update app.py

app.py

@@ -22,7 +22,7 @@ m = st.markdown(
     unsafe_allow_html=True,
 )
 
-# Authenticate and initialize Earth Engine
+# Initialize Earth Engine credentials
 earthengine_credentials = os.environ.get("EE_Authentication")
 
 # Initialize Earth Engine with secret credentials
@@ -57,27 +57,46 @@ custom_formula = ""
 if index_choice == 'Custom Formula':
     custom_formula = st.text_input("Enter Custom Formula (e.g., 'B5 - B4 / B5 + B4')")
 
+# Initialize session state for storing results and map (if not already done)
+if 'results' not in st.session_state:
+    st.session_state.results = []  # Initialize results list
+if 'last_params' not in st.session_state:
+    st.session_state.last_params = {}  # Initialize last_params
+if 'map_data' not in st.session_state:
+    st.session_state.map_data = None  # Initialize map_data for storing map object
+
+# Function to check if parameters have changed
+def parameters_changed():
+    return (
+        st.session_state.last_params.get('main_selection') != main_selection or
+        st.session_state.last_params.get('sub_selection') != sub_selection or
+        st.session_state.last_params.get('index_choice') != index_choice or
+        st.session_state.last_params.get('start_date_str') != start_date_str or
+        st.session_state.last_params.get('end_date_str') != end_date_str
+    )
+
+# If parameters have changed, reset the results
+if parameters_changed():
+    st.session_state.results = []  # Clear the previous results
+    # Update the last parameters to the current ones
+    st.session_state.last_params = {
+        'main_selection': main_selection,
+        'sub_selection': sub_selection,
+        'index_choice': index_choice,
+        'start_date_str': start_date_str,
+        'end_date_str': end_date_str
+    }
+
 # Function to read points from CSV with enhanced error handling
 def read_csv(file_path):
     try:
-        # Check if file is empty
         file_content = file_path.getvalue().decode("utf-8")
         if not file_content.strip():
             raise ValueError("Uploaded CSV file is empty.")
-        
-        # Attempt to read the CSV file with auto-detected delimiter
-        try:
-            df = pd.read_csv(file_path)
-        except pd.errors.ParserError:
-            st.error("Error parsing the CSV file. Ensure the file is in correct CSV format.")
-            return None
-
-        # Check if necessary columns ('latitude' and 'longitude') are present
+        df = pd.read_csv(file_path)
         if 'latitude' not in df.columns or 'longitude' not in df.columns:
             raise ValueError("CSV file must contain 'latitude' and 'longitude' columns.")
-        
         return df
-    
     except Exception as e:
         st.error(f"Error reading CSV file: {e}")
         return None
@@ -155,6 +174,9 @@ if file_upload:
         st.write("Map of Uploaded Points:")
         m.to_streamlit()
 
+        # Store the map in session_state
+        st.session_state.map_data = m
+
     # If there are polygons, display them on the map
     if polygons_df is not None:
         st.write("Preview of the uploaded polygons data:")
@@ -171,6 +193,9 @@ if file_upload:
         st.write("Map of Uploaded Polygons:")
         m.to_streamlit()
 
+        # Store the map in session_state
+        st.session_state.map_data = m
+
 # Function to perform index calculations (as before)
 def calculate_ndvi(image, geometry):
     ndvi = image.normalizedDifference(['B8', 'B4']).rename('NDVI')