Refactor field serialization and add model

serialization in Template and FrontendNode classes

src/backend/langflow/template/field/base.py

@@ -1,11 +1,11 @@
 from abc import ABC
 from typing import Any, Optional, Union
 
-from pydantic import BaseModel
+from pydantic import BaseModel, Field, field_serializer, model_serializer
 
 
 class TemplateFieldCreator(BaseModel, ABC):
-    field_type: str = "str"
+    field_type: str = Field(default="str", alias="type")
     """The type of field this is. Default is a string."""
 
     required: bool = False
@@ -14,7 +14,7 @@ class TemplateFieldCreator(BaseModel, ABC):
     placeholder: str = ""
     """A placeholder string for the field. Default is an empty string."""
 
-    is_list: bool = False
+    is_list: bool = Field(default=False, alias="list")
     """Defines if the field is a list. Default is False."""
 
     show: bool = True
@@ -26,7 +26,7 @@ class TemplateFieldCreator(BaseModel, ABC):
     value: Any = None
     """The value of the field. Default is None."""
 
-    file_types: list[str] = []
+    file_types: list[str] = Field(default=[], alias="fileTypes")
     """List of file types associated with the field. Default is an empty list. (duplicate)"""
 
     file_path: Union[str, None] = None
@@ -35,7 +35,7 @@ class TemplateFieldCreator(BaseModel, ABC):
     password: bool = False
     """Specifies if the field is a password. Defaults to False."""
 
-    options: list[str] = []
+    options: list[str] = None
     """List of options for the field. Only used when is_list=True. Default is an empty list."""
 
     name: str = ""
@@ -47,7 +47,7 @@ class TemplateFieldCreator(BaseModel, ABC):
     advanced: bool = False
     """Specifies if the field will an advanced parameter (hidden). Defaults to False."""
 
-    input_types: list[str] = []
+    input_types: Optional[list[str]] = None
     """List of input types for the handle when the field has more than one type. Default is an empty list."""
 
     dynamic: bool = False
@@ -59,22 +59,31 @@ class TemplateFieldCreator(BaseModel, ABC):
     refresh: Optional[bool] = None
     """Specifies if the field should be refreshed. Defaults to False."""
 
-    def to_dict(self):
-        result = self.model_dump()
-        # Remove key if it is None
-        for key in list(result.keys()):
-            if result[key] is None or result[key] == [] and key != "value":
-                del result[key]
-        result["type"] = result.pop("field_type")
-        result["list"] = result.pop("is_list")
-
-        if result.get("file_types"):
-            result["fileTypes"] = result.pop("file_types")
-
-        if self.field_type == "file":
-            result["file_path"] = self.file_path
+    @model_serializer(mode="wrap")
+    def serialize_model(self, handler):
+        # This will be the result of model_dump or dict()
+        # so we need to build a dict to return
+        result = handler(self)
+        result["value"] = self.value
         return result
 
 
+
+        # for key in list(result.keys()):
+        #     if result[key] is None or result[key] == [] and key != "value":
+        #         del result[key]
+        # return result
+
+    def to_dict(self):
+        return self.model_dump(by_alias=True, exclude_none=True)
+
+
+    @field_serializer("file_path")
+    def serialize_file_path(self, value):
+        if self.field_type == "file":
+            return value
+        return None
+
+
 class TemplateField(TemplateFieldCreator):
     pass

src/backend/langflow/template/frontend_node/base.py

@@ -3,11 +3,12 @@ from collections import defaultdict
 from typing import ClassVar, Dict, List, Optional
 
 from langflow.template.field.base import TemplateField
-from langflow.template.frontend_node.constants import CLASSES_TO_REMOVE, FORCE_SHOW_FIELDS
+from langflow.template.frontend_node.constants import (CLASSES_TO_REMOVE,
+                                                       FORCE_SHOW_FIELDS)
 from langflow.template.frontend_node.formatter import field_formatters
 from langflow.template.template.base import Template
 from langflow.utils import constants
-from pydantic import BaseModel, Field
+from pydantic import BaseModel, Field, field_serializer, model_serializer
 
 
 class FieldFormatters(BaseModel):
@@ -63,26 +64,31 @@ class FrontendNode(BaseModel):
         """Sets the documentation of the frontend node."""
         self.documentation = documentation
 
-    def process_base_classes(self) -> None:
+    @field_serializer("base_classes")
+    def process_base_classes(self, base_classes: List[str]) -> List[str]:
         """Removes unwanted base classes from the list of base classes."""
-        self.base_classes = [base_class for base_class in self.base_classes if base_class not in CLASSES_TO_REMOVE]
+
+        return [base_class for base_class in base_classes if base_class not in CLASSES_TO_REMOVE]
+
+    @field_serializer("display_name")
+    def process_display_name(self, display_name: str) -> str:
+        """Sets the display name of the frontend node."""
+
+        return display_name or self.name
+
+
+    @model_serializer(mode="wrap")
+    def serialize(self, handler):
+        result = handler(self)
+        result["template"] = self.template.to_dict(self.format_field)
+        name = result.pop("name")
+
+        return {name: result}
 
     def to_dict(self) -> dict:
         """Returns a dict representation of the frontend node."""
-        self.process_base_classes()
-        return {
-            self.name: {
-                "template": self.template.to_dict(self.format_field),
-                "description": self.description,
-                "base_classes": self.base_classes,
-                "display_name": self.display_name or self.name,
-                "custom_fields": self.custom_fields,
-                "output_types": self.output_types,
-                "documentation": self.documentation,
-                "beta": self.beta,
-                "error": self.error,
-            },
-        }
+
+        return self.model_dump(by_alias=True, exclude_none=True)
 
     def add_extra_fields(self) -> None:
         pass

src/backend/langflow/template/template/base.py

@@ -1,9 +1,8 @@
-from typing import Callable, Optional, Union
-
-from pydantic import BaseModel
+from typing import Callable, Union
 
 from langflow.template.field.base import TemplateField
 from langflow.utils.constants import DIRECT_TYPES
+from pydantic import BaseModel, model_serializer
 
 
 class Template(BaseModel):
@@ -12,12 +11,11 @@ class Template(BaseModel):
 
     def process_fields(
         self,
-        name: Optional[str] = None,
         format_field_func: Union[Callable, None] = None,
     ):
         if format_field_func:
             for field in self.fields:
-                format_field_func(field, name)
+                format_field_func(field, self.type_name)
 
     def sort_fields(self):
         # first sort alphabetically
@@ -25,12 +23,20 @@ class Template(BaseModel):
         self.fields.sort(key=lambda x: x.name)
         self.fields.sort(key=lambda x: x.field_type in DIRECT_TYPES, reverse=False)
 
-    def to_dict(self, format_field_func=None):
-        self.process_fields(self.type_name, format_field_func)
-        self.sort_fields()
-        result = {field.name: field.to_dict() for field in self.fields}
-        result["_type"] = self.type_name  # type: ignore
+    @model_serializer(mode="wrap")
+    def serialize_model(self, handler):
+        result = handler(self)
+        for field in self.fields:
+            result[field.name] = field.to_dict()
+        result["_type"] = result.pop("type_name")
         return result
 
+    def to_dict(self, format_field_func=None):
+        self.process_fields(format_field_func)
+        self.sort_fields()
+        # result = {field.name: field.to_dict() for field in self.fields}
+        # result["_type"] = self.type_name  # type: ignore
+        return self.model_dump(by_alias=True, exclude_none=True, exclude={"fields"})
+
     def add_field(self, field: TemplateField) -> None:
         self.fields.append(field)