Update frontend for nicer error handling from backend

src/lib/page.py

@@ -32,59 +32,31 @@ def header():
 
 def sidebar():
     st.sidebar.header("Options")
-
-    network = st.sidebar.radio("env", ("mainnet-beta", "devnet"))
-    st.session_state[NETWORK_STATE_KEY] = network
-
-    url = os.getenv("RPC_URL", "")
-    rpc = st.sidebar.text_input("RPC URL", value=url)
-    if network == "mainnet-beta" and rpc == "":
-        rpc = os.getenv("ANCHOR_PROVIDER_URL", "")
-    st.session_state[RPC_STATE_KEY] = rpc
-
-    if VAT_STATE_KEY not in st.session_state:
-        st.session_state[VAT_STATE_KEY] = None
-    st.sidebar.write(
-        f"Have VAT? {'✅' if st.session_state[VAT_STATE_KEY] is not None else 'Not Loaded'} "
-    )
-
-    metadata = api("metadata", "", as_json=True)
-    pickle_file = metadata["pickle_file"]
-    pickle_file = pickle_file.split("/")[-1]
-    timestamp = pickle_file.split("-")[1:]
-    timestamp = datetime.strptime(" ".join(timestamp), "%Y %m %d %H %M %S")
-    time_ago = datetime.now() - timestamp
-    time_ago_str = humanize.precisedelta(time_ago, minimum_unit="minutes")
-    st.sidebar.write(f"Last snapshot taken at: {timestamp} ({time_ago_str} ago)")
-
-
-def needs_rpc_and_vat(page_callable: callable):
+    try:
+        metadata = api("metadata", "", as_json=True)
+        pickle_file = metadata["pickle_file"]
+        pickle_file = pickle_file.split("/")[-1]
+        timestamp = pickle_file.split("-")[1:]
+        timestamp = datetime.strptime(" ".join(timestamp), "%Y %m %d %H %M %S")
+        time_ago = datetime.now() - timestamp
+        time_ago_str = humanize.precisedelta(time_ago, minimum_unit="minutes")
+        st.sidebar.write(f"Last snapshot taken at: {timestamp} ({time_ago_str} ago)")
+    except Exception as e:
+        st.sidebar.write("# Unable to reach backend")
+
+
+def needs_backend(page_callable: callable):
     """
     Decorator to add a guard to a page function
     """
 
     def page_with_guard():
-        rpc = st.session_state[RPC_STATE_KEY]
-        if rpc == "🤫" or rpc == "" or rpc is None:
-            st.warning("Please enter a Solana RPC URL in the sidebar")
+        try:
+            api("metadata", "", as_json=True)
+        except Exception as e:
+            st.error("Sorry, unable to reach backend")
             return
 
-        vat = st.session_state[VAT_STATE_KEY]
-        if vat is None:
-            drift_client = DriftClient(
-                AsyncClient(rpc),
-                Wallet.dummy(),
-                account_subscription=AccountSubscriptionConfig("cached"),
-            )
-            loop: AbstractEventLoop = asyncio.new_event_loop()
-            newest_snapshot = load_newest_files(os.getcwd() + "/pickles")
-            start_load_vat = time.time()
-            vat = loop.run_until_complete(load_vat(drift_client, newest_snapshot))
-            st.session_state["vat"] = vat
-            print(f"loaded vat in {time.time() - start_load_vat}")
-            st.session_state[VAT_STATE_KEY] = vat
-            loop.close()
-
         page_callable()
 
     return page_with_guard

src/main.py

@@ -1,6 +1,6 @@
 from dotenv import load_dotenv
 from lib.page import header
-from lib.page import needs_rpc_and_vat
+from lib.page import needs_backend
 from lib.page import sidebar
 from page.asset_liability import asset_liab_matrix_page
 from page.backend import backend_page
@@ -28,37 +28,37 @@
                 icon=":material/home:",
             ),
             st.Page(
-                orderbook_page,
+                needs_backend(orderbook_page),
                 url_path="orderbook",
                 title="Orderbook",
                 icon="📈",
             ),
             st.Page(
-                health_page,
+                needs_backend(health_page),
                 url_path="health",
                 title="Health",
                 icon="🏥",
             ),
             st.Page(
-                price_shock_page,
+                needs_backend(price_shock_page),
                 url_path="price-shock",
                 title="Price Shock",
                 icon="💸",
             ),
             st.Page(
-                asset_liab_matrix_page,
+                needs_backend(asset_liab_matrix_page),
                 url_path="asset-liab-matrix",
                 title="Asset-Liab Matrix",
                 icon="📊",
             ),
             st.Page(
-                plot_liquidation_curve,
+                needs_backend(plot_liquidation_curve),
                 url_path="liquidation-curves",
                 title="Liquidation Curves",
                 icon="🌊",
             ),
             st.Page(
-                backend_page,
+                needs_backend(backend_page),
                 url_path="backend",
                 title="Control Backend",
                 icon="🧪",