added reinit button for query_engine, session state as well

app.py

@@ -166,12 +166,22 @@ with st.sidebar:
     st.subheader("Developer Information:")
     st.write("This app is developed and maintained by **@mohcineelharras**")
 
-# Define your app's tabs
-tab1, tab2, tab3 = st.tabs(["LLM only", "LLM RAG QA with database", "One single document Q&A"])
 if 'memory' not in st.session_state:
     st.session_state.memory = ""
-llm = load_llm_model()
-query_engine = load_emb_model()
+# LLM Model Loading
+if 'llm_model' not in st.session_state:
+    st.session_state.llm_model = load_llm_model()
+
+# Embedding Model Loading
+if 'emb_model' not in st.session_state:
+    st.session_state.emb_model = load_emb_model()
+
+# Use the models from session state
+llm = st.session_state.llm_model
+query_engine = st.session_state.emb_model
+
+# Define your app's tabs
+tab1, tab2, tab3 = st.tabs(["LLM only", "LLM RAG QA with database", "One single document Q&A"])
 
 # -----------------------------------LLM only--------------------------------------------- 
 
@@ -222,6 +232,9 @@ with tab2:
 
 with tab3:
     st.title("📝 One single document Q&A with Llama Index using local open llms")
+    if st.button('Reinitialize Query Engine', key='reinit_engine'):
+        query_engine = st.session_state.emb_model
+        st.write("Query engine reinitialized.")
     uploaded_file = st.file_uploader("Upload an File", type=("txt", "csv", "md","pdf"))
     question = st.text_input(
         "Ask something about the files",