updated expiry date fetch

src/pages/nse-options/index.tsx

@@ -44,7 +44,10 @@ const NseFlatDataOptions = observer(({ initialData, initialStock }: { initialDat
 
   useEffect(() => {
     const expiryDateStore = initializeExpiryDateStore();
-    expiryDateStore.fetchExpiryDates().then(() => {
+
+    // Since fetchExpiryDates() is removed, we use fetchExpiryDatesForSymbol
+    // Default to 'NIFTY' or whatever symbol you want to start with
+    expiryDateStore.fetchExpiryDatesForSymbol('NIFTY').then(() => {
       setExpiryDateStore(expiryDateStore);
       const firstExpiryDate = expiryDateStore.expiryDates[0] || '';
 
@@ -53,7 +56,7 @@ const NseFlatDataOptions = observer(({ initialData, initialStock }: { initialDat
 
       // Initialize DefaultStore
       const myDefaultStore = new DefaultStore();
-        myDefaultStore.setExpiryDate(firstExpiryDate);
+      myDefaultStore.setExpiryDate(firstExpiryDate);
 
       // Now that we have the expiry date, we can fetch the data
       const nseFetchStore = initializeNseFetchStore(myDefaultStore, expiryDateStore, initialData);
@@ -63,6 +66,7 @@ const NseFlatDataOptions = observer(({ initialData, initialStock }: { initialDat
         setIsLoading(false);
       });
     });
+
   }, [initialData, initialStock]); // Removed store from the dependency array
 
  useEffect(() => {
@@ -245,15 +249,19 @@ const NseFlatDataOptions = observer(({ initialData, initialStock }: { initialDat
             </div>
             <div>
             <DropDownListComponent
-              placeholder="Select Instrument"
-              dataSource={symbolStore?.symbolStore.symbols || []}
-              value="NIFTY"
-              change={(e) => {
-                const selectedSymbol = e.value as string;
-                store?.nseFetchStore.setSymbol(selectedSymbol);
-                expiryDateStore?.fetchExpiryDatesForSymbol(selectedSymbol);
-              }}
-            />
+                placeholder="Select Instrument"
+                dataSource={symbolStore?.symbolStore.symbols || []}
+                value="NIFTY"
+                change={(e) => {
+                  const selectedSymbol = e.value as string;
+                  store?.nseFetchStore.setSymbol(selectedSymbol);
+                  expiryDateStore?.fetchExpiryDatesForSymbol(selectedSymbol).then(() => {
+                    const firstExpiryDate = expiryDateStore.expiryDates[0] || '';
+                    setExpiryDate(firstExpiryDate);
+                    store?.nseFetchStore.setExpiryDate(firstExpiryDate);
+                  });
+                }}
+              />
             </div>
           </div>
 

src/stores/ExpiryDateStore.ts

@@ -1,60 +1,63 @@
 import { makeObservable, observable, action } from 'mobx';
 import axios from 'axios';
 
+// Caching utility, mimicking SWR's caching mechanism
+const cache = new Map();
+
+const fetcher = async (url: string) => {
+  const { data } = await axios.get(url);
+  return data;
+};
+
 export class ExpiryDateStore {
-  expiryDates: string[] = [];  // Initialized as an array
+  expiryDates: string[] = [];
   isLoading: boolean = false;
 
   constructor() {
     makeObservable(this, {
       expiryDates: observable,
       isLoading: observable,
       setExpiryDates: action,
-      fetchExpiryDates: action,
-      fetchExpiryDatesForSymbol: action, // Add this line
+      fetchExpiryDatesForSymbol: action,
     });
   }
 
