[Feature] Dynamic additional information rendering in frontend (#282)

This implements a version of #274, relying on Pydantics built in JSON schema and JSON rendering.
Requires additional UI tagging in the ai model repo but will remove HTML tags.

Example scenario with filled information: 5882df9c-dae1-4d80-a40e-db4724271456/scenario/3a4d395a-6a6d-4154-8ce3-ced667fceec0

Reviewed-on: enviPath/enviPy#282
Co-authored-by: Tobias O <tobias.olenyi@envipath.com>
Co-committed-by: Tobias O <tobias.olenyi@envipath.com>

epapi/utils/schema_transformers.py

@@ -0,0 +1,175 @@
+"""
+Schema transformation utilities for converting Pydantic models to RJSF format.
+
+This module provides functions to extract UI configuration from Pydantic models
+and transform them into React JSON Schema Form (RJSF) compatible format.
+"""
+
+from typing import Type, Optional, Any
+
+import jsonref
+from pydantic import BaseModel
+
+from envipy_additional_information.ui_config import UIConfig
+from envipy_additional_information import registry
+
+
+def extract_groups(model_cls: Type[BaseModel]) -> list[str]:
+    """
+    Extract groups from registry-stored group information.
+
+    Args:
+        model_cls: The model class
+
+    Returns:
+        List of group names the model belongs to
+    """
+    return registry.get_groups(model_cls)
+
+
+def extract_ui_metadata(model_cls: Type[BaseModel]) -> dict[str, Any]:
+    """
+    Extract model-level UI metadata from UI class.
+
+    Returns metadata attributes that are NOT UIConfig instances.
+    Common metadata includes: unit, description, title.
+    """
+    metadata: dict[str, Any] = {}
+
+    if not hasattr(model_cls, "UI"):
+        return metadata
+
+    ui_class = getattr(model_cls, "UI")
+
+    # Iterate over all attributes in the UI class
+    for attr_name in dir(ui_class):
+        # Skip private attributes
+        if attr_name.startswith("_"):
+            continue
+
+        # Get the attribute value
+        try:
+            attr_value = getattr(ui_class, attr_name)
+        except AttributeError:
+            continue
+
+        # Skip callables but keep types/classes
+        if callable(attr_value) and not isinstance(attr_value, type):
+            continue
+
+        # Skip UIConfig instances (these are field-level configs, not metadata)
+        # This includes both UIConfig and IntervalConfig
+        if isinstance(attr_value, UIConfig):
+            continue
+
+        metadata[attr_name] = attr_value
+
+    return metadata
+
+
+def extract_ui_config_from_model(model_cls: Type[BaseModel]) -> dict[str, Any]:
+    """
+    Extract UI configuration from model's UI class.
+
+    Returns a dictionary mapping field names to their UI schema configurations.
+    Trusts the config classes to handle their own transformation logic.
+    """
+    ui_configs: dict[str, Any] = {}
+
+    if not hasattr(model_cls, "UI"):
+        return ui_configs
+
+    ui_class = getattr(model_cls, "UI")
+    schema = model_cls.model_json_schema()
+    field_names = schema.get("properties", {}).keys()
+
+    # Extract config for each field
+    for field_name in field_names:
+        ui_config = getattr(ui_class, field_name)
+
+        if isinstance(ui_config, UIConfig):
+            ui_configs[field_name] = ui_config.to_ui_schema_field()
+
+    return ui_configs
+
+
+def build_ui_schema(model_cls: Type[BaseModel]) -> dict:
+    """Generate RJSF uiSchema from model's UI class."""
+    ui_schema = {}
+
+    # Extract field-level UI configs
+    field_configs = extract_ui_config_from_model(model_cls)
+
+    for field_name, config in field_configs.items():
+        ui_schema[field_name] = config
+
+    return ui_schema
+
+
+def build_schema(model_cls: Type[BaseModel]) -> dict[str, Any]:
+    """
+    Build JSON schema from Pydantic model, applying UI metadata.
+
+    Dereferences all $ref pointers to produce fully inlined schema.
+    This ensures the frontend receives schemas with enum values and nested
+    properties fully resolved, without needing client-side ref resolution.
+
+    Extracts model-level metadata from UI class (title, unit, etc.) and applies
+    it to the generated schema. This ensures UI metadata is the single source of truth.
+    """
+    schema = model_cls.model_json_schema()
+
+    # Dereference $ref pointers (inlines $defs) using jsonref
+    # This ensures the frontend receives schemas with enum values and nested
+    # properties fully resolved, currently necessary for client-side rendering.
+    # FIXME: This is a hack to get the schema to work with alpine schema-form.js replace once we migrate to client-side framework.
+    schema = jsonref.replace_refs(schema, proxies=False)
+
+    # Remove $defs section as all refs are now inlined
+    if "$defs" in schema:
+        del schema["$defs"]
+
+    # Extract and apply UI metadata (title, unit, description, etc.)
+    ui_metadata = extract_ui_metadata(model_cls)
+
+    # Apply all metadata consistently as custom properties with x- prefix
+    # This ensures consistency and avoids conflicts with standard JSON Schema properties
+    for key, value in ui_metadata.items():
+        if value is not None:
+            schema[f"x-{key}"] = value
+
+    # Set standard title property from UI metadata for JSON Schema compliance
+    if "label" in ui_metadata:
+        schema["title"] = ui_metadata["label"]
+
+    return schema
+
+
+def build_rjsf_output(model_cls: Type[BaseModel], initial_data: Optional[dict] = None) -> dict:
+    """
+    Main function that returns complete RJSF format.
+
+    Trusts the config classes to handle their own transformation logic.
+    No special-case handling - if a config knows how to transform itself, it will.
+
+    Returns:
+        dict with keys: schema, uiSchema, formData, groups
+    """
+    # Build schema with UI metadata applied
+    schema = build_schema(model_cls)
+
+    # Build UI schema - config classes handle their own transformation
+    ui_schema = build_ui_schema(model_cls)
+
+    # Extract groups from marker interfaces
+    groups = extract_groups(model_cls)
+
+    # Use provided initial_data or empty dict
+    form_data = initial_data if initial_data is not None else {}
+
+    return {
+        "schema": schema,
+        "uiSchema": ui_schema,
+        "formData": form_data,
+        "groups": groups,
+    }