[#12] Ajout du module fields_types

EditorialModel/fields_types.py

@@ -0,0 +1,91 @@
+#-*- coding: utf-8 -*-
+
+from EditorialModel.fields import EmField
+from EditorialModel.types import EmType
+from EditorialModel.fieldtypes import EmField_integer
+
+from Database import sqlutils
+import sqlalchemy as sqla
+
+import logging
+
+logger = logging.getLogger('Lodel2.EditorialModel')
+
+## Em_Field_Type (Class)
+#
+# Represents an association between a field and a type
+class Em_Field_Type(object):
+
+    table = 'em_field_type'
+    _fields = [('type_id', EmField_integer()),('field_id', EmField_integer())]
+    dbconf = 'default'
+
+    ## __init__ (Function)
+    #
+    # Instanciates an Em_Field_Type object with data fetched from the database
+    #
+    # @param type_id integer: Identifier of the type
+    # @param field_id integer: Identifier of the field
+    def __init__(self, type_id, field_id):
+        self.table = Em_Field_Type.table
+        self._fields = self.__class__._fields
+        self.type_id = type_id
+        self.field_id = field_id
+
+    ## GetDbe (Function)
+    #
+    # Returns the sqlAlchemy engine
+    @classmethod
+    def getDbe(cls):
+        return sqlutils.getEngine(cls.dbconf)
+
+    ## Create (Function)
+    #
+    # Creates a relation between a field and a type
+    #
+    # @static
+    #
+    # @param emType EmType: Object representing the Type
+    # @param emField EmField: Object representing the Field
+    # @return Em_Field_Type object
+    @classmethod
+    def create(cls, emType, emField):
+        values = {
+                'type_id': emType.uid,
+                'field_id': emField.uid
+        }
+
+        createdRelation = Em_Field_Type._createDb(**values)
+        return createdRelation
+
+    @classmethod
+    def _createDb(cls, **kwargs):
+        dbe = cls.getDbe()
+        conn = dbe.connect()
+        table = sqla.Table(cls.table, sqlutils.meta(dbe))
+        req = table.insert(kwargs)
+        res = conn.execute(req)
+        conn.close()
+        return Em_Field_Type(kwargs['type_id'], kwargs['field_id'])
+
+    ## Exists (Function)
+    #
+    # Checks if a the relation exists in the database
+    #
+    # @return True if success, False if failure
+    def exists(self):
+        return _existsDb()
+
+    ## _ExistsDb (Function)
+    #
+    # Queries the database to see if a relation exists or not
+    #
+    # @return True if success, False if failure
+    def _existsDb(self):
+        dbe = self.getDbe()
+        table = sqla.Table(self.table, sqlutils.meta(dbe))
+        req = table.Select().Where(table.c.type_id==self.type_id).Where(table.c.field_id==self.field_id)
+        conn = dbe.connect()
+        res = conn.execute(req).fetchall()
+        conn.close()
+        return len(res)>0