save code to localstorage

frontend/app.js

@@ -39,7 +39,24 @@ function base64Decode(bytes) {
   return new TextDecoder().decode(base64ToBytes(bytes));
 }
 
+function debounce(func, timeout = 300){
+  let timer;
+  return (...args) => {
+    clearTimeout(timer);
+    timer = setTimeout(() => { func.apply(this, args); }, timeout);
+  };
+}
+
+function saveToStorage(code) {
+  if (code.length) {
+    localStorage.setItem("code", code);
+  } else {
+    localStorage.removeItem("code");
+  }
+}
+
 let jar = CodeJar(document.querySelector('.editor'), highlight)
+jar.onUpdate(debounce(saveToStorage));
 const defaultCode = `use fmt;
 
 export fn main() void = {
@@ -55,9 +72,13 @@ export fn main() void = {
 	};
 };`;
 
+let savedCode = localStorage.getItem("code");
 if (location.hash) {
   let code = base64Decode(location.hash.substr(1));
   jar.updateCode(code)
+
+} else if (savedCode && savedCode.length) {
+  jar.updateCode(savedCode);
 } else {
   jar.updateCode(defaultCode);
 }

frontend/index.html

@@ -35,10 +35,12 @@
       <span id="htmx-indicator">
             <svg width="1em" height="1em" viewBox="0 0 24 24" xmlns="http://www.w3.org/2000/svg"><path d="M12,4a8,8,0,0,1,7.89,6.7A1.53,1.53,0,0,0,21.38,12h0a1.5,1.5,0,0,0,1.48-1.75,11,11,0,0,0-21.72,0A1.5,1.5,0,0,0,2.62,12h0a1.53,1.53,0,0,0,1.49-1.3A8,8,0,0,1,12,4Z"><animateTransform attributeName="transform" type="rotate" dur="0.75s" values="0 12 12;360 12 12" repeatCount="indefinite"/></path></svg>
       </span>
-      <span id="status" class="status"></span>
+      <span id="status" class="status">
+        <noscript>Sorry, this playground requires JavaScript. :(</noscript>
+      </span>
     </section>
     <section class="code">
-      <div class="editor language-c">Sorry, this playground requires JavaScript. :(</div>
+      <div class="editor language-c"></div>
 
       <div class="code-output">
         <div class="std-output">