From 26d0150161351857bb1942e82620514119e0296c 2013-02-25 15:27:49
From: Lance Edgar <lance@edbob.org>
Date: 2013-02-25 15:27:49
Subject: [PATCH] Added ``wince`` module.

This module is used to interface with the Rattail app for Windows CE handheld
devices.

---

diff --git a/rattail/wince.py b/rattail/wince.py
new file mode 100644
index 0000000000000000000000000000000000000000..79fa033f0fa48d4d9cd2c78245e8cb0a9c70dcbe
--- /dev/null
+++ b/rattail/wince.py
@@ -0,0 +1,132 @@
+#!/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/>.
+#
+################################################################################
+
+"""
+``rattail.wince`` -- Windows CE App Interface
+"""
+
+import os
+import os.path
+
+import edbob
+
+from rattail import files
+from rattail.csvutil import DictWriter
+
+
+def collect_batch(path, device='Default'):
+    """
+    This function is meant to be invoked by the file monitor.  Its purpose is
+    to gather handheld scan batch files from arbitrary device-specific folders,
+    and move them to yet another ("upstream") folder so that they may be part
+    of a single processing queue.  Rather than moving the file as-is, the
+    following processing is done on the file:
+
+    Since the Rattail CE app saves the batch contents using a somewhat "binary"
+    format, the raw file is parsed (with :func:`parse_batch_file()`) and a
+    proper CSV file is written with the "translated" contents.  This file is
+    then copied to the collection folder.
+
+    The filename used for the final destination path is also manipulated.
+    Instead of using the original filename, one is generated which contains the
+    original filename, plus the "device name" and the timestamp of the original
+    file.  The ``device`` parameter is used to determine the device name.
+    """
+
+    queue = edbob.config.require('rattail.wince', 'collection_dir')
+    ctime = files.creation_time(path)
+    final_path = os.path.join(queue, '%s,%s,%s.csv' % (
+            device,
+            ctime.strftime('%Y-%m-%d %H-%M-%S'),
+            os.path.basename(path)))
+
+    csv_path = edbob.temp_path(prefix='rattail.', suffix='.csv')
+    csv_file = open(csv_path, 'wb')
+    writer = DictWriter(csv_file, ['upc', 'cases', 'units'])
+    writer.writeheader()
+    for upc, cases, units in parse_batch_file(path):
+        writer.writerow({
+                'upc': upc,
+                'cases': cases,
+                'units': units,
+                })
+    csv_file.close()
+
+    files.locking_copy(csv_path, final_path)
+
+
+def parse_batch_file(path, progress=None):
+    """
+    Generator which parses a scan batch file originating from the Rattail CE
+    application.
+
+    When a valid record is encountered, it is returned as a tuple of the form
+    ``(scancode, cases, units)``.
+    """
+
+    scancode = None
+    cases = None
+    units = None
+
+    prog = None
+    if progress:
+        prog = progress("Parsing scan batch file", files.count_lines(path))
+
+    i = 1
+    f = open(path, 'rb')
+    line = f.readline()
+    while len(line):
+        line = line.replace('\x00', '')
+        line = line.rstrip('\n')
+        
+        if scancode is None:
+            scancode = line
+
+        elif cases is None:
+            line = line.strip()
+            if line and line.isdigit():
+                cases = int(line)
+            else:
+                cases = 0
+
+        elif units is None:
+            line = line.strip()
+            if line and line.isdigit():
+                units = int(line)
+            else:
+                units = 0
+
+            yield scancode, cases, units
+            scancode = None
+            cases = None
+            units = None
+
+        if prog:
+            prog.update(i)
+        i += 1
+        line = f.readline()
+
+    f.close()
+    if prog:
+        prog.destroy()