feat: update generate answer

Author: VinciGit00

scrapegraphai/nodes/generate_answer_node.py

@@ -2,6 +2,7 @@
 GenerateAnswerNode Module
 """
 from typing import List, Optional
+from json.decoder import JSONDecodeError
 from langchain.prompts import PromptTemplate
 from langchain_core.output_parsers import JsonOutputParser
 from langchain_core.runnables import RunnableParallel
@@ -121,9 +122,21 @@ def execute(self, state: dict) -> dict:
                 partial_variables={"context": doc, "format_instructions": format_instructions}
             )
             chain = prompt | self.llm_model
+            raw_response = str((prompt | self.llm_model).invoke({"question": user_prompt}))
+
             if output_parser:
-                chain = chain | output_parser
-            answer =  chain.invoke({"question": user_prompt})
+                try:
+                    answer = output_parser.parse(raw_response)
+                except JSONDecodeError:
+                    lines = raw_response.split('\n')
+                    if lines[0].strip().startswith('```'):
+                        lines = lines[1:]
+                    if lines[-1].strip().endswith('```'):
+                        lines = lines[:-1]
+                    cleaned_response = '\n'.join(lines)
+                    answer = output_parser.parse(cleaned_response)
+            else:
+                answer = raw_response
 
             state.update({self.output[0]: answer})
             return state