feat: add highlight words feature for messages and user preferences

app/containers/markdown/components/Plain.tsx

@@ -1,19 +1,72 @@
-import React from 'react';
+import React, { useContext } from 'react';
 import { Text } from 'react-native';
 import { type Plain as PlainProps } from '@rocket.chat/message-parser';
 
 import { useTheme } from '../../../theme';
 import styles from '../styles';
+import MarkdownContext from '../contexts/MarkdownContext';
 
 interface IPlainProps {
 	value: PlainProps['value'];
 }
 
+const escapeRegExp = (s: string) => s.replace(/[.*+?^${}()|[\]\\]/g, '\\$&');
+
 const Plain = ({ value }: IPlainProps): React.ReactElement => {
-	const { colors } = useTheme();
+	const { colors, theme } = useTheme();
+	const { highlights = [] } = useContext(MarkdownContext as any);
+
+	const text = (value ?? '').toString();
+
+	if (!highlights || !highlights.length) {
+		return (
+			<Text accessibilityLabel={text} style={[styles.plainText, { color: colors.fontDefault }]}>
+				{text}
+			</Text>
+		);
+	}
+
+	// prepare case-insensitive set of highlight words
+	const words = highlights.map((w: any) => w?.toString().trim()).filter(Boolean);
+	if (!words.length) {
+		return (
+			<Text accessibilityLabel={text} style={[styles.plainText, { color: colors.fontDefault }]}>
+				{text}
+			</Text>
+		);
+	}
+
+	const wordsLower = new Set(words.map(w => w.toLowerCase()));
+	// build regex to split and keep matched parts; guard pattern
+	const pattern = words.map(escapeRegExp).filter(Boolean).join('|');
+	if (!pattern) {
+		return (
+			<Text accessibilityLabel={text} style={[styles.plainText, { color: colors.fontDefault }]}>
+				{text}
+			</Text>
+		);
+	}
+	const re = new RegExp(`(${pattern})`, 'ig');
+	const parts = text.split(re);
+
+	// use red highlight for matched words (theme-aware tokens)
+	const bg = colors.statusBackgroundDanger ?? '#FFC1C9';
+	const matchTextColor = colors.statusFontDanger ?? colors.fontDefault;
+
 	return (
-		<Text accessibilityLabel={value} style={[styles.plainText, { color: colors.fontDefault }]}>
-			{value}
+		<Text accessibilityLabel={text} style={[styles.plainText, { color: colors.fontDefault }]}> 
+			{parts.map((part, i) => {
+				if (!part) return null;
+				const isMatch = wordsLower.has(part.toLowerCase());
+				if (isMatch) {
+					return (
+						<Text key={`h-${i}`} style={{ backgroundColor: bg, color: matchTextColor }}>
+							{part}
+						</Text>
+					);
+				}
+				return <Text key={`p-${i}`}>{part}</Text>;
+			})}
 		</Text>
 	);
 };

app/containers/markdown/contexts/MarkdownContext.ts

@@ -10,6 +10,7 @@ interface IMarkdownContext {
 	navToRoomInfo?: Function;
 	getCustomEmoji?: Function;
 	onLinkPress?: Function;
+	highlights?: string[];
 }
 
 const defaultState = {
@@ -18,6 +19,8 @@ const defaultState = {
 	useRealName: false,
 	username: '',
 	navToRoomInfo: () => {}
+	,
+	highlights: []
 };
 
 const MarkdownContext = React.createContext<IMarkdownContext>(defaultState);

app/containers/markdown/index.tsx

@@ -32,6 +32,7 @@ interface IMarkdownProps {
 	navToRoomInfo?: Function;
 	onLinkPress?: TOnLinkPress;
 	isTranslated?: boolean;
+	highlights?: string[];
 }
 
 const Markdown: React.FC<IMarkdownProps> = ({
@@ -44,7 +45,8 @@ const Markdown: React.FC<IMarkdownProps> = ({
 	username = '',
 	getCustomEmoji,
 	onLinkPress,
-	isTranslated
+	isTranslated,
+	highlights = []
 }: IMarkdownProps) => {
 	if (!msg) return null;
 
