sqlobject/sqlobject/inheritance/__init__.py at master · sqlobject/sqlobject · GitHub

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from functools import reduce

from sqlobject import dbconnection

from sqlobject import classregistry

from sqlobject import events

from sqlobject import sqlbuilder

from sqlobject.col import StringCol, ForeignKey

from sqlobject.main import sqlmeta, SQLObject, SelectResults, \

makeProperties, unmakeProperties, getterName, setterName

from sqlobject.compat import string_type

from . import iteration

def tablesUsedSet(obj, db):

if hasattr(obj, "tablesUsedSet"):

return obj.tablesUsedSet(db)

elif isinstance(obj, (tuple, list, set, frozenset)):

s = set()

for component in obj:

s.update(tablesUsedSet(component, db))

return s

else:

return set()

class InheritableSelectResults(SelectResults):

IterationClass = iteration.InheritableIteration

def __init__(self, sourceClass, clause, clauseTables=None,

inheritedTables=None, **ops):

if clause is None or isinstance(clause, str) and clause == 'all':

clause = sqlbuilder.SQLTrueClause

dbName = (ops.get('connection', None)

or sourceClass._connection).dbName

tablesSet = tablesUsedSet(clause, dbName)

tablesSet.add(str(sourceClass.sqlmeta.table))

orderBy = ops.get('orderBy')

if inheritedTables:

for tableName in inheritedTables:

tablesSet.add(str(tableName))

if orderBy and not isinstance(orderBy, string_type):

tablesSet.update(tablesUsedSet(orderBy, dbName))

# DSM: if this class has a parent, we need to link it

# DSM: and be sure the parent is in the table list.

# DSM: The following code is before clauseTables

# DSM: because if the user uses clauseTables

# DSM: (and normal string SELECT), he must know what he wants

# DSM: and will do himself the relationship between classes.

if not isinstance(clause, str):

tableRegistry = {}

allClasses = classregistry.registry(

sourceClass.sqlmeta.registry).allClasses()

for registryClass in allClasses:

if str(registryClass.sqlmeta.table) in tablesSet:

# DSM: By default, no parents are needed for the clauses

tableRegistry[registryClass] = registryClass

tableRegistryCopy = tableRegistry.copy()

for childClass in tableRegistryCopy:

if childClass not in tableRegistry:

continue

currentClass = childClass

while currentClass:

if currentClass in tableRegistryCopy:

if currentClass in tableRegistry:

# DSM: Remove this class as it is a parent one

# DSM: of a needed children

del tableRegistry[currentClass]

# DSM: Must keep the last parent needed

# DSM: (to limit the number of join needed)

tableRegistry[childClass] = currentClass

currentClass = currentClass.sqlmeta.parentClass

# DSM: Table registry contains only the last children

# DSM: or standalone classes

parentClause = []

for (currentClass, minParentClass) in tableRegistry.items():

while (currentClass != minParentClass) \

and currentClass.sqlmeta.parentClass:

parentClass = currentClass.sqlmeta.parentClass

parentClause.append(currentClass.q.id == parentClass.q.id)

currentClass = parentClass

tablesSet.add(str(currentClass.sqlmeta.table))

clause = reduce(sqlbuilder.AND, parentClause, clause)

super(InheritableSelectResults, self).__init__(

sourceClass, clause, clauseTables, **ops)

def accumulateMany(self, *attributes, **kw):

if kw.get("skipInherited"):

return super(InheritableSelectResults, self).\

accumulateMany(*attributes)

tables = []

for func_name, attribute in attributes:

if not isinstance(attribute, string_type):

tables.append(attribute.tableName)

clone = self.__class__(self.sourceClass, self.clause,

self.clauseTables, inheritedTables=tables,

**self.ops)

return clone.accumulateMany(skipInherited=True, *attributes)

class InheritableSQLMeta(sqlmeta):

@classmethod

def addColumn(sqlmeta, columnDef, changeSchema=False, connection=None,

childUpdate=False):

soClass = sqlmeta.soClass

# DSM: Try to add parent properties to the current class

# DSM: Only do this once if possible at object creation and once for

# DSM: each new dynamic column to refresh the current class

if sqlmeta.parentClass:

for col in sqlmeta.parentClass.sqlmeta.columnList:

cname = col.name

if cname == 'childName':

continue

if cname.endswith("ID"):

cname = cname[:-2]

setattr(soClass, getterName(cname), eval(

'lambda self: self._parent.%s' % cname))

if not col.immutable:

def make_setfunc(cname):

def setfunc(self, val):

if not self.sqlmeta._creating and \

not getattr(self.sqlmeta,

"row_update_sig_suppress", False):

self.sqlmeta.send(events.RowUpdateSignal, self,

{cname: val})

setattr(self._parent, cname, val)

return setfunc

setfunc = make_setfunc(cname)

setattr(soClass, setterName(cname), setfunc)

if childUpdate:

makeProperties(soClass)

return

if columnDef:

super(InheritableSQLMeta, sqlmeta).addColumn(columnDef,

changeSchema,

connection)

