ModelRfield

Resource field for storing Pydantic BaseModelDTO objects.

ModelRfield provides automatic serialization and deserialization of Pydantic models (BaseModelDTO) to and from JSON. This ensures type-safe, validated storage of structured data objects with all the benefits of Pydantic.

The field automatically: - Serializes model instances to JSON strings using Pydantic - Deserializes JSON strings back to model instances - Validates data according to Pydantic model schema - Provides type hints and IDE support - Handles nested models and complex types

This is useful for: - Storing structured configuration objects - Complex data models with validation - API response objects - Typed data structures - Objects with nested relationships

Storage behavior: - Stored in KV_STORE by default - Not included in dict views by default (can be changed) - Automatically serialized to JSON on save - Automatically deserialized and validated on load

Example: ```python from gws_core.core.model.model_dto import BaseModelDTO from pydantic import Field

class UserConfig(BaseModelDTO):
    name: str
    age: int = Field(ge=0)
    email: str

class MyResource(Resource):
    # Store a user configuration object
    user_config = ModelRfield(object_type=UserConfig)

    # Included in dict view
    summary = ModelRfield(object_type=SummaryDTO, include_in_dict_view=True)

# Usage
resource = MyResource()
resource.user_config = UserConfig(name='John', age=30, email='john@example.com')
# Validation happens automatically via Pydantic
```

Note: - The object_type must be a subclass of BaseModelDTO - Pydantic validation is applied during deserialization - Models can have complex nested structures - Default value is None (model is not instantiated by default)

Attributes

include_in_dict_view: boolobject_type: typestorage: RFieldStorage

Functions

__init__

Initialize a ModelRfield for storing Pydantic model objects.

object_type : type

The Pydantic model class (subclass of BaseModelDTO) that this field will store. Must be a valid Pydantic model with proper validation schema.

include_in_dict_view : bool - False

If True, this field is included in dict/JSON representations. Set to False for large or complex models. Defaults to False

deserialize

Deserialize a JSON string into a Pydantic model instance.

This method is called when loading the field from storage. It uses Pydantic's from_json_str method to deserialize and validate the data.

r_field_value : Any

JSON string representation of the model, or None

Return type : BaseModelDTO

get_default_value

Get the default value for this field.

If the default value is a Type or Callable, it will be called to generate a new default value. Otherwise, the default value is returned directly.

This ensures that mutable defaults (like lists or dicts) are not shared between Resource instances.

Return type : Any

serialize

Serialize a Pydantic model instance to a JSON string.

This method is called when saving the field to storage. It uses Pydantic's to_json_str method to serialize the model.

r_field_value : BaseModelDTO

The Pydantic model instance to serialize, or None

Return type : Any

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