Moved problem HTML error handling to its own function

common/lib/xmodule/xmodule/capa_module.py

@@ -319,13 +319,15 @@ class CapaModule(XModule):
             else:
                 return True
 
-    def get_problem_html(self, encapsulate=True):
-        '''Return html for the problem.  Adds check, reset, save buttons
-        as necessary based on the problem config and state.'''
+    def handle_problem_html_error(self, err):
+        """
+        Change our problem to a dummy problem containing
+        a warning message to display to users.
 
-        try:
-            html = self.lcp.get_html()
-        except Exception, err:
+        Returns the HTML to show to users
+
+        *err* is the Exception encountered while rendering the problem HTML.
+        """
         log.exception(err)
 
         # TODO (vshnayder): another switch on DEBUG.
@@ -337,9 +339,10 @@ class CapaModule(XModule):
             msg += '<p>Error:</p><p><pre>%s</pre></p>' % str(err).replace('<', '&lt;')
             msg += '<p><pre>%s</pre></p>' % traceback.format_exc().replace('<', '&lt;')
             html = msg
-            else:
+
         # We're in non-debug mode, and possibly even in production. We want
         #   to avoid bricking of problem as much as possible
+        else:
 
             # Presumably, student submission has corrupted LoncapaProblem HTML.
             #   First, pull down all student answers
@@ -380,6 +383,19 @@ class CapaModule(XModule):
                 log.exception(err)
                 raise
 
+        return html
+
+
+    def get_problem_html(self, encapsulate=True):
+        '''Return html for the problem.  Adds check, reset, save buttons
+        as necessary based on the problem config and state.'''
+
+        try:
+            html = self.lcp.get_html()
+
+        except Exception, err:
+            return self.handle_problem_html_error(err)
+
         content = {'name': self.display_name,
                    'html': html,
                    'weight': self.descriptor.weight,