# DSM: Update each child class if needed and existing (only for new

# DSM: dynamic column as no child classes exists at object creation)

if columnDef and hasattr(soClass, "q"):

q = getattr(soClass.q, columnDef.name, None)

else:

q = None

for c in sqlmeta.childClasses.values():

c.sqlmeta.addColumn(columnDef, connection=connection,

childUpdate=True)

if q:

setattr(c.q, columnDef.name, q)

@classmethod

def delColumn(sqlmeta, column, changeSchema=False, connection=None,

childUpdate=False):

if childUpdate:

soClass = sqlmeta.soClass

unmakeProperties(soClass)

makeProperties(soClass)

if isinstance(column, str):

name = column

else:

name = column.name

delattr(soClass, name)

delattr(soClass.q, name)

return

super(InheritableSQLMeta, sqlmeta).delColumn(column, changeSchema,

connection)

# DSM: Update each child class if needed

# DSM: and delete properties for this column

for c in sqlmeta.childClasses.values():

c.sqlmeta.delColumn(column, changeSchema=changeSchema,

connection=connection, childUpdate=True)

@classmethod

def addJoin(sqlmeta, joinDef, childUpdate=False):

soClass = sqlmeta.soClass

# DSM: Try to add parent properties to the current class

# DSM: Only do this once if possible at object creation and once for

# DSM: each new dynamic join to refresh the current class

if sqlmeta.parentClass:

for join in sqlmeta.parentClass.sqlmeta.joins:

jname = join.joinMethodName

jarn = join.addRemoveName

setattr(

soClass, getterName(jname),

eval('lambda self: self._parent.%s' % jname))

if hasattr(join, 'remove'):

setattr(

soClass, 'remove' + jarn,

eval('lambda self,o: self._parent.remove%s(o)' % jarn))

if hasattr(join, 'add'):

setattr(

soClass, 'add' + jarn,

eval('lambda self,o: self._parent.add%s(o)' % jarn))

if childUpdate:

makeProperties(soClass)

return

if joinDef:

super(InheritableSQLMeta, sqlmeta).addJoin(joinDef)

# DSM: Update each child class if needed and existing (only for new

# DSM: dynamic join as no child classes exists at object creation)

for c in sqlmeta.childClasses.values():

c.sqlmeta.addJoin(joinDef, childUpdate=True)

@classmethod

def delJoin(sqlmeta, joinDef, childUpdate=False):

if childUpdate:

soClass = sqlmeta.soClass

unmakeProperties(soClass)

makeProperties(soClass)

return

super(InheritableSQLMeta, sqlmeta).delJoin(joinDef)

# DSM: Update each child class if needed

# DSM: and delete properties for this join

for c in sqlmeta.childClasses.values():

c.sqlmeta.delJoin(joinDef, childUpdate=True)

@classmethod

def getAllColumns(sqlmeta):

columns = sqlmeta.columns.copy()

sm = sqlmeta

while sm.parentClass:

columns.update(sm.parentClass.sqlmeta.columns)

sm = sm.parentClass.sqlmeta

return columns

@classmethod

def getColumns(sqlmeta):

columns = sqlmeta.getAllColumns()

if 'childName' in columns:

del columns['childName']

return columns

class InheritableSQLObject(SQLObject):

sqlmeta = InheritableSQLMeta

_inheritable = True

SelectResultsClass = InheritableSelectResults

def set(self, **kw):

if self._parent:

SQLObject.set(self, _suppress_set_sig=True, **kw)

else:

SQLObject.set(self, **kw)

def __classinit__(cls, new_attrs):

SQLObject.__classinit__(cls, new_attrs)

# if we are a child class, add sqlbuilder fields from parents

currentClass = cls.sqlmeta.parentClass

while currentClass:

for column in currentClass.sqlmeta.columnDefinitions.values():

if column.name == 'childName':

continue

if isinstance(column, ForeignKey):

continue

setattr(cls.q, column.name,

getattr(currentClass.q, column.name))

currentClass = currentClass.sqlmeta.parentClass

@classmethod

def _SO_setupSqlmeta(cls, new_attrs, is_base):

# Note: cannot use super(InheritableSQLObject, cls)._SO_setupSqlmeta -

# InheritableSQLObject is not defined when it's __classinit__

# is run. Cannot use SQLObject._SO_setupSqlmeta, either:

# the method would be bound to wrong class.

if cls.__name__ == "InheritableSQLObject":

call_super = super(cls, cls)

else:

