Issue #5011 - Moves formmail template load to handler creation

sitescripts/formmail/web/formmail2.py

 # This file is part of the Adblock Plus web scripts,
 # Copyright (C) 2006-2016 Eyeo GmbH
 #
 # Adblock Plus is free software: you can redistribute it and/or modify
 # it under the terms of the GNU General Public License version 3 as
 # published by the Free Software Foundation.
 #
 # Adblock Plus is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
 #
 # You should have received a copy of the GNU General Public License
 # along with Adblock Plus.  If not, see <http://www.gnu.org/licenses/>.
 
 import datetime
 import collections
 
-from sitescripts.utils import get_config, sendMail, encode_email_address
+from sitescripts.utils import (get_config, sendMail, encode_email_address,
+                               get_template)
 from sitescripts.web import registerUrlHandler, form_handler
 
 
 def get_config_items():
     config = get_config()
     default_keys = set(config.defaults())
     for name, value in config.items('formmail2'):
         if name not in default_keys:
             yield name, value
 
@@ skipping 19 matching lines @@
 def make_error(spec, check_type, default_message):
     if check_type in spec:
         return spec[check_type].value
     return default_message
 
 
 def make_handler(name, config):
     try:
         url = config['url'].value
     except (KeyError, AttributeError):
-        raise Exception('No URL configured for form handler:' + name)
+        raise Exception('No URL configured for form handler: ' + name)
     try:
         template = config['template'].value
+        get_template(template, autoescape=False)
     except (KeyError, AttributeError):
-        raise Exception('No template configured for form handler:' + name)
+        raise Exception('No template configured for form handler: ' + name)
     try:
         fields = config['fields']
         for field, spec in fields.items():
             spec.value = {s.strip() for s in spec.value.split(',')}
     except KeyError:
-        raise Exception('No fields configured for form handler:' + name)
+        raise Exception('No fields configured for form handler: ' + name)
     if len(fields) == 0:
-        raise Exception('No fields configured for form handler:' + name)
+        raise Exception('No fields configured for form handler: ' + name)
 
     @form_handler
     def handler(environ, start_response, params):
         response_headers = [('Content-Type', 'text/plain; charset=utf-8')]
         errors = []
         for field, spec in fields.items():
             if 'mandatory' in spec.value:
                 if field not in params.keys():
                     errors.append(make_error(spec, 'mandatory',
                                              'No {} entered'.format(field)))
@@ skipping 14 matching lines @@
         start_response('200 OK', response_headers)
         return ''
 
     return url, handler
 
 
 conf_dict = conf_parse(get_config_items())
 for name, config in conf_dict.items():
     url, handler = make_handler(name, config)
     registerUrlHandler(url, handler)