Python django south和django审计日志

我试图对现有的应用程序进行修改，以添加到其中（跟踪用户发起的模块更改），但遇到了重大错误。特别是action_user_id字段，它是LastUserField（存储指定要跟踪的更改的用户）

如果我从空白模型开始，我可以通过以下方式添加审核日志：

from audit_log.models.managers import AuditLog
...
class SomeModel(models.Model)
    ...
    audit_log = AuditLog()

应用这个简单的更改并在django south执行schemamigration很容易理解，这给了我一个错误：

 ! Cannot freeze field 'myapp.mymodelauditlogentry.action_user'
 ! (this field has class audit_log.models.fields.LastUserField)

 ! South cannot introspect some fields; this is probably because they are custom
 ! fields. If they worked in 0.6 or below, this is because we have removed the
 ! models parser (it often broke things).
 ! To fix this, read http://south.aeracode.org/wiki/MyFieldsDontWork

我阅读了myfieldsdontworkwiki（以及自定义字段/内省部分），但并不100%清楚我需要做什么才能让字段正常工作

我尝试添加：

from south.modelsinspector import add_introspection_rules
add_introspection_rules([], ["^audit_log\.models\.fields\.LastUserField"])

我的models.py允许./manage.py模式迁移创建迁移脚本，而前面的错误消失了。但是，当我尝试迁移（应用迁移）时，会出现以下错误：

Running migrations for myapp:
 - Migrating forwards to 0004_auto__add_mymodelauditlogentry.
 > my_app:0004_auto__add_mymodelauditlogentry
Traceback (most recent call last):
  File "./manage.py", line 11, in <module>
    execute_manager(settings)
      File "/usr/local/lib/python2.6/dist-packages/Django-1.2.3-py2.6.egg/django/core/management/__init__.py", line 438, in execute_manager
    utility.execute()
  File "/usr/local/lib/python2.6/dist-packages/Django-1.2.3-py2.6.egg/django/core/management/__init__.py", line 379, in execute
    self.fetch_command(subcommand).run_from_argv(self.argv)
  File "/usr/local/lib/python2.6/dist-packages/Django-1.2.3-py2.6.egg/django/core/management/base.py", line 191, in run_from_argv
    self.execute(*args, **options.__dict__)
  File "/usr/local/lib/python2.6/dist-packages/Django-1.2.3-py2.6.egg/django/core/management/base.py", line 220, in execute
    output = self.handle(*args, **options)
  File "/usr/local/lib/python2.6/dist-packages/South-0.7.3-py2.6.egg/south/management/commands/migrate.py", line 105, in handle
    ignore_ghosts = ignore_ghosts,
  File "/usr/local/lib/python2.6/dist-packages/South-0.7.3-py2.6.egg/south/migration/__init__.py", line 191, in migrate_app
    success = migrator.migrate_many(target, workplan, database)
  File "/usr/local/lib/python2.6/dist-packages/South-0.7.3-py2.6.egg/south/migration/migrators.py", line 221, in migrate_many
    result = migrator.__class__.migrate_many(migrator, target, migrations, database)
  File "/usr/local/lib/python2.6/dist-packages/South-0.7.3-py2.6.egg/south/migration/migrators.py", line 292, in migrate_many
    result = self.migrate(migration, database)
  File "/usr/local/lib/python2.6/dist-packages/South-0.7.3-py2.6.egg/south/migration/migrators.py", line 125, in migrate
    result = self.run(migration)
  File "/usr/local/lib/python2.6/dist-packages/South-0.7.3-py2.6.egg/south/migration/migrators.py", line 93, in run
    south.db.db.current_orm = self.orm(migration)
  File "/usr/local/lib/python2.6/dist-packages/South-0.7.3-py2.6.egg/south/migration/migrators.py", line 246, in orm
    return migration.orm()
  File "/usr/local/lib/python2.6/dist-packages/South-0.7.3-py2.6.egg/south/utils.py", line 62, in method
    value = function(self)
  File "/usr/local/lib/python2.6/dist-packages/South-0.7.3-py2.6.egg/south/migration/base.py", line 422, in orm
    return FakeORM(self.migration_class(), self.app_label())
  File "/usr/local/lib/python2.6/dist-packages/South-0.7.3-py2.6.egg/south/orm.py", line 46, in FakeORM
    _orm_cache[args] = _FakeORM(*args)  
  File "/usr/local/lib/python2.6/dist-packages/South-0.7.3-py2.6.egg/south/orm.py", line 125, in __init__
    self.models[name] = self.make_model(app_label, model_name, data)
  File "/usr/local/lib/python2.6/dist-packages/South-0.7.3-py2.6.egg/south/orm.py", line 318, in make_model
    field = self.eval_in_context(code, app, extra_imports)
  File "/usr/local/lib/python2.6/dist-packages/South-0.7.3-py2.6.egg/south/orm.py", line 236, in eval_in_context
    return eval(code, globals(), fake_locals)
  File "<string>", line 1, in <module>
  File "/usr/local/lib/python2.6/dist-packages/django_audit_log-0.2.1-py2.6.egg/audit_log/models/fields.py", line 12, in __init__
    super(LastUserField, self).__init__(User, null = True, **kwargs)
TypeError: __init__() got multiple values for keyword argument 'null'