# InheritableSQLObject must be in globals yet

call_super = super(InheritableSQLObject, cls)

call_super._SO_setupSqlmeta(new_attrs, is_base)

sqlmeta = cls.sqlmeta

sqlmeta.childClasses = {}

# locate parent class and register this class in it's children

sqlmeta.parentClass = None

for superclass in cls.__bases__:

if getattr(superclass, '_inheritable', False) \

and (superclass.__name__ != 'InheritableSQLObject'):

if sqlmeta.parentClass:

# already have a parent class;

# cannot inherit from more than one

raise NotImplementedError(

"Multiple inheritance is not implemented")

sqlmeta.parentClass = superclass

superclass.sqlmeta.childClasses[cls.__name__] = cls

if sqlmeta.parentClass:

# remove inherited column definitions

cls.sqlmeta.columns = {}

cls.sqlmeta.columnList = []

cls.sqlmeta.columnDefinitions = {}

# default inheritance child name

if not sqlmeta.childName:

sqlmeta.childName = cls.__name__

@classmethod

def get(cls, id, connection=None, selectResults=None,

childResults=None, childUpdate=False):

val = super(InheritableSQLObject, cls).get(id, connection,

selectResults)

# DSM: If we are updating a child, we should never return a child...

if childUpdate:

return val

# DSM: If this class has a child, return the child

if 'childName' in cls.sqlmeta.columns:

childName = val.childName

if childName is not None:

childClass = cls.sqlmeta.childClasses[childName]

# If the class has no columns (which sometimes makes sense

# and may be true for non-inheritable (leaf) classes only),

# shunt the query to avoid almost meaningless SQL

# like "SELECT NULL FROM child WHERE id=1".

# This is based on assumption that child object exists

# if parent object exists. (If it doesn't your database

# is broken and that is a job for database maintenance.)

if not (childResults or childClass.sqlmeta.columns):

childResults = (None,)

return childClass.get(id, connection=connection,

selectResults=childResults)

# DSM: Now, we know we are alone or the last child in a family...

# DSM: It's time to find our parents

inst = val

while inst.sqlmeta.parentClass and not inst._parent:

inst._parent = inst.sqlmeta.parentClass.get(

id, connection=connection, childUpdate=True)

inst = inst._parent

# DSM: We can now return ourself

return val

@classmethod

def _notifyFinishClassCreation(cls):

sqlmeta = cls.sqlmeta

# verify names of added columns

if sqlmeta.parentClass:

# FIXME: this does not check for grandparent column overrides

parentCols = sqlmeta.parentClass.sqlmeta.columns.keys()

for column in sqlmeta.columnList:

if column.name == 'childName':

raise AttributeError(

"The column name 'childName' is reserved")

if column.name in parentCols:

raise AttributeError(

"The column '%s' is already defined "

"in an inheritable parent" % column.name)

# if this class is inheritable, add column for children distinction

if cls._inheritable and (cls.__name__ != 'InheritableSQLObject'):

sqlmeta.addColumn(

StringCol(name='childName',

# limit string length to get VARCHAR and not CLOB

length=255, default=None))

if not sqlmeta.columnList:

# There are no columns - call addColumn to propagate columns

# from parent classes to children

sqlmeta.addColumn(None)

if not sqlmeta.joins:

# There are no joins - call addJoin to propagate joins

# from parent classes to children

sqlmeta.addJoin(None)

def _create(self, id, **kw):

# DSM: If we were called by a children class,

# DSM: we must retreive the properties dictionary.

# DSM: Note: we can't use the ** call paremeter directly

# DSM: as we must be able to delete items from the dictionary

# DSM: (and our children must know that the items were removed!)

if 'kw' in kw:

kw = kw['kw']

# DSM: If we are the children of an inheritable class,

# DSM: we must first create our parent

if self.sqlmeta.parentClass:

parentClass = self.sqlmeta.parentClass

new_kw = {}

parent_kw = {}

for (name, value) in kw.items():

if (name != 'childName') and hasattr(parentClass, name):

parent_kw[name] = value

else:

new_kw[name] = value

kw = new_kw

# Need to check that we have enough data to sucesfully

# create the current subclass otherwise we will leave

# the database in an inconsistent state.

for col in self.sqlmeta.columnList:

if (col._default == sqlbuilder.NoDefault) and \

(col.name not in kw) and (col.foreignName not in kw):

raise TypeError(

"%s() did not get expected keyword argument "

"%s" % (self.__class__.__name__, col.name))

parent_kw['childName'] = self.sqlmeta.childName

self._parent = parentClass(kw=parent_kw,

connection=self._connection)

id = self._parent.id

# TC: Create this record and catch all exceptions in order to destroy

# TC: the parent if the child can not be created.

try:

super(InheritableSQLObject, self)._create(id, **kw)

except Exception:

