Fix #259 - better error reporting

import_export/resources.py

@@ -13,6 +13,7 @@
 from django.utils import six
 from django.db.models.fields import FieldDoesNotExist
 from django.db.models.query import QuerySet
+from django.db.transaction import TransactionManagementError
 from django.conf import settings
 
 from .results import Error, Result, RowResult
@@ -45,6 +46,17 @@
 except ImportError:
     from django.utils.datastructures import SortedDict as OrderedDict
 
+# Set default logging handler to avoid "No handler found" warnings.
+import logging
+try:  # Python 2.7+
+    from logging import NullHandler
+except ImportError:
+    class NullHandler(logging.Handler):
+        def emit(self, record):
+            pass
+
+logging.getLogger(__name__).addHandler(NullHandler())
+
 USE_TRANSACTIONS = getattr(settings, 'IMPORT_EXPORT_USE_TRANSACTIONS', False)
 
 
@@ -327,6 +339,7 @@ def import_data(self, dataset, dry_run=False, raise_errors=False,
         try:
             self.before_import(dataset, real_dry_run, **kwargs)
         except Exception as e:
+            logging.exception(e)
             tb_info = traceback.format_exc(2)
             result.base_errors.append(Error(repr(e), tb_info))
             if raise_errors:
@@ -369,8 +382,12 @@ def import_data(self, dataset, dry_run=False, raise_errors=False,
                     row_result.diff = self.get_diff(original, instance,
                             real_dry_run)
             except Exception as e:
+                # There is no point logging a transaction error for each row
+                # when only the original error is likely to be relevant
+                if not isinstance(e, TransactionManagementError):
+                    logging.exception(e)
                 tb_info = traceback.format_exc(2)
-                row_result.errors.append(Error(e, tb_info))
+                row_result.errors.append(Error(e, tb_info, row))
                 if raise_errors:
                     if use_transactions:
                         savepoint_rollback(sp1)
@@ -472,6 +489,7 @@ def __new__(cls, name, bases, attrs):
                         try:
                             f = model._meta.get_field_by_name(attr)[0]
                         except FieldDoesNotExist as e:
+                            logging.exception(e)
                             raise FieldDoesNotExist("%s: %s has no field named '%s'" %
                                 (verbose_path, model.__name__, attr))
 

import_export/results.py

@@ -3,9 +3,10 @@
 
 class Error(object):
 
-    def __init__(self, error, traceback=None):
+    def __init__(self, error, traceback=None, row=None):
         self.error = error
         self.traceback = traceback
+        self.row = row
 
 
 class RowResult(object):

import_export/templates/admin/import_export/import.html

@@ -65,12 +65,16 @@ <h1>{% trans "Import" %}</h1>
     <h2>{% trans "Errors" %}</h2>
     <ul>
       {% for error in result.base_errors  %}
-      <li>{{ error.error }}</li>
+      <li>
+        {{ error.error }}
+        <div class="traceback">{{ error.traceback|linebreaks }}</div>
+      </li>
       {% endfor %}
       {% for line, errors in result.row_errors %}
         {% for error in errors %}
           <li>
             {% trans "Line number" %}: {{ line }} - {{ error.error }}
+            <div>{{ error.row }}</div>
             <div class="traceback">{{ error.traceback|linebreaks }}</div>
           </li>
         {% endfor %}

tests/settings.py

@@ -52,3 +52,15 @@
             'NAME': os.path.join(os.path.dirname(__file__), 'database.db'),
         }
     }
+
+LOGGING = {
+    'version': 1,
+    'disable_existing_loggers': True,
+    'handlers': {
+        'console': {
+            'class': 'logging.NullHandler'
+        }
+    },
+    'root': {
+        'handlers': ['console'],
+    }}