除此之外，审核日志中间件不起作用，因为myapp\u mymodelauditlogentry中没有通过“id”引用“auth\u user”的action\u user\u id整数字段。然后我手动应用SQL（sqlite语法；通过在新创建的数据库上使用sqliteman获得）

它是有效的。如果有人解释我应该如何在django south的环境中通过迁移/内省做到这一点，而不必使用原始的依赖于数据库的SQL，我仍然会给予奖励

此外，我还为action_user_id创建了一个索引

CREATE INDEX "myapp_mymodelauditlogentry_26679921" ON "myapp_mymodelauditlogentry" ("action_user_id")

我发现散列26679921是基于具有

“%x%”（abs（散列（（'action\u user\u id'））%4294967296L，）

的字段名创建的，而不是基于任何其他内容（因此应该始终是_26679921，除非数据库要求使用长名称）。我不确定索引的名称是否重要；但我希望安全。

这是最后的答案（和解释）

向南迁移时，不仅存储模型中字段的名称，还存储传递给它的类型和参数。这样做的结果是，South必须了解哪些参数由字段给出，哪些参数应该存储

因此，当您创建这样的规则时：

add_introspection_rules([], ["^audit_log\.models\.fields\.LastUserField"])

(
  'action_user',
  self.gf('audit_log.models.fields.LastUserField')(
    related_name='_somemodel_audit_log_entry',
    null=True,
    to=orm['auth.User'],
  )
),

rules = [(                                          
    (fields.LastUserField,),                        
    [],                                             
    {                                               
        'to': ['rel.to', {'default': User}],        
        'null': ['null', {'default': True}],        
    },                                              
)]   
add_introspection_rules(                           
    rules,                                         
    ['^audit_log\.models\.fields\.LastUserField'], 
)       

Than South将创建一个具有如下列的表：

add_introspection_rules([], ["^audit_log\.models\.fields\.LastUserField"])

(
  'action_user',
  self.gf('audit_log.models.fields.LastUserField')(
    related_name='_somemodel_audit_log_entry',
    null=True,
    to=orm['auth.User'],
  )
),

rules = [(                                          
    (fields.LastUserField,),                        
    [],                                             
    {                                               
        'to': ['rel.to', {'default': User}],        
        'null': ['null', {'default': True}],        
    },                                              
)]   
add_introspection_rules(                           
    rules,                                         
    ['^audit_log\.models\.fields\.LastUserField'], 
)       

您可以看到，它有一个

相关的\u name

参数、一个

null

参数和一个

to

参数。现在让我们来看一下字段定义：

class LastUserField(models.ForeignKey):                                      
    """                                                                      
    A field that keeps the last user that saved an instance                  
    of a model. None will be the value for AnonymousUser.                    
    """                                                                      

    def __init__(self, **kwargs):                                            
        models.ForeignKey.__init__(self, User, null=True, **kwargs)          
        #print kwargs                                                        
        #super(LastUserField, self).__init__(User, null = True, **kwargs)    

    def contribute_to_class(self, cls, name):                                
        super(LastUserField, self).contribute_to_class(cls, name)            
        registry = registration.FieldRegistry(self.__class__)                
        registry.add_field(cls, self)                                        

