302 lines
7.5 KiB
Markdown
302 lines
7.5 KiB
Markdown
<a name="fields.base"></a>
|
|
# fields.base
|
|
|
|
<a name="fields.base.BaseField"></a>
|
|
## BaseField Objects
|
|
|
|
```python
|
|
class BaseField(FieldInfo)
|
|
```
|
|
|
|
BaseField serves as a parent class for all basic Fields in ormar.
|
|
It keeps all common parameters available for all fields as well as
|
|
set of useful functions.
|
|
|
|
All values are kept as class variables, ormar Fields are never instantiated.
|
|
Subclasses pydantic.FieldInfo to keep the fields related
|
|
to pydantic field types like ConstrainedStr
|
|
|
|
<a name="fields.base.BaseField.is_valid_uni_relation"></a>
|
|
#### is\_valid\_uni\_relation
|
|
|
|
```python
|
|
| @classmethod
|
|
| is_valid_uni_relation(cls) -> bool
|
|
```
|
|
|
|
Checks if field is a relation definition but only for ForeignKey relation,
|
|
so excludes ManyToMany fields, as well as virtual ForeignKey
|
|
(second side of FK relation).
|
|
|
|
Is used to define if a field is a db ForeignKey column that
|
|
should be saved/populated when dealing with internal/own
|
|
Model columns only.
|
|
|
|
**Returns**:
|
|
|
|
`(bool)`: result of the check
|
|
|
|
<a name="fields.base.BaseField.get_alias"></a>
|
|
#### get\_alias
|
|
|
|
```python
|
|
| @classmethod
|
|
| get_alias(cls) -> str
|
|
```
|
|
|
|
Used to translate Model column names to database column names during db queries.
|
|
|
|
**Returns**:
|
|
|
|
`(str)`: returns custom database column name if defined by user,
|
|
otherwise field name in ormar/pydantic
|
|
|
|
<a name="fields.base.BaseField.is_valid_field_info_field"></a>
|
|
#### is\_valid\_field\_info\_field
|
|
|
|
```python
|
|
| @classmethod
|
|
| is_valid_field_info_field(cls, field_name: str) -> bool
|
|
```
|
|
|
|
Checks if field belongs to pydantic FieldInfo
|
|
- used during setting default pydantic values.
|
|
Excludes defaults and alias as they are populated separately
|
|
(defaults) or not at all (alias)
|
|
|
|
**Arguments**:
|
|
|
|
- `field_name (str)`: field name of BaseFIeld
|
|
|
|
**Returns**:
|
|
|
|
`(bool)`: True if field is present on pydantic.FieldInfo
|
|
|
|
<a name="fields.base.BaseField.convert_to_pydantic_field_info"></a>
|
|
#### convert\_to\_pydantic\_field\_info
|
|
|
|
```python
|
|
| @classmethod
|
|
| convert_to_pydantic_field_info(cls, allow_null: bool = False) -> FieldInfo
|
|
```
|
|
|
|
Converts a BaseField into pydantic.FieldInfo
|
|
that is later easily processed by pydantic.
|
|
Used in an ormar Model Metaclass.
|
|
|
|
**Arguments**:
|
|
|
|
- `allow_null (bool)`: flag if the default value can be None
|
|
or if it should be populated by pydantic Undefined
|
|
|
|
**Returns**:
|
|
|
|
`(pydantic.FieldInfo)`: actual instance of pydantic.FieldInfo with all needed fields populated
|
|
|
|
<a name="fields.base.BaseField.default_value"></a>
|
|
#### default\_value
|
|
|
|
```python
|
|
| @classmethod
|
|
| default_value(cls, use_server: bool = False) -> Optional[FieldInfo]
|
|
```
|
|
|
|
Returns a FieldInfo instance with populated default
|
|
(static) or default_factory (function).
|
|
If the field is a autoincrement primary key the default is None.
|
|
Otherwise field have to has either default, or default_factory populated.
|
|
|
|
If all default conditions fail None is returned.
|
|
|
|
Used in converting to pydantic FieldInfo.
|
|
|
|
**Arguments**:
|
|
|
|
- `use_server (bool)`: flag marking if server_default should be
|
|
treated as default value, default False
|
|
|
|
**Returns**:
|
|
|
|
`(Optional[pydantic.FieldInfo])`: returns a call to pydantic.Field
|
|
which is returning a FieldInfo instance
|
|
|
|
<a name="fields.base.BaseField.get_default"></a>
|
|
#### get\_default
|
|
|
|
```python
|
|
| @classmethod
|
|
| get_default(cls, use_server: bool = False) -> Any
|
|
```
|
|
|
|
Return default value for a field.
|
|
If the field is Callable the function is called and actual result is returned.
|
|
Used to populate default_values for pydantic Model in ormar Model Metaclass.
|
|
|
|
**Arguments**:
|
|
|
|
- `use_server (bool)`: flag marking if server_default should be
|
|
treated as default value, default False
|
|
|
|
**Returns**:
|
|
|
|
`(Any)`: default value for the field if set, otherwise implicit None
|
|
|
|
<a name="fields.base.BaseField.has_default"></a>
|
|
#### has\_default
|
|
|
|
```python
|
|
| @classmethod
|
|
| has_default(cls, use_server: bool = True) -> bool
|
|
```
|
|
|
|
Checks if the field has default value set.