@@ -67,7 +69,8 @@ const Markdown: React.FC<IMarkdownProps> = ({
 					username,
 					navToRoomInfo,
 					getCustomEmoji,
-					onLinkPress
+					onLinkPress,
+					highlights
 				}}>
 				{tokens?.map(block => {
 					switch (block.type) {

app/containers/message/Content.tsx

@@ -67,6 +67,7 @@ const Content = React.memo(
 					useRealName={props.useRealName}
 					onLinkPress={onLinkPress}
 					isTranslated={props.isTranslated}
+					highlights={props.highlights}
 				/>
 			);
 		}

app/containers/message/index.tsx

@@ -63,6 +63,7 @@ interface IMessageContainerProps {
 	isPreview?: boolean;
 	dateSeparator?: Date | string | null;
 	showUnreadSeparator?: boolean;
+	highlights?: string[];
 }
 
 interface IMessageContainerState {
@@ -375,11 +376,12 @@ class MessageContainer extends React.Component<IMessageContainerProps, IMessageC
 			threadBadgeColor,
 			toggleFollowThread,
 			jumpToMessage,
-			highlighted,
+			highlighted: propHighlighted,
 			isBeingEdited,
 			isPreview,
 			showUnreadSeparator,
-			dateSeparator
+			dateSeparator,
+			highlights
 		} = this.props;
 		const {
 			id,
@@ -426,6 +428,10 @@ class MessageContainer extends React.Component<IMessageContainerProps, IMessageC
 
 		const canTranslateMessage = autoTranslateRoom && autoTranslateLanguage && autoTranslateMessage !== false && otherUserMessage;
 
+		const safeMessage = (message ?? '').toString();
+		const isHighlighted =
+			propHighlighted || (highlights && highlights.some(word => safeMessage.toLowerCase().includes(word.toLowerCase())));
+
 		return (
 			<MessageContext.Provider
 				value={{
@@ -499,7 +505,8 @@ class MessageContainer extends React.Component<IMessageContainerProps, IMessageC
 					navToRoomInfo={navToRoomInfo}
 					handleEnterCall={handleEnterCall}
 					blockAction={blockAction}
-					highlighted={highlighted}
+					highlighted={isHighlighted}
+					highlights={highlights}
 					comment={comment}
 					isTranslated={isTranslated}
 					isBeingEdited={isBeingEdited}

app/containers/message/interfaces.ts

@@ -70,6 +70,7 @@ export interface IMessageContent {
 	hasError: boolean;
 	isHeader: boolean;
 	isTranslated: boolean;
+	highlights?: string[];
 	pinned?: boolean;
 }
 

app/definitions/IUser.ts

@@ -112,6 +112,7 @@ export interface INotificationPreferences {
 	pushNotifications: TNotifications;
 	emailNotificationMode: 'mentions' | 'nothing';
 	language?: string;
+	highlights?: string[];
 }
 
 export interface IMessagePreferences {

app/i18n/locales/en.json

@@ -639,6 +639,12 @@
   "Please_enter_your_password": "Please enter your password",
   "Please_wait": "Please wait.",
   "Preferences": "Preferences",
+  "Highlight_Words": "Highlight words",
+  "Highlight_Words_Description": "Words to highlight in messages, separated by commas",
+  "Highlights": "Highlights",
+  "Highlights_Description": "Words to highlight in messages, separated by commas",
+  "Highlights_save_failed": "Failed to save highlights",
+  "Highlights_saved_successfully": "Highlights saved successfully",
   "Presence_Cap_Warning_Description": "Active connections have reached the limit for the workspace, thus the service that handles user status is disabled. It can be re-enabled manually in workspace settings.",
   "Presence_Cap_Warning_Title": "User status temporarily disabled",
   "Privacy_Policy": " Privacy policy",

app/views/RoomView/index.tsx

@@ -1373,6 +1373,7 @@ class RoomView extends React.Component<IRoomViewProps, IRoomViewState> {
 					isBeingEdited={isBeingEdited}
 					dateSeparator={dateSeparator}
 					showUnreadSeparator={showUnreadSeparator}
+					highlights={user.settings?.preferences?.highlights}
 				/>
 			);
 		}

app/views/UserPreferencesView/index.tsx

@@ -1,5 +1,5 @@
 import { type NativeStackNavigationProp } from '@react-navigation/native-stack';
-import React, { useEffect } from 'react';
+import React, { useEffect, useState, useRef } from 'react';
 import { useDispatch } from 'react-redux';
 
 import { setUser } from '../../actions/login';
@@ -10,11 +10,14 @@ import SafeAreaView from '../../containers/SafeAreaView';
 import * as List from '../../containers/List';
 import { getUserSelector } from '../../selectors/login';
 import { type ProfileStackParamList } from '../../stacks/types';
-import { saveUserPreferences } from '../../lib/services/restApi';
+import { saveUserPreferences, setUserPreferences, getUserPreferences } from '../../lib/services/restApi';
+import { showToast } from '../../lib/methods/helpers/showToast';
 import { useAppSelector } from '../../lib/hooks/useAppSelector';
 import ListPicker from './ListPicker';
 import Switch from '../../containers/Switch';
 import { type IUser } from '../../definitions';
+import { FormTextInput } from '../../containers/TextInput';
+import Button from '../../containers/Button';
 
