update: saving file upon exit

index.html

@@ -109,9 +109,6 @@
         <label for="nospam" class="pure-checkbox">
             <input id="nospam" type="checkbox"/> Avoid spamming
         </label>
-        <label for="save" class="pure-checkbox">
-            <input id="save" type="checkbox" checked/> Save to file
-        </label>
         <label for="logs" class="pure-checkbox">
             <input id="logs" class="local-only" type="checkbox"/> Show logs
         </label>
@@ -190,7 +187,6 @@
 
 <script type="module">
 import { default as $, LogRecord, Rpc2 } from '/';
-if (performance.getEntriesByType('navigation')[0].type === 'reload') await Rpc2.invoke('exit');
 
 let limit = 0;
 let length = 0;
@@ -202,6 +198,13 @@ let writable = null;
 let filereader = null;
 let subcategories = [];
 
+window.addEventListener('beforeunload', (e) => {
+    writable?.abort().catch(() => void 0);
+    Rpc2.notify('exit');
+    e.preventDefault();
+    e.returnValue = '';
+});
+
 let { locales, mapping, parameters } = await Rpc2.invoke('context');
 let account = new String(parameters.account);
 let name = account.split('@', 1).pop();
@@ -229,7 +232,7 @@ async function handlePrimaryButtonClick() {
                 reader.readAsArrayBuffer(file);
             }));
 
-            let [file, buffer] = await filereader().catch(() => []);
+            let [file, buffer] = await filereader().catch(e => alert('(ERROR) ' + new String(e ?? 'Unable to read data')));
             writable = await handle.createWritable().catch(() => null);
             limit = await Rpc2.invoke('ready', file.name, new Uint8Array(buffer).toBase64());
             $.get('#fileLabel').innerText = file.name;
@@ -238,7 +241,7 @@ async function handlePrimaryButtonClick() {
             break;
         case 'READY':
             let locale = $('#locale').value;
-            let options = { locale, mapping: new Object()};
+            let options = { locale, mapping: new Object(), writable: new Boolean(writable) };
 
             for (let element of $.all("input[type='number'].params")) {
                 parameters[element.id] = element.disabled ? null : element.valueAsNumber;