|
|
|
|
**Arguments**:
|
|
|
|
- `use_server (bool)`: flag marking if server_default should be
|
|
treated as default value, default False
|
|
|
|
**Returns**:
|
|
|
|
`(bool)`: result of the check if default value is set
|
|
|
|
<a name="fields.base.BaseField.is_auto_primary_key"></a>
|
|
#### is\_auto\_primary\_key
|
|
|
|
```python
|
|
| @classmethod
|
|
| is_auto_primary_key(cls) -> bool
|
|
```
|
|
|
|
Checks if field is first a primary key and if it,
|
|
it's than check if it's set to autoincrement.
|
|
Autoincrement primary_key is nullable/optional.
|
|
|
|
**Returns**:
|
|
|
|
`(bool)`: result of the check for primary key and autoincrement
|
|
|
|
<a name="fields.base.BaseField.construct_constraints"></a>
|
|
#### construct\_constraints
|
|
|
|
```python
|
|
| @classmethod
|
|
| construct_constraints(cls) -> List
|
|
```
|
|
|
|
Converts list of ormar constraints into sqlalchemy ForeignKeys.
|
|
Has to be done dynamically as sqlalchemy binds ForeignKey to the table.
|
|
And we need a new ForeignKey for subclasses of current model
|
|
|
|
**Returns**:
|
|
|
|
`(List[sqlalchemy.schema.ForeignKey])`: List of sqlalchemy foreign keys - by default one.
|
|
|
|
<a name="fields.base.BaseField.get_column"></a>
|
|
#### get\_column
|
|
|
|
```python
|
|
| @classmethod
|
|
| get_column(cls, name: str) -> sqlalchemy.Column
|
|
```
|
|
|
|
Returns definition of sqlalchemy.Column used in creation of sqlalchemy.Table.
|
|
Populates name, column type constraints, as well as a number of parameters like
|
|
primary_key, index, unique, nullable, default and server_default.
|
|
|
|
**Arguments**:
|
|
|
|
- `name (str)`: name of the db column - used if alias is not set
|
|
|
|
**Returns**:
|
|
|
|
`(sqlalchemy.Column)`: actual definition of the database column as sqlalchemy requires.
|
|
|
|
<a name="fields.base.BaseField.expand_relationship"></a>
|
|
#### expand\_relationship
|
|
|
|
```python
|
|
| @classmethod
|
|
| expand_relationship(cls, value: Any, child: Union["Model", "NewBaseModel"], to_register: bool = True) -> Any
|
|
```
|
|
|
|
Function overwritten for relations, in basic field the value is returned as is.
|
|
For relations the child model is first constructed (if needed),
|
|
registered in relation and returned.
|
|
For relation fields the value can be a pk value (Any type of field),
|
|
dict (from Model) or actual instance/list of a "Model".
|
|
|
|
**Arguments**:
|
|
|
|
- `value (Any)`: a Model field value, returned untouched for non relation fields.
|
|
- `child (Union["Model", "NewBaseModel"])`: a child Model to register
|
|
- `to_register (bool)`: flag if the relation should be set in RelationshipManager
|
|
|
|
**Returns**:
|
|
|
|
`(Any)`: returns untouched value for normal fields, expands only for relations
|
|
|
|
<a name="fields.base.BaseField.set_self_reference_flag"></a>
|
|
#### set\_self\_reference\_flag
|
|
|
|
```python
|
|
| @classmethod
|
|
| set_self_reference_flag(cls) -> None
|
|
```
|
|
|
|
Sets `self_reference` to True if field to and owner are same model.
|
|
|
|
**Returns**:
|
|
|
|
`(None)`: None
|
|
|
|
<a name="fields.base.BaseField.has_unresolved_forward_refs"></a>
|
|
#### has\_unresolved\_forward\_refs
|
|
|
|
```python
|
|
| @classmethod
|
|
| has_unresolved_forward_refs(cls) -> bool
|
|
```
|
|
|
|
Verifies if the filed has any ForwardRefs that require updating before the
|
|
model can be used.
|
|
|
|
**Returns**:
|
|
|
|
`(bool)`: result of the check
|
|
|
|
<a name="fields.base.BaseField.evaluate_forward_ref"></a>
|
|
#### evaluate\_forward\_ref
|
|
|
|
```python
|
|
| @classmethod
|
|
| evaluate_forward_ref(cls, globalns: Any, localns: Any) -> None
|
|
```
|
|
|
|
Evaluates the ForwardRef to actual Field based on global and local namespaces
|
|
|
|
**Arguments**:
|
|
|
|
- `globalns (Any)`: global namespace
|
|
- `localns (Any)`: local namespace
|
|
|
|
**Returns**:
|
|
|
|
`(None)`: None
|
|
|
|
<a name="fields.base.BaseField.get_related_name"></a>
|
|
#### get\_related\_name
|
|
|
|
```python
|
|
| @classmethod
|
|
| get_related_name(cls) -> str
|
|
```
|
|
|
|
Returns name to use for reverse relation.
|
|
It's either set as `related_name` or by default it's owner model. get_name + 's'
|
|
|
|
**Returns**:
|
|
|
|
`(str)`: name of the related_name or default related name.
|
|
|