   setExpiryDates(dates: string[]): void {
     this.expiryDates = dates;
   }
 
-  fetchExpiryDates = async () => {
+  fetchExpiryDatesForSymbol = async (symbol: string = "NIFTY") => {
     this.isLoading = true;
-
-    // Fetch expiry dates
-    const expiryResponse = await axios.get(`https://tradepodapisrv.azurewebsites.net/api/get-expiry/?symbol=NIFTY`);
-    const expiryData = expiryResponse.data;
-    if (expiryData && expiryData.expiry_dates) {
-      this.setExpiryDates(expiryData.expiry_dates);
-      console.log(this.expiryDates);  // Log the expiryDates
-    } else {
-      throw new Error('Expiry dates not found');
+
+    const url = `https://tradepodapisrv.azurewebsites.net/api/get-expiry/?symbol=${encodeURIComponent(symbol)}`;
+    console.log(`Generated URL for Symbol ${symbol}:`, url);
+
+    if (cache.has(url)) {
+      this.setExpiryDates(cache.get(url));
+      this.isLoading = false;
+      return;
     }
 
-    this.isLoading = false;
-  };
-
-  fetchExpiryDatesForSymbol = async (symbol: string) => {
-    this.isLoading = true;
-     // Define the API URL based on the environment
-  const API_URL = process.env.NODE_ENV === 'production' 
-  ? process.env.REACT_APP_API_URL_PRODUCTION 
-  : process.env.REACT_APP_API_URL_LOCAL;
-    // Fetch expiry dates for a specific symbol
-    const expiryResponse = await axios.get(`${API_URL}/api/get-expiry/?symbol=${encodeURIComponent(symbol)}`);
-    const expiryData = expiryResponse.data;
-    if (expiryData && expiryData.expiry_dates) {
-      this.setExpiryDates(expiryData.expiry_dates);
-      console.log(this.expiryDates);  // Log the expiryDates
-    } else {
-      throw new Error('Expiry dates not found');
+    try {
+      const data = await fetcher(url);
+
+      if (data?.expiry_dates?.length) {
+        this.setExpiryDates(data.expiry_dates);
+        cache.set(url, data.expiry_dates); // Cache the data
+        console.log(`Expiry Dates Stored for Symbol ${symbol}:`, this.expiryDates);
+      } else {
+        console.error(`Expiry dates not found for symbol: ${symbol}`);
+        this.setExpiryDates([]); // Clear the expiry dates
+      }
+    } catch (error) {
+      console.error(`Error fetching expiry dates for symbol: ${symbol}`, error);
+      this.setExpiryDates([]); // Clear the expiry dates in case of an error
+    } finally {
+      this.isLoading = false;
     }
-
-    this.isLoading = false;
   };
 }
 
 export const initializeExpiryDateStore = (): ExpiryDateStore => {
   return new ExpiryDateStore();
-};
+};

src/stores/NseFetchStore.ts

@@ -126,15 +126,16 @@ export class NseFetchStore {
   setExpiryDates(dates: string[]): void {
     this.expiryDates = dates;
   }
-
   fetchData = async (userSelectedStock: string = this.symbol || 'NIFTY', firstExpiryDate: string = this.expiryDate || '') => {
     this.isLoading = true;
 
-    // Define the API URL based on the environment
-    const API_URL = process.env.NODE_ENV === 'production' 
-      ? process.env.REACT_APP_API_URL_PRODUCTION 
-      : process.env.REACT_APP_API_URL_LOCAL;
-
+    // If we don't have an expiry date, log an error and stop further execution
+    if (!firstExpiryDate) {
+      console.error('Expiry date is not available.');
+      this.isLoading = false;
+      return [];
+    }
+
     try {
       const response = await axios.get(`https://tradepodapisrv.azurewebsites.net/api/option-chain-copy/?symbol=${encodeURIComponent(this.symbol)}&expiry_date=${encodeURIComponent(firstExpiryDate)}`);
       const data = response.data as NseApiResponse;
@@ -154,6 +155,7 @@ export class NseFetchStore {
       this.isLoading = false;
     }
   };
+
 
   dispose() {
     if (this.intervalId) {