# If we are outside a transaction and this is a child,

# destroy the parent

connection = self._connection

if (not isinstance(connection, dbconnection.Transaction)

and connection.autoCommit) and self.sqlmeta.parentClass:

self._parent.destroySelf()

# TC: Do we need to do this??

self._parent = None

# TC: Reraise the original exception

raise

@classmethod

def _findAlternateID(cls, name, dbName, value, connection=None):

result = list(cls.selectBy(connection, **{name: value}))

if not result:

return result, None

obj = result[0]

return [obj.id], obj

@classmethod

def select(cls, clause=None, *args, **kwargs):

parentClass = cls.sqlmeta.parentClass

childUpdate = kwargs.pop('childUpdate', None)

# childUpdate may have one of three values:

# True:

# select was issued by parent class to create child objects.

# Execute select without modifications.

# None (default):

# select is run by application. If this class is inheritance

# child, delegate query to the parent class to utilize

# InheritableIteration optimizations. Selected records

# are restricted to this (child) class by adding childName

# filter to the where clause.

# False:

# select is delegated from inheritance child which is parent

# of another class. Delegate the query to parent if possible,

# but don't add childName restriction: selected records

# will be filtered by join to the table filtered by childName.

if (not childUpdate) and parentClass:

if childUpdate is None:

# this is the first parent in deep hierarchy

addClause = parentClass.q.childName == cls.sqlmeta.childName

# if the clause was one of TRUE varians, replace it

if (clause is None) or (clause is sqlbuilder.SQLTrueClause) \

or (

isinstance(clause, string_type)

and (clause == 'all')):

clause = addClause

else:

# patch WHERE condition:

# change ID field of this class to ID of parent class

# XXX the clause is patched in place; it would be better

# to build a new one if we have to replace field

clsID = cls.q.id

parentID = parentClass.q.id

def _get_patched(clause):

if isinstance(clause, sqlbuilder.SQLOp):

_patch_id_clause(clause)

return None

elif not isinstance(clause, sqlbuilder.Field):

return None

elif (clause.tableName == clsID.tableName) \

and (clause.fieldName == clsID.fieldName):

return parentID

else:

return None

def _patch_id_clause(clause):

if not isinstance(clause, sqlbuilder.SQLOp):

return

expr = _get_patched(clause.expr1)

if expr:

clause.expr1 = expr

expr = _get_patched(clause.expr2)

if expr:

clause.expr2 = expr

_patch_id_clause(clause)

# add childName filter

clause = sqlbuilder.AND(clause, addClause)

return parentClass.select(clause, childUpdate=False,

*args, **kwargs)

else:

return super(InheritableSQLObject, cls).select(

clause, *args, **kwargs)

@classmethod

def selectBy(cls, connection=None, **kw):

clause = []

foreignColumns = {}

currentClass = cls

while currentClass:

foreignColumns.update(dict(

[(column.foreignName, name)

for (name, column) in currentClass.sqlmeta.columns.items()

if column.foreignKey

]))

currentClass = currentClass.sqlmeta.parentClass

for name, value in kw.items():

if name in foreignColumns:

name = foreignColumns[name] # translate "key" to "keyID"

if isinstance(value, SQLObject):

value = value.id

currentClass = cls

while currentClass:

try:

clause.append(getattr(currentClass.q, name) == value)

break

except AttributeError:

pass

currentClass = currentClass.sqlmeta.parentClass

else:

raise AttributeError(

"'%s' instance has no attribute '%s'" % (

cls.__name__, name))

if clause:

clause = reduce(sqlbuilder.AND, clause)

else:

clause = None # select all

conn = connection or cls._connection

return cls.SelectResultsClass(cls, clause, connection=conn)

def destroySelf(self):

# DSM: If this object has parents, recursivly kill them

if hasattr(self, '_parent') and self._parent:

self._parent.destroySelf()

super(InheritableSQLObject, self).destroySelf()

def _reprItems(self):

items = super(InheritableSQLObject, self)._reprItems()

# add parent attributes (if any)

if self.sqlmeta.parentClass:

items.extend(self._parent._reprItems())

# filter out our special column

return [item for item in items if item[0] != 'childName']

__all__ = ['InheritableSQLObject']

sqlobject/sqlobject/inheritance/init.py at master · sqlobject/sqlobject · GitHub

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sqlobject/sqlobject/inheritance/__init__.py at master · sqlobject/sqlobject · GitHub

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sqlobject/sqlobject/inheritance/init.py at master · sqlobject/sqlobject · GitHub

init.py

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