我们在这里看到了什么？

ForeignKey

的第一个参数是user（第一个参数是

to

属性）。第二个参数（也是硬编码的）是

null

参数。结果是，当应用迁移时，

South

和您的字段将尝试设置这些参数

您会得到错误：

TypeError: __init__() got multiple values for keyword argument 'null'

我们如何解决这个问题

好的，我们可以告诉南方，我们将这些参数作为默认值传递，这样它就可以安全地忽略它们

因此，我们创建了一组如下规则：

add_introspection_rules([], ["^audit_log\.models\.fields\.LastUserField"])

(
  'action_user',
  self.gf('audit_log.models.fields.LastUserField')(
    related_name='_somemodel_audit_log_entry',
    null=True,
    to=orm['auth.User'],
  )
),

rules = [(                                          
    (fields.LastUserField,),                        
    [],                                             
    {                                               
        'to': ['rel.to', {'default': User}],        
        'null': ['null', {'default': True}],        
    },                                              
)]   
add_introspection_rules(                           
    rules,                                         
    ['^audit_log\.models\.fields\.LastUserField'], 
)       

因此，South现在了解了如何存储参数以及哪些参数需要忽略。因此，新字段定义如下：

(
  'action_user',
  self.gf('audit_log.models.fields.LastUserField')(
    related_name='_somemodel_audit_log_entry'
  )
),

---

正如我们所看到的，

相关的\u名称

仍然在这里，但是

to

和

null

参数已经消失。因此，现在我们可以安全地应用迁移而不会产生冲突。

尽管使用了@WoLpH答案中的步骤，但我仍然无法创建迁移。我不得不修改audit_log/models/fields.py文件。以下是我的LastUserField字段的外观：

class LastUserField(models.ForeignKey):
    """ 
    A field that keeps the last user that saved an instance
    of a model. None will be the value for AnonymousUser.
    """

    def __init__(self, **kwargs):
        kwargs.pop('null', None)
        kwargs.pop('to', None)
        super(LastUserField, self).__init__(User, null = True, **kwargs)

    def contribute_to_class(self, cls, name):
        super(LastUserField, self).contribute_to_class(cls, name)
        registry = registration.FieldRegistry(self.__class__)
        registry.add_field(cls, self)

在我不得不这样做之前，以下内容已添加到我的models.py文件（该文件不起作用）：

rules = [((fields.LastUserField,),
    [],    
    {   
        'to': ['rel.to', {'default': User}],
        'null': ['null', {'default': True}],
    },)]

# Add the rules for the `LastUserField`
add_introspection_rules(rules, ['^audit_log\.models\.fields\.LastUserField'])

---

有什么建议可以避免这种黑客行为吗？

问题是南方不知道如何迁移你的田地。对于自定义字段，您需要添加自己的自省规则，在这些规则中，您可以告诉south哪些参数是重要的，哪些可以忽略。如果今晚有时间的话，我会写一个如何让内省正常工作的例子。@WoLpH：是的，让内省工作起来是个问题，但谢天谢地，有内省的文档。我是模式迁移/django-south（以及django审计日志）的新手，对此我并不清楚。我尝试的前几件事与LastUserField不兼容。如果您能让内省工作起来，我将不胜感激（因此我不需要手动注入SQL），但说实话，我停止了自己的尝试，转而关注其他问题。我一直很忙，所以还没有时间给您一个正确的答案。请再容忍我一会儿：）（或者其他人可以解释一下）。长话短说，它不起作用，因为你没有告诉南方有关参数，所以它忽略了它，这导致它被传递了两次。我是django审计日志的作者。项目的GitHub页面位于此处：。如果人们在那里报告这样的问题和补丁，这将使软件包受益。我还没有将该应用程序与south结合使用，但我会关注这个问题。我已经创建并发布了关于这一点，并会考虑解决这个问题的最佳方法。