Prepend a magic number to bootstrap setup to identify them as valid bootstrap setups

apps/bootstrap/classes.py

@@ -7,9 +7,9 @@ from django.db import models
 from django.core import serializers
 from django.utils.datastructures import SortedDict
 
-from .exceptions import ExistingData
+from .exceptions import ExistingData, NotABootstrapSetup
 from .literals import (FIXTURE_TYPE_PK_NULLIFIER, FIXTURE_TYPE_MODEL_PROCESS,
-    FIXTURE_METADATA_REMARK_CHARACTER)
+    FIXTURE_METADATA_REMARK_CHARACTER, BOOTSTRAP_SETUP_MAGIC_NUMBER)
 from .utils import toposort2
 
 logger = logging.getLogger(__name__)
@@ -38,6 +38,15 @@ class BootstrapModel(object):
     """
     _registry = SortedDict()
 
+    @classmethod
+    def get_magic_number(cls):
+        return '%s %s' % (FIXTURE_METADATA_REMARK_CHARACTER, BOOTSTRAP_SETUP_MAGIC_NUMBER) 
+
+    @classmethod
+    def check_magic_number(cls, data):
+        if not data.startswith(cls.get_magic_number()):
+            raise NotABootstrapSetup
+
     @classmethod
     def check_for_data(cls):
         for model in cls.get_all():

apps/bootstrap/exceptions.py

@@ -8,3 +8,11 @@ class ExistingData(Exception):
     bootstrap's fixture.
     """
     pass
+
+
+class NotABootstrapSetup(Exception):
+    """
+    Raised when an attempting to import a bootstrap setup without a proper
+    magic number metadata
+    """
+    pass

apps/bootstrap/literals.py

@@ -74,3 +74,5 @@ FIXTURE_METADATA_NAME = 'name'
 FIXTURE_METADATA_SLUG = 'slug'
 FIXTURE_METADATA_DESCRIPTION = 'description'
 BOOTSTRAP_EXTENSION = 'txt'
+
+BOOTSTRAP_SETUP_MAGIC_NUMBER = 'bootstrap setup'

apps/bootstrap/managers.py

@@ -8,8 +8,7 @@ from django.db import models
 from django.core import serializers
 
 from .classes import BootstrapModel, FixtureMetadata
-from .literals import (FIXTURE_TYPE_FIXTURE_PROCESS, FIXTURE_TYPE_EMPTY_FIXTURE,
-    DEFAULT_REPOSITORY)
+from .literals import (FIXTURE_TYPE_FIXTURE_PROCESS, FIXTURE_TYPE_EMPTY_FIXTURE)
 
 logger = logging.getLogger(__name__)
 
@@ -30,6 +29,7 @@ class BootstrapSetupManager(models.Manager):
         return FIXTURE_TYPE_FIXTURE_PROCESS[serialization_format]('\n'.join(result))
 
     def import_setup(self, file_data):
+        BootstrapModel.check_magic_number(file_data)
         metadata = FixtureMetadata.read_all(file_data)
         instance = self.model(fixture=file_data, **metadata)
         instance.save(update_metadata=False)

apps/bootstrap/models.py

@@ -91,7 +91,8 @@ class BootstrapSetup(models.Model):
     def save(self, *args, **kwargs):
         update_metadata = kwargs.pop('update_metadata', True)
         if update_metadata:
-            self.fixture = '%s\n%s' % (
+            self.fixture = '%s\n%s\n%s' % (
+                BootstrapModel.get_magic_number(),
                 self.get_metadata_string(),
                 self.cleaned_fixture
             )

apps/bootstrap/views.py

@@ -20,7 +20,7 @@ from .permissions import (PERMISSION_BOOTSTRAP_VIEW, PERMISSION_BOOTSTRAP_CREATE
     PERMISSION_BOOTSTRAP_EXPORT, PERMISSION_BOOTSTRAP_IMPORT)
 from .forms import (BootstrapSetupForm, BootstrapSetupForm_view, BootstrapSetupForm_dump,
     BootstrapSetupForm_edit, BootstrapFileImportForm, BootstrapURLImportForm)
-from .exceptions import ExistingData
+from .exceptions import ExistingData, NotABootstrapSetup
 
 
 def bootstrap_setup_list(request):
@@ -239,6 +239,8 @@ def bootstrap_setup_import_from_file(request):
                 BootstrapSetup.objects.import_from_file(request.FILES['file'])
                 messages.success(request, _(u'Bootstrap setup imported successfully.'))
                 return HttpResponseRedirect(reverse('bootstrap_setup_list'))
+            except NotABootstrapSetup:
+                messages.error(request, _(u'File is not a bootstrap setup.'))
             except Exception as exception:
                 messages.error(request, exception)
                 return HttpResponseRedirect(previous)
@@ -265,6 +267,8 @@ def bootstrap_setup_import_from_url(request):
                 BootstrapSetup.objects.import_from_url(form.cleaned_data['url'])
                 messages.success(request, _(u'Bootstrap setup imported successfully.'))
                 return HttpResponseRedirect(reverse('bootstrap_setup_list'))
+            except NotABootstrapSetup:
+                messages.error(request, _(u'Data from URL is not a bootstrap setup.'))
             except Exception as exception:
                 messages.error(request, exception)
                 return HttpResponseRedirect(previous)