xml(self):
         self.xmls = xml2js.settings_js_template.format(**{
             'numbas_version': NUMBAS_VERSION,
             'rawxml': json.dumps({'templates': xslts}),
-            'extensionfiles': [f'extensions/{x}/{x}.js' for x in self.extensions],
+            'deps': [],
         })
 
     def render_templates(self):
@@ -423,7 +423,7 @@ def collect_stylesheets(self):
         for dst, src in self.files.items():
             if Path(dst).suffix != '.css':
                 continue
-            if not any(p.name == 'standalone_scripts' for p in Path(dst).parents):
+            if not any(p in ('standalone_scripts', 'extensions') for p in Path(dst).parts[:-1]):
                 stylesheets.append((dst, src))
 
         stylesheets.sort(key=lambda x:x[0])
@@ -441,7 +441,7 @@ def collect_scripts(self):
         for dst, src in self.files.items():
             if Path(dst).suffix != '.js':
                 continue
-            if not any(p.name == 'standalone_scripts' for p in Path(dst).parents):
+            if not any(p in ('standalone_scripts', 'extensions') for p in Path(dst).parts[:-1]):
                 javascripts.append((dst, src))
 
         for dst, src in javascripts:

bin/xml2js.py

@@ -22,7 +22,7 @@ def encode(xml):
     xml = re.sub('"','\\"',xml)
     return xml
 
-settings_js_template = """Numbas.queueScript('settings',{extensionfiles},function() {{
+settings_js_template = """Numbas.queueScript('settings',{deps},function() {{
     Numbas.version = {numbas_version};
 
     Numbas.rawxml = {rawxml};

runtime/scripts/jme-variables.js

@@ -860,7 +860,7 @@ DOMcontentsubber.prototype = {
             /** Substitute content into the object's root element.
              */
             function go() {
-                const rootElement = element.contentDocument.rootElement;
+                const rootElement = element.contentDocument?.rootElement;
                 if(!rootElement) {
                     return;
                 }

themes/default/templates/index.html

@@ -32,7 +32,7 @@
             {% if not dont_start_exam %}
             <numbas-exam storage="scorm">
                 <script type="application/numbas-exam">{{options.source|safe_script}}</script>
-                <script type="application/json" slot="extension-data">{{extension_data|tojson}}</script>
+                <script type="application/json" slot="extension-data">{{extension_data}}</script>
             </numbas-exam>
             {% endif %}
         </div>