add: functionality to add code from url and github gists

pages/index.js

@@ -4,7 +4,7 @@ import LoadLFortran from "../components/LoadLFortran";
 import preinstalled_programs from "../utils/preinstalled_programs";
 import { useIsMobile } from "../components/useIsMobile";
 
-import { useState } from "react";
+import { useState, useEffect } from "react";
 import { Col, Row, Spin } from "antd";
 import { notification } from "antd";
 import { LoadingOutlined } from "@ant-design/icons";
@@ -49,6 +49,40 @@ export default function Home() {
 
     const myHeight = ((!isMobile) ? "calc(100vh - 170px)" : "calc(50vh - 85px)");
 
+    useEffect(() => {
+           fetchData();
+      }, []);
+
+      useEffect(() => {
+            if(moduleReady){handleUserTabChange("STDOUT"); }
+    }, [moduleReady]);
+
+    async function fetchData() {
+        const url = window.location.search;
+        const gist = "https://gist.githubusercontent.com/";
+        const urlParams = new URLSearchParams(url);
+
+        if (urlParams.get("code")) {
+            setSourceCode(decodeURIComponent(urlParams.get("code")));
+        } else if (urlParams.get("gist")) {
+            const gistUrl = gist + urlParams.get("gist") + "/raw/";
+            fetch(gistUrl)
+                .then((response) => response.text())
+                .then((data) => {
+                setSourceCode(data);
+                openNotification(
+                    "Source Code loaded from gist.",
+                    "bottomRight"
+                );
+
+                })
+                .catch((error) => {
+                    console.error("Error fetching data:", error);
+                    openNotification("error fetching .", "bottomRight");
+                });
+        }
+    }
+
     async function handleUserTabChange(key) {
         if (key == "STDOUT") {
             if(sourceCode.trim() === ""){