[WEB-1024] fix: textarea component auto-resize (#4221)

* chore: updated resize hook logic

* fix: page title overflow issue

* chore: add length validation to page title

packages/ui/src/form-fields/textarea.tsx

@@ -1,6 +1,8 @@
-import * as React from "react";
+import React, { useRef } from "react";
 // helpers
 import { cn } from "../../helpers";
+// hooks
+import { useAutoResizeTextArea } from "../hooks/use-auto-resize-textarea";
 
 export interface TextAreaProps extends React.TextareaHTMLAttributes<HTMLTextAreaElement> {
   mode?: "primary" | "transparent";
@@ -8,21 +10,6 @@ export interface TextAreaProps extends React.TextareaHTMLAttributes<HTMLTextArea
   className?: string;
 }
 
-// Updates the height of a <textarea> when the value changes.
-const useAutoSizeTextArea = (textAreaRef: HTMLTextAreaElement | null, value: any) => {
-  React.useEffect(() => {
-    if (textAreaRef) {
-      // We need to reset the height momentarily to get the correct scrollHeight for the textarea
-      textAreaRef.style.height = "0px";
-      const scrollHeight = textAreaRef.scrollHeight;
-
-      // We then set the height directly, outside of the render loop
-      // Trying to set this with state or a ref will product an incorrect value.
-      textAreaRef.style.height = scrollHeight + "px";
-    }
-  }, [textAreaRef, value]);
-};
-
 const TextArea = React.forwardRef<HTMLTextAreaElement, TextAreaProps>((props, ref) => {
   const {
     id,
@@ -35,10 +22,10 @@ const TextArea = React.forwardRef<HTMLTextAreaElement, TextAreaProps>((props, re
     className = "",
     ...rest
   } = props;
-
-  const textAreaRef = React.useRef<any>(ref);
-
-  useAutoSizeTextArea(textAreaRef?.current, value);
+  // refs
+  const textAreaRef = useRef<any>(ref);
+  // auto re-size
+  useAutoResizeTextArea(textAreaRef);
 
   return (
     <textarea

packages/ui/src/hooks/use-auto-resize-textarea.ts

@@ -0,0 +1,24 @@
+import { useEffect } from "react";
+
+export const useAutoResizeTextArea = (textAreaRef: React.RefObject<HTMLTextAreaElement>) => {
+  useEffect(() => {
+    const textArea = textAreaRef.current;
+    if (!textArea) return;
+
+    const resizeTextArea = () => {
+      textArea.style.height = "auto";
+      const computedHeight = textArea.scrollHeight + "px";
+      textArea.style.height = computedHeight;
+    };
+
+    const handleInput = () => resizeTextArea();
+
+    // resize on mount
+    resizeTextArea();
+
+    textArea.addEventListener("input", handleInput);
+    return () => {
+      textArea.removeEventListener("input", handleInput);
+    };
+  }, [textAreaRef]);
+};

web/components/pages/editor/editor-body.tsx

@@ -109,7 +109,7 @@ export const PageEditorBody: React.FC<Props> = observer((props) => {
         })}
       >
         <div className="h-full w-full flex flex-col gap-y-7 overflow-y-auto overflow-x-hidden">
-          <div className="w-full flex-shrink-0 ml-5">
+          <div className="relative w-full flex-shrink-0 pl-5">
             <PageEditorTitle
               editorRef={editorRef}
               title={pageTitle}

web/components/pages/editor/title.tsx

@@ -1,8 +1,11 @@
+import { useState } from "react";
 import { observer } from "mobx-react";
 // editor
 import { EditorRefApi } from "@plane/document-editor";
 // ui
 import { TextArea } from "@plane/ui";
+// helpers
+import { cn } from "@/helpers/common.helper";
 
 type Props = {
   editorRef: React.RefObject<EditorRefApi>;
@@ -13,27 +16,51 @@ type Props = {
 
 export const PageEditorTitle: React.FC<Props> = observer((props) => {
   const { editorRef, readOnly, title, updateTitle } = props;
+  // states
+  const [isLengthVisible, setIsLengthVisible] = useState(false);
 
   return (
     <>
       {readOnly ? (
         <h6 className="-mt-2 break-words bg-transparent text-4xl font-bold">{title}</h6>
       ) : (
-        <TextArea
-          onChange={(e) => updateTitle(e.target.value)}
-          className="-mt-2 w-full bg-custom-background text-4xl font-bold outline-none p-0 border-none resize-none rounded-none"
-          style={{
-            lineHeight: "1.2",
-          }}
-          placeholder="Untitled Page"
-          onKeyDown={(e) => {
-            if (e.key === "Enter") {
-              e.preventDefault();
-              editorRef.current?.setFocusAtPosition(0);
-            }
-          }}
-          value={title}
-        />
+        <>
+          <TextArea
+            onChange={(e) => updateTitle(e.target.value)}
+            className="-mt-2 w-full bg-custom-background text-4xl font-bold outline-none p-0 border-none resize-none rounded-none"
+            style={{
+              lineHeight: "1.2",
+            }}
+            placeholder="Untitled Page"
+            onKeyDown={(e) => {
+              if (e.key === "Enter") {
+                e.preventDefault();
+                editorRef.current?.setFocusAtPosition(0);
+              }
+            }}
+            value={title}
+            maxLength={255}
+            onFocus={() => setIsLengthVisible(true)}
+            onBlur={() => setIsLengthVisible(false)}
+          />
+          <div
+            className={cn(
+              "pointer-events-none absolute bottom-1 right-1 z-[2] rounded bg-custom-background-100 p-0.5 text-xs text-custom-text-200 opacity-0 transition-opacity",
+              {
+                "opacity-100": isLengthVisible,
+              }
+            )}
+          >
+            <span
+              className={cn({
+                "text-red-500": title.length === 0 || title.length > 255,
+              })}
+            >
+              {title.length}
+            </span>
+            /255
+          </div>
+        </>
       )}
     </>
   );