From 67894aa8d91210a8f85d08d02e7e656497795c24 Mon Sep 17 00:00:00 2001
From: Tim Bentley <tim.bentley@gmail.com>
Date: Sat, 27 Aug 2011 19:43:05 +0100
Subject: [PATCH] Error Handling improvements

---
 openlp/core/lib/db.py                   | 34 +++++++++++++++----------
 openlp/plugins/songs/lib/upgrade.py     | 21 +++++++--------
 openlp/plugins/songusage/lib/upgrade.py |  9 +++----
 3 files changed, 33 insertions(+), 31 deletions(-)

diff --git a/openlp/core/lib/db.py b/openlp/core/lib/db.py
index 176262b22..2e5d011cf 100644
--- a/openlp/core/lib/db.py
+++ b/openlp/core/lib/db.py
@@ -79,8 +79,11 @@ def upgrade_db(url, upgrade):
         Provides a class for the metadata table.
         """
         pass
-
-    tables = upgrade.upgrade_setup(metadata)
+    load_changes = True
+    try:
+        tables = upgrade.upgrade_setup(metadata)
+    except SQLAlchemyError, DBAPIError:
+        load_changes = False
     metadata_table = Table(u'metadata', metadata,
         Column(u'key', types.Unicode(64), primary_key=True),
         Column(u'value', types.UnicodeText(), default=None)
@@ -90,22 +93,27 @@ def upgrade_db(url, upgrade):
     version_meta = session.query(Metadata).get(u'version')
     if version_meta is None:
         version_meta = Metadata.populate(key=u'version', value=u'0')
-        version = 0 if tables else upgrade.__version__;
+        version = 0
     else:
         version = int(version_meta.value)
     if version > upgrade.__version__:
         return version, upgrade.__version__
     version += 1
-    while hasattr(upgrade, u'upgrade_%d' % version):
-        log.debug(u'Running upgrade_%d', version)
-        try:
-            getattr(upgrade, u'upgrade_%d' % version)(session, metadata, tables)
-            version_meta.value = unicode(version)
-        except SQLAlchemyError, DBAPIError:
-            log.exception(u'Could not run database upgrade script "upgrade_%s"'\
-                ', upgrade process has been halted.', version)
-            break
-        version += 1
+    if load_changes:
+        while hasattr(upgrade, u'upgrade_%d' % version):
+            log.debug(u'Running upgrade_%d', version)
+            try:
+                getattr(upgrade, u'upgrade_%d' % version) \
+                    (session, metadata, tables)
+                version_meta.value = unicode(version)
+            except SQLAlchemyError, DBAPIError:
+                log.exception(u'Could not run database upgrade script '
+                    '"upgrade_%s", upgrade process has been halted.', version)
+                break
+            version += 1
+    else:
+        version_meta = Metadata.populate(key=u'version',
+            value=int(upgrade.__version__))
     session.add(version_meta)
     session.commit()
     return int(version_meta.value), upgrade.__version__
diff --git a/openlp/plugins/songs/lib/upgrade.py b/openlp/plugins/songs/lib/upgrade.py
index b28d1764d..fae3400c2 100644
--- a/openlp/plugins/songs/lib/upgrade.py
+++ b/openlp/plugins/songs/lib/upgrade.py
@@ -42,18 +42,15 @@ def upgrade_setup(metadata):
     upgrade process. If you want to drop a table, you need to remove it from
     here, and add it to your upgrade function.
     """
-    try:
-        tables = {
-            u'authors': Table(u'authors', metadata, autoload=True),
-            u'media_files': Table(u'media_files', metadata, autoload=True),
-            u'song_books': Table(u'song_books', metadata, autoload=True),
-            u'songs': Table(u'songs', metadata, autoload=True),
-            u'topics': Table(u'topics', metadata, autoload=True),
-            u'authors_songs': Table(u'authors_songs', metadata, autoload=True),
-            u'songs_topics': Table(u'songs_topics', metadata, autoload=True)
-        }
-    except:
-        tables = None
+    tables = {
+        u'authors': Table(u'authors', metadata, autoload=True),
+        u'media_files': Table(u'media_files', metadata, autoload=True),
+        u'song_books': Table(u'song_books', metadata, autoload=True),
+        u'songs': Table(u'songs', metadata, autoload=True),
+        u'topics': Table(u'topics', metadata, autoload=True),
+        u'authors_songs': Table(u'authors_songs', metadata, autoload=True),
+        u'songs_topics': Table(u'songs_topics', metadata, autoload=True)
+    }
     return tables
 
 
diff --git a/openlp/plugins/songusage/lib/upgrade.py b/openlp/plugins/songusage/lib/upgrade.py
index d4211a038..50ca32fcd 100644
--- a/openlp/plugins/songusage/lib/upgrade.py
+++ b/openlp/plugins/songusage/lib/upgrade.py
@@ -40,12 +40,9 @@ def upgrade_setup(metadata):
     upgrade process. If you want to drop a table, you need to remove it from
     here, and add it to your upgrade function.
     """
-    try:
-        tables = {
-            u'songusage_data': Table(u'songusage_data', metadata, autoload=True)
-        }
-    except:
-        tables = None
+    tables = {
+        u'songusage_data': Table(u'songusage_data', metadata, autoload=True)
+    }
     return tables