Improved TemplateValidator error reporting to include origins and line numbers in...

diff --git a/validators.py b/validators.py
index 8b39abd..5ae9409 100644 (file)
--- a/validators.py
+++ b/validators.py
@@ -3,6 +3,7 @@ from django.core.validators import RegexValidator
 from django.core.exceptions import ValidationError
 from django.template import Template, Parser, Lexer, TOKEN_BLOCK, TOKEN_VAR, TemplateSyntaxError
 from django.utils import simplejson as json
+from django.utils.html import escape, mark_safe
 import re
 from philo.utils import LOADED_TEMPLATE_ATTR
 
@@ -116,6 +117,16 @@ class TemplateValidationParser(Parser):
                raise ValidationError('Tag "%s" is not permitted here.' % command)
 
 
+def linebreak_iter(template_source):
+       # Cribbed from django/views/debug.py
+       yield 0
+       p = template_source.find('\n')
+       while p >= 0:
+               yield p+1
+               p = template_source.find('\n', p+1)
+       yield len(template_source) + 1
+
+
 class TemplateValidator(object): 
        def __init__(self, allow=None, disallow=None, secure=True):
                self.allow = allow
@@ -128,6 +139,14 @@ class TemplateValidator(object):
                except ValidationError:
                        raise
                except Exception, e:
+                       if hasattr(e, 'source') and isinstance(e, TemplateSyntaxError):
+                               origin, (start, end) = e.source
+                               template_source = origin.reload()
+                               upto = 0
+                               for num, next in enumerate(linebreak_iter(template_source)):
+                                       if start >= upto and end <= next:
+                                               raise ValidationError(mark_safe("Template code invalid: \"%s\" (%s:%d).<br />%s" % (escape(template_source[start:end]), origin.loadname, num, e)))
+                                       upto = next
                        raise ValidationError("Template code invalid. Error was: %s: %s" % (e.__class__.__name__, e))
        
        def validate_template(self, template_string):