For example, if you had the following class:
```
class Person(Document):
name = StringField()
age = IntField()
```
You could instantiate an object of such class by doing one of the following:
1. `new_person = Person('Tom', 30)`
2. `new_person = Person('Tom', age=30)`
3. `new_person = Person(name='Tom', age=30)`
From now on, only option (3) is allowed.
Supporting positional arguments may sound like a reasonable idea in this
heavily simplified example, but in real life it's almost never what you want
(especially if you use inheritance in your document definitions) and it may
lead to ugly bugs. We should not rely on the *order* of fields to match a given
value to a given name.
This also helps us simplify the code e.g. by dropping the confusing (and
undocumented) `BaseDocument._auto_id_field` attribute.
For example, if you had the following class:
```
class Person(Document):
name = StringField()
age = IntField()
```
You could instantiate an object of such class by doing one of the following:
1. `new_person = Person('Tom', 30)`
2. `new_person = Person('Tom', age=30)`
3. `new_person = Person(name='Tom', age=30)`
From now on, only option (3) is allowed.
Supporting positional arguments may sound like a reasonable idea in this
heavily simplified example, but in real life it's almost never what you want
(especially if you use inheritance in your document definitions) and it may
lead to ugly bugs. We should not rely on the *order* of fields to match a given
value to a given name.
This also helps us simplify the code e.g. by dropping the confusing (and
undocumented) `BaseDocument._auto_id_field` attribute.
- expose disconnect
- disconnect cleans _connection_settings
- disconnect cleans cached collection in Document._collection
- re-connecting with the same alias raise an error (must call disconnect in between)
Without this commit save operation on first document would fail instead of immediate failure upon connection attempt. Such later failure is much less obvious.
