From d90219b03ef7956df2a7716988a5193f18bc67ab Mon Sep 17 00:00:00 2001
From: Axel Huebl <axel.huebl@plasma.ninja>
Date: Wed, 9 Jul 2025 14:04:45 -0700
Subject: [PATCH 1/2] Line of Dict of Elements

Overwrite validation and model dump.
---
 schema/BaseElement.py |  6 ++---
 schema/Line.py        | 56 ++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 58 insertions(+), 4 deletions(-)

diff --git a/schema/BaseElement.py b/schema/BaseElement.py
index 825635e..43b63b6 100644
--- a/schema/BaseElement.py
+++ b/schema/BaseElement.py
@@ -1,5 +1,5 @@
 from pydantic import BaseModel, ConfigDict
-from typing import Literal, Optional
+from typing import Literal
 
 
 class BaseElement(BaseModel):
@@ -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
diff --git a/schema/Line.py b/schema/Line.py
index e1ad070..48c1580 100644
--- a/schema/Line.py
+++ b/schema/Line.py
@@ -1,4 +1,4 @@
-from pydantic import BaseModel, ConfigDict, Field
+from pydantic import BaseModel, ConfigDict, Field, field_validator
 from typing import Annotated, List, Literal, Union
 
 from schema.BaseElement import BaseElement
@@ -29,6 +29,60 @@ 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
+
+        # we expect a list of dicts or strings
+        elements = []
+        for item_dict in value:
+            # an element is either a reference string to another element or a dict
+            if isinstance(item_dict, str):
+                raise RuntimeError("Reference/alias elements not yet implemented")
+
+            elif isinstance(item_dict, dict):
+                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()
+
+                if not isinstance(fields, dict):
+                    raise ValueError(
+                        f"Value for element key '{name}' must be a dict (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()

From fd931a1320385344ca4c307d122a61f93519db3c Mon Sep 17 00:00:00 2001
From: Axel Huebl <axel.huebl@plasma.ninja>
Date: Wed, 16 Jul 2025 08:16:44 -0700
Subject: [PATCH 2/2] Fix BaseElement (de)serialization

Co-authored-by: Edoardo Zoni <ezoni@lbl.gov>
---
 schema/BaseElement.py | 9 +++++++++
 schema/Line.py        | 9 +++------
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/schema/BaseElement.py b/schema/BaseElement.py
index 43b63b6..9b361b2 100644
--- a/schema/BaseElement.py
+++ b/schema/BaseElement.py
@@ -14,3 +14,12 @@ class BaseElement(BaseModel):
 
     # element name
     name: str
+
+    def model_dump(self, *args, **kwargs):
+        """This makes sure the element name property is moved out and up to a one-key dictionary"""
+        elem_dict = super().model_dump(*args, **kwargs)
+        name = elem_dict.pop("name", None)
+        if name is None:
+            raise ValueError("Element missing 'name' attribute")
+        data = [{name: elem_dict}]
+        return data
diff --git a/schema/Line.py b/schema/Line.py
index 48c1580..b1e0b13 100644
--- a/schema/Line.py
+++ b/schema/Line.py
@@ -73,12 +73,9 @@ def model_dump(self, *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})
+            #  Use custom dump for each line element
+            elem_dict = elem.model_dump(**kwargs)[0]
+            new_line.append(elem_dict)
 
         data["line"] = new_line
         return data