Caption messages by id

public/scripts/extensions/caption/index.js

@@ -257,6 +257,19 @@ async function onSelectImage(e, prompt, quiet) {
         return '';
     }
 
+    const caption = await getCaptionForFile(file, prompt, quiet);
+    form && form.reset();
+    return caption;
+}
+
+/**
+ * Gets a caption for an image file.
+ * @param {File} file Input file
+ * @param {string} prompt Caption prompt
+ * @param {boolean} quiet Suppresses sending a message
+ * @returns {Promise<string>} Generated caption
+ */
+async function getCaptionForFile(file, prompt, quiet) {
     try {
         setSpinnerIcon();
         const context = getContext();
@@ -276,7 +289,6 @@ async function onSelectImage(e, prompt, quiet) {
         return '';
     }
     finally {
-        form && form.reset();
         setImageIcon();
     }
 }
@@ -291,9 +303,26 @@ function onRefineModeInput() {
  * @param {object} args Named parameters
  * @param {string} prompt Caption prompt
  */
-function captionCommandCallback(args, prompt) {
+async function captionCommandCallback(args, prompt) {
-    return new Promise(resolve => {
     const quiet = isTrueBoolean(args?.quiet);
+    const id = args?.id;
+
+    if (!isNaN(Number(id))) {
+        const message = getContext().chat[id];
+        if (message?.extra?.image) {
+            try {
+                const fetchResult = await fetch(message.extra.image);
+                const blob = await fetchResult.blob();
+                const file = new File([blob], 'image.jpg', { type: blob.type });
+                return await getCaptionForFile(file, prompt, quiet);
+            } catch (error) {
+                toastr.error('Failed to get image from the message. Make sure the image is accessible.');
+                return '';
+            }
+        }
+    }
+
+    return new Promise(resolve => {
         const input = document.createElement('input');
         input.type = 'file';
         input.accept = 'image/*';
@@ -502,6 +531,9 @@ jQuery(function () {
             new SlashCommandNamedArgument(
                 'quiet', 'suppress sending a captioned message', [ARGUMENT_TYPE.BOOLEAN], false, false, 'false', ['true', 'false'],
             ),
+            new SlashCommandNamedArgument(
+                'id', 'get image from a message with this ID', [ARGUMENT_TYPE.NUMBER], false, false,
+            ),
         ],
         unnamedArgumentList: [
             new SlashCommandArgument(
@@ -515,6 +547,9 @@ jQuery(function () {
             <div>
                 Only multimodal sources support custom prompts.
             </div>
+            <div>
+                Provide a message ID to get an image from a message instead of uploading one.
+            </div>
             <div>
                 Set the "quiet" argument to true to suppress sending a captioned message, default: false.
             </div>