generics, polymorphism, and the plug-in requirement

[cobycloud]

Generic Concrete classes should be able to support polymorphism, including third party plug-ins.

This requires that typing be updated in the model JSON schema, annotations, and attribute definition.

Additionally this requires a mapping of type Literal to a reference of a Module in Memory.

[RafaelJohn9]

While using pydantic, you likely have come across Validation Errors that occur when you have nested polymorphic instances inside a class utilizing pydantic.

In Swarmauri we encountered a similar problem while trying to create polymorphic instances of tools inside toolkits

Example of this is:

class AccessibilityToolkit(ToolkitBase):
    type: Literal["AccessibilityToolkit"] = "AccessibilityToolkit"

    resource: str = "AccessibilityToolkit"

    # Explicitly define the tools as fields
    automated_readability_index_tool: AutomatedReadabilityIndexTool = Field(
        default_factory=lambda: AutomatedReadabilityIndexTool(
            name="AutomatedReadabilityIndexTool"
        )
    )
    coleman_liau_index_tool: ColemanLiauIndexTool = Field(
        default_factory=lambda: ColemanLiauIndexTool(name="ColemanLiauIndexTool")
    )
    flesch_kincaid_tool: FleschKincaidTool = Field(
        default_factory=lambda: FleschKincaidTool(name="FleschKincaidTool")
    )
    flesch_reading_ease_tool: FleschReadingEaseTool = Field(
        default_factory=lambda: FleschReadingEaseTool(name="FleschReadingEaseTool")
    )
    gunning_fog_tool: GunningFogTool = Field(
        default_factory=lambda: GunningFogTool(name="GunningFogTool")
    )

    def __init__(self, **kwargs):
        super().__init__(**kwargs)

        # Add all tools to the toolkit using add_tools method
        self.add_tool(self.automated_readability_index_tool)
        self.add_tool(self.coleman_liau_index_tool)
        self.add_tool(self.flesch_kincaid_tool)
        self.add_tool(self.flesch_reading_ease_tool)
        self.add_tool(self.gunning_fog_tool) 

The toolkit and the tools both inherit from Pydantic's BaseModel.

During deserialization, pydantic was not correctly to determine the type of tool that is:

Expected type [ToolBase]  got [AutomatedReadabilityIndexTool]

This type of errors show that the deserialization wasn't able to correctly figure out the SubClasses of ToolBase

Well, when this happens manual validation of the classes is required. The manual validation should satisfy flexibility in terms of adding new tools in the toolkit.

Here is the solution used to solve the problem

 @model_validator(mode="wrap")
    @classmethod
    def validate_model(cls, values: Any, handler: Any):
        # Extract the tools and validate their types manually
        tools = values.get("tools", {})

        for tool_name, tool_data in tools.items():
            if isinstance(tool_data, dict):
                tool_type = tool_data.get("type")
                tool_id = tool_data.get("id")  # Preserve the ID if it exists

                try:
                    # Assuming SubclassUnion returns a dictionary or a list of tool classes
                    tool_class = next(
                        sc
                        for sc in SubclassUnion.__swm__get_subclasses__(ToolBase)
                        if sc.__name__ == tool_type
                    )

                    logging.info(tool_class)

                    # Create an instance of the tool class
                    tools[tool_name] = tool_class(**tool_data)
                    tools[
                        tool_name
                    ].id = tool_id  # Ensure the tool ID is not changed unintentionally
                except StopIteration:
                    raise ValueError(f"Unknown tool type: {tool_type}")

        values["tools"] = tools
        return handler(values)

The solution above provides the flexibility required by utilizing SubclassUnion to get the subclasses of the tools and correctly get the polymorphic instances of them and returns them.

[RafaelJohn9]

This issue was fixed by PR https://github.com/swarmauri/swarmauri-sdk/pull/423