for externalresponse - fallback to script code if <answer> code not provided

common/lib/capa/capa_problem.py

@@ -286,6 +286,7 @@ class LoncapaProblem(object):
         context.update(global_context)            		# initialize context to have stuff in global_context
         context['__builtins__'] = globals()['__builtins__']    	# put globals there also
         context['the_lcp'] = self                		# pass instance of LoncapaProblem in
+        context['script_code'] = ''
 
         for script in tree.findall('.//script'):
             stype = script.get('type')
@@ -298,8 +299,9 @@ class LoncapaProblem(object):
             code = script.text
             XMLESC = {"'": "'", """: '"'}
             code = unescape(code, XMLESC)
+            context['script_code'] += code		# store code source in context
             try:
-                exec code in context, context        # use "context" for global context; thus defs in code are global within code
+                exec code in context, context        	# use "context" for global context; thus defs in code are global within code
             except Exception:
                 log.exception("Error while execing code: " + code)
         return context

common/lib/capa/responsetypes.py

@@ -746,12 +746,20 @@ main()
         xml = self.xml
         self.url = xml.get('url') or "http://eecs1.mit.edu:8889/pyloncapa"	# FIXME - hardcoded URL
 
-        answer = xml.xpath('//*[@id=$id]//answer',id=xml.get('id'))[0]	# FIXME - catch errors
-        answer_src = answer.get('src')
-        if answer_src is not None:
-            self.code = self.system.filesystem.open('src/'+answer_src).read()
-        else:
-            self.code = answer.text
+        # answer = xml.xpath('//*[@id=$id]//answer',id=xml.get('id'))[0]	# FIXME - catch errors
+        answer = xml.find('answer')
+        if answer is not None:
+            answer_src = answer.get('src')
+            if answer_src is not None:
+                self.code = self.system.filesystem.open('src/'+answer_src).read()
+            else:
+                self.code = answer.text
+        else:					# no <answer> stanza; get code from <script>
+            self.code = self.context['script_code']
+            if not self.code:
+                msg = '%s: Missing answer script code for externalresponse' % unicode(self)
+                msg += "\nSee XML source line %s" % getattr(self.xml,'sourceline','<unavailable>')
+                raise LoncapaProblemError(msg)
 
         self.tests = xml.get('tests')
 

lms/envs/dev_ike.py

@@ -47,7 +47,7 @@ COURSE_SETTINGS =  {'6.002_Spring_2012': {'number' : '6.002x',
                                          },
                     '6.189_Spring_2013': {'number' : '6.189x',
                                          'title'  : 'IAP Python Programming',
-                                         'xmlpath': '/6189-pytutor/',
+                                         'xmlpath': '/6.189x/',
                                           'active' : True,
                                          },
                     '8.01_Summer_2012': {'number' : '8.01x',