feat: Add JSON Cleaner Component (#2584)

Co-authored-by: autofix-ci[bot] <114827586+autofix-ci[bot]@users.noreply.github.com>
Co-authored-by: Gabriel Luiz Freitas Almeida <gabriel@langflow.org>

src/backend/base/langflow/components/prototypes/JSONCleaner.py

@@ -0,0 +1,93 @@
+import json
+import re
+import unicodedata
+from langflow.custom import Component
+from langflow.inputs import MessageTextInput, BoolInput
+from langflow.template import Output
+from langflow.schema.message import Message
+
+
+class JSONCleaner(Component):
+    display_name = "JSON Cleaner"
+    description = "Cleans the messy and sometimes incorrect JSON strings produced by LLMs so that they are fully compliant with the JSON spec."
+    icon = "custom_components"
+
+    inputs = [
+        MessageTextInput(
+            name="json_str", display_name="JSON String", info="The JSON string to be cleaned.", required=True
+        ),
+        BoolInput(
+            name="remove_control_chars",
+            display_name="Remove Control Characters",
+            info="Remove control characters from the JSON string.",
+            required=False,
+        ),
+        BoolInput(
+            name="normalize_unicode",
+            display_name="Normalize Unicode",
+            info="Normalize Unicode characters in the JSON string.",
+            required=False,
+        ),
+        BoolInput(
+            name="validate_json",
+            display_name="Validate JSON",
+            info="Validate the JSON string to ensure it is well-formed.",
+            required=False,
+        ),
+    ]
+
+    outputs = [
+        Output(display_name="Cleaned JSON String", name="output", method="clean_json"),
+    ]
+
+    def clean_json(self) -> Message:
+        try:
+            from json_repair import repair_json  # type: ignore
+        except ImportError:
+            raise ImportError(
+                "Could not import the json_repair package." "Please install it with `pip install json_repair`."
+            )
+
+        """Clean the input JSON string based on provided options and return the cleaned JSON string."""
+        json_str = self.json_str
+        remove_control_chars = self.remove_control_chars
+        normalize_unicode = self.normalize_unicode
+        validate_json = self.validate_json
+
+        try:
+            start = json_str.find("{")
+            end = json_str.rfind("}")
+            if start == -1 or end == -1:
+                raise ValueError("Invalid JSON string: Missing '{' or '}'")
+            json_str = json_str[start : end + 1]
+
+            if remove_control_chars:
+                json_str = self._remove_control_characters(json_str)
+            if normalize_unicode:
+                json_str = self._normalize_unicode(json_str)
+            if validate_json:
+                json_str = self._validate_json(json_str)
+
+            cleaned_json_str = repair_json(json_str)
+            result = str(cleaned_json_str)
+
+            self.status = result
+            return Message(text=result)
+        except Exception as e:
+            raise ValueError(f"Error cleaning JSON string: {str(e)}")
+
+    def _remove_control_characters(self, s: str) -> str:
+        """Remove control characters from the string."""
+        return re.sub(r"[\x00-\x1F\x7F]", "", s)
+
+    def _normalize_unicode(self, s: str) -> str:
+        """Normalize Unicode characters in the string."""
+        return unicodedata.normalize("NFC", s)
+
+    def _validate_json(self, s: str) -> str:
+        """Validate the JSON string."""
+        try:
+            json.loads(s)
+            return s
+        except json.JSONDecodeError as e:
+            raise ValueError(f"Invalid JSON string: {str(e)}")