feat: new AlterMetadataComponent enhances Data and Message objects with dict or Data object entries (#4634)

* creating AddMetadataComponent

* [autofix.ci] apply automated fixes

* fixing lint

* allow removal of metadata fields

* [autofix.ci] apply automated fixes

* Fix the name of alter metadata

---------

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Eric Hare <ericrhare@gmail.com>

src/backend/base/langflow/components/processing/__init__.py

@@ -1,3 +1,4 @@
+from .alter_metadata import AlterMetadataComponent
 from .combine_text import CombineTextComponent
 from .create_data import CreateDataComponent
 from .extract_key import ExtractDataKeyComponent
@@ -12,6 +13,7 @@ from .split_text import SplitTextComponent
 from .update_data import UpdateDataComponent
 
 __all__ = [
+    "AlterMetadataComponent",
     "CombineTextComponent",
     "CreateDataComponent",
     "DataFilterComponent",

src/backend/base/langflow/components/processing/alter_metadata.py

@@ -0,0 +1,90 @@
+from langflow.custom import Component
+from langflow.inputs import MessageTextInput
+from langflow.io import HandleInput, NestedDictInput, Output, StrInput
+from langflow.schema import Data
+
+
+class AlterMetadataComponent(Component):
+    display_name = "Alter Metadata"
+    description = "Adds/Removes Metadata Dictionary on inputs"
+    icon = "merge"
+    name = "AlterMetadata"
+
+    inputs = [
+        HandleInput(
+            name="input_value",
+            display_name="Input",
+            info="Object(s) to which Metadata should be added",
+            required=False,
+            input_types=["Message", "Data"],
+            is_list=True,
+        ),
+        StrInput(
+            name="text_in",
+            display_name="User Text",
+            info="Text input; value will be in 'text' attribute of Data object. Empty text entries are ignored.",
+            required=False,
+        ),
+        NestedDictInput(
+            name="metadata",
+            display_name="Metadata",
+            info="Metadata to add to each object",
+            input_types=["Data"],
+            required=True,
+        ),
+        MessageTextInput(
+            name="remove_fields",
+            display_name="Fields to Remove",
+            info="Metadata Fields to Remove",
+            required=False,
+            is_list=True,
+        ),
+    ]
+
+    outputs = [
+        Output(
+            name="data",
+            display_name="Data",
+            info="List of Input objects each with added Metadata",
+            method="process_output",
+        ),
+    ]
+
+    def _as_clean_dict(self, obj):
+        """Convert a Data object or a standard dictionary to a standard dictionary."""
+        if isinstance(obj, dict):
+            as_dict = obj
+        elif isinstance(obj, Data):
+            as_dict = obj.data
+        else:
+            msg = f"Expected a Data object or a dictionary but got {type(obj)}."
+            raise TypeError(msg)
+
+        return {k: v for k, v in (as_dict or {}).items() if k and k.strip()}
+
+    def process_output(self) -> list[Data]:
+        # Ensure metadata is a dictionary, filtering out any empty keys
+        metadata = self._as_clean_dict(self.metadata)
+
+        # Convert text_in to a Data object if it exists, and initialize our list of Data objects
+        data_objects = [Data(text=self.text_in)] if self.text_in else []
+
+        # Append existing Data objects from input_value, if any
+        if self.input_value:
+            data_objects.extend(self.input_value)
+
+        # Update each Data object with the new metadata, preserving existing fields
+        for data in data_objects:
+            data.data.update(metadata)
+
+        # Handle removal of fields specified in remove_fields
+        if self.remove_fields:
+            fields_to_remove = {field.strip() for field in self.remove_fields if field.strip()}
+
+            # Remove specified fields from each Data object's metadata
+            for data in data_objects:
+                data.data = {k: v for k, v in data.data.items() if k not in fields_to_remove}
+
+        # Set the status for tracking/debugging purposes
+        self.status = data_objects
+        return data_objects