Feature: Fields are now converted to title case by default (#1436)

If no display_name is provided, the name of the Field is the title case
version of the name. (e.g file_path -> File Path)

The user has the option to deactivate this behaviour in a field by field
basis by passing `title_case=False`.

src/backend/langflow/interface/custom/utils.py

@@ -17,7 +17,9 @@ from langflow.interface.custom.directory_reader.utils import (
 )
 from langflow.interface.importing.utils import eval_custom_component_code
 from langflow.template.field.base import TemplateField
-from langflow.template.frontend_node.custom_components import CustomComponentFrontendNode
+from langflow.template.frontend_node.custom_components import (
+    CustomComponentFrontendNode,
+)
 from langflow.utils.util import get_base_classes
 from loguru import logger
 
@@ -121,7 +123,7 @@ def add_new_custom_field(
 ):
     # Check field_config if any of the keys are in it
     # if it is, update the value
-    display_name = field_config.pop("display_name", field_name)
+    display_name = field_config.pop("display_name", None)
     field_type = field_config.pop("field_type", field_type)
     field_contains_list = "list" in field_type.lower()
     field_type = process_type(field_type)
@@ -187,7 +189,11 @@ def get_field_dict(field: Union[TemplateField, dict]):
     return field
 
 
-def run_build_config(custom_component: CustomComponent, user_id: Optional[Union[str, UUID]] = None, update_field=None):
+def run_build_config(
+    custom_component: CustomComponent,
+    user_id: Optional[Union[str, UUID]] = None,
+    update_field=None,
+):
     """Build the field configuration for a custom component"""
 
     try:
@@ -376,7 +382,16 @@ def update_field_dict(field_dict):
 
 def sanitize_field_config(field_config: Dict):
     # If any of the already existing keys are in field_config, remove them
-    for key in ["name", "field_type", "value", "required", "placeholder", "display_name", "advanced", "show"]:
+    for key in [
+        "name",
+        "field_type",
+        "value",
+        "required",
+        "placeholder",
+        "display_name",
+        "advanced",
+        "show",
+    ]:
         field_config.pop(key, None)
     return field_config
 

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

@@ -1,8 +1,7 @@
 from typing import Any, Callable, Optional, Union
 
-from pydantic import BaseModel, ConfigDict, Field, field_serializer
-
 from langflow.field_typing.range_spec import RangeSpec
+from pydantic import BaseModel, ConfigDict, Field, field_serializer
 
 
 class TemplateField(BaseModel):
@@ -64,6 +63,9 @@ class TemplateField(BaseModel):
     range_spec: Optional[RangeSpec] = Field(default=None, serialization_alias="rangeSpec")
     """Range specification for the field. Defaults to None."""
 
+    title_case: bool = True
+    """Specifies if the field should be displayed in title case. Defaults to True."""
+
     def to_dict(self):
         return self.model_dump(by_alias=True, exclude_none=True)
 
@@ -76,3 +78,15 @@ class TemplateField(BaseModel):
         if value == "float" and self.range_spec is None:
             self.range_spec = RangeSpec()
         return value
+
+    @field_serializer("display_name")
+    def serialize_display_name(self, value, _info):
+        # If display_name is not set, use name and convert to title case
+        # if title_case is True
+        if value is None:
+            # name is probably a snake_case string
+            # Ex: "file_path" -> "File Path"
+            value = self.name.replace("_", " ")
+            if self.title_case:
+                value = value.title()
+        return value