feat: nltk text splitter support (#3403)

* feat: nltk text splitter support

* feat: add doc link to nltk text splitter

* [autofix.ci] apply automated fixes

---------

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

src/backend/base/langflow/components/textsplitters/NaturalLanguageTextSplitter.py

@@ -0,0 +1,62 @@
+from typing import Any
+
+from langchain_text_splitters import NLTKTextSplitter, TextSplitter
+
+from langflow.base.textsplitters.model import LCTextSplitterComponent
+from langflow.inputs import DataInput, IntInput, MessageTextInput
+from langflow.utils.util import unescape_string
+
+
+class NaturalLanguageTextSplitterComponent(LCTextSplitterComponent):
+    display_name = "Natural Language Text Splitter"
+    description = "Split text based on natural language boundaries, optimized for a specified language."
+    documentation = (
+        "https://python.langchain.com/v0.1/docs/modules/data_connection/document_transformers/split_by_token/#nltk"
+    )
+    name = "NaturalLanguageTextSplitter"
+
+    inputs = [
+        IntInput(
+            name="chunk_size",
+            display_name="Chunk Size",
+            info="The maximum number of characters in each chunk after splitting.",
+            value=1000,
+        ),
+        IntInput(
+            name="chunk_overlap",
+            display_name="Chunk Overlap",
+            info="The number of characters that overlap between consecutive chunks.",
+            value=200,
+        ),
+        DataInput(
+            name="data_input",
+            display_name="Input",
+            info="The text data to be split.",
+            input_types=["Document", "Data"],
+        ),
+        MessageTextInput(
+            name="separator",
+            display_name="Separator",
+            info='The character(s) to use as a delimiter when splitting text.\nDefaults to "\\n\\n" if left empty.',
+        ),
+        MessageTextInput(
+            name="language",
+            display_name="Language",
+            info='The language of the text. Default is "English". Supports multiple languages for better text boundary recognition.',
+        ),
+    ]
+
+    def get_data_input(self) -> Any:
+        return self.data_input
+
+    def build_text_splitter(self) -> TextSplitter:
+        if self.separator:
+            separator = unescape_string(self.separator)
+        else:
+            separator = "\n\n"
+        return NLTKTextSplitter(
+            language=self.language.lower() if self.language else "english",
+            separator=separator,
+            chunk_size=self.chunk_size,
+            chunk_overlap=self.chunk_overlap,
+        )

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

@@ -1,9 +1,11 @@
 from .CharacterTextSplitter import CharacterTextSplitterComponent
 from .LanguageRecursiveTextSplitter import LanguageRecursiveTextSplitterComponent
 from .RecursiveCharacterTextSplitter import RecursiveCharacterTextSplitterComponent
+from .NaturalLanguageTextSplitter import NaturalLanguageTextSplitterComponent
 
 __all__ = [
     "CharacterTextSplitterComponent",
     "LanguageRecursiveTextSplitterComponent",
     "RecursiveCharacterTextSplitterComponent",
+    "NaturalLanguageTextSplitterComponent",
 ]