Add SessionProgress class.

tailbone/progress.py

@@ -0,0 +1,78 @@
+#!/usr/bin/env python
+# -*- coding: utf-8  -*-
+################################################################################
+#
+#  Rattail -- Retail Software Framework
+#  Copyright © 2010-2012 Lance Edgar
+#
+#  This file is part of Rattail.
+#
+#  Rattail is free software: you can redistribute it and/or modify it under the
+#  terms of the GNU Affero General Public License as published by the Free
+#  Software Foundation, either version 3 of the License, or (at your option)
+#  any later version.
+#
+#  Rattail 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 Affero General Public License for
+#  more details.
+#
+#  You should have received a copy of the GNU Affero General Public License
+#  along with Rattail.  If not, see <http://www.gnu.org/licenses/>.
+#
+################################################################################
+
+"""
+Progress Indicator
+"""
+
+from beaker.session import Session
+
+
+def get_progress_session(session, key):
+    request = session.request
+    id = '%s.progress.%s' % (session.id, key)
+    session = Session(request, id)
+    return session
+
+
+class SessionProgress(object):
+    """
+    Provides a session-based progress bar mechanism.
+
+    This class is only responsible for keeping the progress *data* current.  It
+    is the responsibility of some client-side AJAX (etc.) to consume the data
+    for display to the user.
+    """
+
+    def __init__(self, session, key):
+        self.session = get_progress_session(session, key)
+        self.canceled = False
+        self.clear()
+
+    def __call__(self, message, maximum):
+        self.clear()
+        self.session['message'] = message
+        self.session['maximum'] = maximum
+        self.session['value'] = 0
+        self.session.save()
+        return self
+
+    def clear(self):
+        self.session.clear()
+        self.session['complete'] = False
+        self.session['error'] = False
+        self.session['canceled'] = False
+        self.session.save()
+
+    def update(self, value):
+        self.session.load()
+        if self.session.get('canceled'):
+            self.canceled = True
+        else:
+            self.session['value'] = value
+            self.session.save()
+        return not self.canceled
+
+    def destroy(self):
+        pass

tailbone/views/batches/core.py

@@ -35,8 +35,8 @@ import edbob
 from edbob.pyramid.forms import PrettyDateTimeFieldRenderer
 from ...forms import EnumFieldRenderer
 from ...grids.search import BooleanSearchFilter
-from edbob.pyramid.progress import SessionProgress
 from .. import SearchableAlchemyGridView, CrudView, View
+from ...progress import SessionProgress
 
 from rattail import enum
 from rattail import batches

tailbone/views/products.py

@@ -35,7 +35,6 @@ from pyramid.httpexceptions import HTTPFound
 from pyramid.renderers import render_to_response
 
 import edbob
-from edbob.pyramid.progress import SessionProgress
 from . import SearchableAlchemyGridView
 
 import rattail.labels
@@ -52,6 +51,7 @@ from rattail.db.api import get_product_by_upc
 from ..db import Session
 from ..forms import GPCFieldRenderer, BrandFieldRenderer, PriceFieldRenderer
 from . import CrudView
+from ..progress import SessionProgress
 
 
 class ProductsGrid(SearchableAlchemyGridView):