Obsidian-style foldable callout syntax (e.g. "![Info]- Title") ( Duplicate of #1060)

packages/remark-callouts/src/index.ts

@@ -1,2 +1,3 @@
 export * from "./lib/remark-callouts";
 export { default } from "./lib/remark-callouts";
+export { Callout } from "./lib/Callout";

packages/remark-callouts/src/lib/Callout.tsx

@@ -0,0 +1,20 @@
+import { useRef } from "react";
+
+const Callout = ({ className, children }) => {
+    // If it's not a foldable callout, just render it as a blockquote
+    if (!className.includes("callout-foldable")) {
+        return <blockquote className={className}>{children}</blockquote>;
+    }
+
+    const elem = useRef(null);
+
+    const handleClick = () => {
+        elem.current.classList.toggle("callout-folded");
+    };
+
+    return (
+        <blockquote className={className} ref={elem} onClick={handleClick}>{children}</blockquote>
+    );
+};
+
+export { Callout };

packages/remark-callouts/src/lib/remark-callouts.ts

@@ -113,15 +113,15 @@ export const callouts: Plugin = function (providedConfig?: Partial<Config>) {
       const [t, ...rest] = paragraph.children;
 
       const regex = new RegExp(
-        `^\\[!(?<keyword>(.*?))\\][\t\f ]?(?<title>.*?)$`,
+        `^\\[!(?<keyword>(.*?))\\](?<foldChar>[+-]?)[\t\f ]?(?<title>.*?)$`,
         "gi"
       );
       const m = regex.exec(t.value);
 
       // if no callout syntax, forget about it.
       if (!m) return;
 
-      const [key, title] = [m.groups?.keyword, m.groups?.title];
+      const [key, foldChar, title] = [m.groups?.keyword, m.groups?.foldChar, m.groups?.title];
 
       // if there's nothing inside the brackets, is it really a callout ?
       if (!key) return;
@@ -236,12 +236,17 @@ export const callouts: Plugin = function (providedConfig?: Partial<Config>) {
       blockquote.children.unshift(titleNode as BlockContent);
 
       // Add classes for the callout block
+      const classList = [formatClassNameMap(config.classNameMaps.block)(keyword.toLowerCase())]
+      if (foldChar) {
+        classList.push('callout-foldable')
+        if (foldChar === '-') {
+          classList.push('callout-folded')
+        }
+      }
       blockquote.data = config.dataMaps.block({
         ...blockquote.data,
         hProperties: {
-          className: formatClassNameMap(config.classNameMaps.block)(
-            keyword.toLowerCase()
-          ),
+          className: classList.join(" "),
           style: `border-left-color:${entry?.color};`,
         },
       });

packages/remark-callouts/styles.css

@@ -23,6 +23,7 @@
   align-items: center;
   padding: 10px;
   gap: 10px;
+  position: relative;
 }
 
 .callout-title > strong {
@@ -62,3 +63,40 @@ p:after {
 p:after {
   display: none;
 }
+
+blockquote.callout-foldable {
+  cursor: pointer;
+  display: grid;
+  grid-template-rows: min-content 1fr;
+  transition: all 0.3s ease-in-out; 
+}
+
+blockquote.callout-foldable.callout-folded {
+  grid-template-rows: min-content 0fr;
+}
+
+blockquote.callout-foldable .callout-content {
+  overflow: hidden;
+  padding: 0px 10px;
+}
+
+blockquote.callout-foldable .callout-title strong::after {
+  content: "";
+  display: inline-block;
+  height: 10px;
+  width: 10px;
+  border-style: solid;
+  border-width: 0 3px 3px 0;
+  border-color: var(--tw-prose-body);
+  position: absolute;
+  top: 50%;
+  right: 1em;
+  transform: translateY(-50%) rotate(45deg);
+  transform-origin: center;
+  transition: all 0.3s ease-in-out;
+}
+
+blockquote.callout-foldable.callout-folded .callout-title strong::after {
+  transform: translateY(-50%) rotate(-45deg);
+  transform-origin: center;
+}

packages/remark-callouts/tsconfig.lib.json

@@ -7,7 +7,8 @@
     "types": ["node"],
     "moduleResolution": "node",
     "esModuleInterop": true,
-    "forceConsistentCasingInFileNames": true
+    "forceConsistentCasingInFileNames": true,
+    "jsx": "react-jsx"
   },
   "exclude": ["**/*.spec.ts", "**/*.test.ts"],
   "include": ["src/**/*.ts"]