Line of Dict of Elements

Overwrite validation and model dump.

Author: ax3l

schema/BaseElement.py

@@ -12,5 +12,5 @@ class BaseElement(BaseModel):
     # not only when an instance of BaseElement is created
     model_config = ConfigDict(validate_assignment=True)
 
-    # Unique element name
-    name: Optional[str] = None
+    # element name
+    name: str

schema/Line.py

@@ -1,5 +1,5 @@
-from pydantic import BaseModel, ConfigDict, Field
-from typing import Annotated, List, Literal, Union
+from pydantic import BaseModel, ConfigDict, Field, field_validator
+from typing import Annotated, Dict, List, Literal, Union
 
 from schema.BaseElement import BaseElement
 from schema.ThickElement import ThickElement
@@ -30,5 +30,53 @@ class Line(BaseModel):
     ]
 
 
+    @field_validator("line", mode="before")
+    @classmethod
+    def parse_list_of_dicts(cls, value):
+        """This method inserts the key of the one-key dictionary into
+           the name attribute of the elements"""
+        if not isinstance(value, list):
+            raise TypeError("line must be a list")
+
+        if value and isinstance(value[0], BaseModel):
+            # Already a list of models; nothing to do
+            return value
+
+        # Otherwise, treat as list of dicts
+        elements = []
+        for item_dict in value:
+            if not (isinstance(item_dict, dict) and len(item_dict) == 1):
+                raise ValueError(f"Each line element must be a dict with exactly one key, the name of the element, but we got: {item_dict!r}")
+            [(name, fields)] = item_dict.items()
+
+            # an element is either a reference string to another element or a dict
+            if not isinstance(fields, dict) and not isinstance(fields, str):
+                raise ValueError(f"Value for element key '{name}' must be a dict or str (got {fields!r})")
+
+            # Insert the name into the fields dict
+            fields["name"] = name
+            elements.append(fields)
+        return elements
+
+
+    def model_dump(self, *args, **kwargs):
+        """This makes sure the element name property is moved out and up to a one-key dictionary"""
+        # Use default dump for non-line fields
+        data = super().model_dump(*args, **kwargs)
+
+        # Reformat 'line' field as list of single-key dicts
+        new_line = []
+        for elem in self.line:
+            # The element's name is the dict key; dump all other fields except 'name'
+            elem_dict = elem.model_dump(exclude={"name"}, **kwargs)
+            name = getattr(elem, "name", None)
+            if name is None:
+                raise ValueError("Element missing 'name' attribute")
+            new_line.append({name: elem_dict})
+
+        data["line"] = new_line
+        return data
+
+
 # Avoid circular import issues
 Line.model_rebuild()