From b45e7ea4ee7703b8316fa6f855585959de07d264 Mon Sep 17 00:00:00 2001
From: Yann <yann.weber@openedition.org>
Date: Fri, 19 Jun 2015 16:12:40 +0200
Subject: [PATCH] Added an getTable function to sqlutils

It takes an EmComponent child class as parameter and return an sqlalchemy Table
---
 Database/sqlutils.py | 110 +++++++++++++++++++++++++------------------
 1 file changed, 65 insertions(+), 45 deletions(-)

diff --git a/Database/sqlutils.py b/Database/sqlutils.py
index 0945eff..f367472 100644
--- a/Database/sqlutils.py
+++ b/Database/sqlutils.py
@@ -10,64 +10,84 @@ from django.conf import settings
 os.environ.setdefault("DJANGO_SETTINGS_MODULE", "Lodel.settings")
 
 ENGINES = {'mysql': {
-				'driver': 'pymysql',
-				'encoding': 'utf8'
-			},
-			'postgresql': {
-				'driver': 'psycopg2',
-				'encoding': 'utf8',
-			},
-			'sqlite': {
-				'driver': 'pysqlite',
-				'encoding': 'utf8',
-			},
+                'driver': 'pymysql',
+                'encoding': 'utf8'
+            },
+            'postgresql': {
+                'driver': 'psycopg2',
+                'encoding': 'utf8',
+            },
+            'sqlite': {
+                'driver': 'pysqlite',
+                'encoding': 'utf8',
+            },
 }
 
 sqlcfg = settings.LODEL2SQLWRAPPER
 
+## Return an engine given a dbconf name
+# @param ename str: Its a name of an item in django.conf.settings.LODEL2SQLWRAPPER['db']
+# @param sqlalogging None|bool : If None leave default value, if true activate sqlalchemy logging
+# @return An sqlalchemy engine
 def getEngine(ename = 'default', sqlalogging = None):
-	""" Return a sqlalchemy engine
-		@param read bool: If True return the read engine, else 
-		return the write one
-		@return a sqlachemy engine instance
+    """ Return a sqlalchemy engine
+        @param read bool: If True return the read engine, else 
+        return the write one
+        @return a sqlachemy engine instance
 
-		@todo Put the check on db config in SqlWrapper.checkConf()
-	"""
-	#Loading confs
-	cfg = sqlcfg['db'][ename]
+        @todo Put the check on db config in SqlWrapper.checkConf()
+    """
+    #Loading confs
+    cfg = sqlcfg['db'][ename]
 
-	edata = ENGINES[cfg['ENGINE']] #engine infos
-	conn_str = ""
+    edata = ENGINES[cfg['ENGINE']] #engine infos
+    conn_str = ""
 
-	if cfg['ENGINE'] == 'sqlite':
-		#Sqlite connection string
-		conn_str = '%s+%s:///%s'%( cfg['ENGINE'],
-			edata['driver'],
-			cfg['NAME'])
-	else:
-		#Mysql and Postgres connection string
-		user = cfg['USER']
-		user += (':'+cfg['PASSWORD'] if 'PASSWORD' in cfg else '')
-		
-		if 'HOST' not in cfg:
-			logger.info('Not HOST in configuration, using localhost')
-			host = 'localhost'
-		else:
-			host = cfg['HOST']
+    if cfg['ENGINE'] == 'sqlite':
+        #Sqlite connection string
+        conn_str = '%s+%s:///%s'%( cfg['ENGINE'],
+            edata['driver'],
+            cfg['NAME'])
+    else:
+        #Mysql and Postgres connection string
+        user = cfg['USER']
+        user += (':'+cfg['PASSWORD'] if 'PASSWORD' in cfg else '')
+        
+        if 'HOST' not in cfg:
+            logger.info('Not HOST in configuration, using localhost')
+            host = 'localhost'
+        else:
+            host = cfg['HOST']
 
-		host += (':'+cfg['PORT'] if 'PORT' in cfg else '')
+        host += (':'+cfg['PORT'] if 'PORT' in cfg else '')
 
-		conn_str = '%s+%s://'%(cfg['ENGINE'], edata['driver'])
-		conn_str += '%s@%s/%s'%(user,host,cfg['NAME'])
+        conn_str = '%s+%s://'%(cfg['ENGINE'], edata['driver'])
+        conn_str += '%s@%s/%s'%(user,host,cfg['NAME'])
 
 
-	ret = sqla.create_engine(conn_str, encoding=edata['encoding'], echo=sqlalogging)
+    ret = sqla.create_engine(conn_str, encoding=edata['encoding'], echo=sqlalogging)
 
-	logger.debug("Getting engine :"+str(ret))
+    logger.debug("Getting engine :"+str(ret))
 
-	return ret
+    return ret
 
+## Return a sqlalchemy.MetaData object
+# @param engine sqlalchemy.engine : A sqlalchemy engine
+# @return an sql alechemy MetaData instance bind to engine
 def meta(engine):
-		res = sqla.MetaData()
-		res.reflect(bind=engine)
-		return res
+    res = sqla.MetaData()
+    res.reflect(bind=engine)
+    return res
+
+## Return an sqlalchemy table given an EmComponent child class
+# @warning Except a class type not an instance
+# @param em_class : An EmComponent child class
+# @return An sqlalchemy table
+# @throw TypeError if em_instance is an EmComponent  or not an EmComponent child class (or an instance)
+def getTable(cls):
+    from EditorialModel.components import EmComponent #dirty circula inclusion hack
+    if not issubclass(cls, EmComponent) or cls.table == None:
+        raise TypeError("Excepting an EmComponent child class not an "+str(cls))
+    engine = cls.getDbE()
+    return sqla.Table(cls.table, meta(engine))
+