 interface IUserPreferencesViewProps {
 	navigation: NativeStackNavigationProp<ProfileStackParamList, 'UserPreferencesView'>;
@@ -27,6 +30,16 @@ const UserPreferencesView = ({ navigation }: IUserPreferencesViewProps): JSX.Ele
 	const serverVersion = useAppSelector(state => state.server.version);
 	const dispatch = useDispatch();
 	const convertAsciiEmoji = settings?.preferences?.convertAsciiEmoji;
+	const initialHighlightRef = useRef(settings?.preferences?.highlights?.join(', ') || '');
+	const [highlights, setHighlights] = useState(initialHighlightRef.current);
+	const [dirty, setDirty] = useState(false);
+
+	useEffect(() => {
+		const initial = settings?.preferences?.highlights?.join(', ') || '';
+		initialHighlightRef.current = initial;
+		setHighlights(initial);
+		setDirty(false);
+	}, [settings?.preferences?.highlights]);
 
 	useEffect(() => {
 		navigation.setOptions({
@@ -42,8 +55,10 @@ const UserPreferencesView = ({ navigation }: IUserPreferencesViewProps): JSX.Ele
 
 	const toggleMessageParser = async (value: boolean) => {
 		try {
-			dispatch(setUser({ enableMessageParserEarlyAdoption: value }));
-			await saveUserPreferences({ id, enableMessageParserEarlyAdoption: value });
+			// optimistic update
+			dispatch(setUser({ settings: { ...settings, preferences: { ...settings?.preferences, enableMessageParserEarlyAdoption: value } } } as Partial<IUser>));
+			// send properly shaped payload (userId separate)
+			await setUserPreferences(id, { enableMessageParserEarlyAdoption: value });
 		} catch (e) {
 			log(e);
 		}
@@ -58,10 +73,77 @@ const UserPreferencesView = ({ navigation }: IUserPreferencesViewProps): JSX.Ele
 		}
 	};
 
+	const saveHighlights = async (value: string) => {
+			try {
+				const words = value.split(',').map(w => w.trim()).filter(w => w);
+				const current = Array.isArray(settings?.preferences?.highlights)
+					? settings.preferences.highlights.map((s: string) => (s || '').trim())
+					: [];
+				const unchanged = JSON.stringify(current) === JSON.stringify(words);
+				if (unchanged && !dirty) {
+					// No change, skip network/save and toasts
+					return;
+				}
+
+				// optimistic update: merge highlights into existing preferences
+				dispatch(setUser({
+					settings: {
+						...settings,
+						preferences: {
+							...settings?.preferences,
+							highlights: words
+						}
+					}
+				} as Partial<IUser>));
+
+				// attempt save and capture server response or error
+				let saveRes: any;
+				try {
+					saveRes = await saveUserPreferences({ highlights: words });
+					log({ saveUserPreferencesResponse: saveRes });
+				} catch (err) {
+					log(err);
+					showToast(I18n.t('Highlights_save_failed'));
+					return;
+				}
+
+				// verify server-side saved value and inform the user; normalize values to avoid ordering/spacing mismatches
+				try {
+					const result = await getUserPreferences(id);
+					log({ getUserPreferencesResponse: result });
+					if (result?.success && result?.preferences) {
+						const saved: string[] = Array.isArray(result.preferences.highlights)
+							? result.preferences.highlights.map((s: string) => (s || '').trim().toLowerCase())
+							: [];
+						const expected = words.map(w => w.trim().toLowerCase());
+						const sortA = [...saved].sort();
+						const sortB = [...expected].sort();
+						if (JSON.stringify(sortA) === JSON.stringify(sortB)) {
+							initialHighlightRef.current = value;
+							setDirty(false);
+							showToast(I18n.t('Highlights_saved_successfully'));
+						} else {
+							log({ highlightsMismatch: { saved, expected } });
+							showToast(I18n.t('Highlights_save_failed'));
+						}
+					} else {
+						showToast(I18n.t('Highlights_save_failed'));
+					}
+				} catch (err) {
+					log(err);
+					showToast(I18n.t('Highlights_save_failed'));
+				}
+			} catch (e) {
+				log(e);
+				showToast(I18n.t('Highlights_save_failed'));
+			}
+		};
+
 	const setAlsoSendThreadToChannel = async (param: { [key: string]: string }, onError: () => void) => {
 		try {
 			await saveUserPreferences(param);
-			dispatch(setUser(param));
+			// optimistic update merging into preferences
+			dispatch(setUser({ settings: { ...settings, preferences: { ...settings?.preferences, ...param } } } as Partial<IUser>));
 		} catch (e) {
 			log(e);
 			onError();
@@ -116,6 +198,43 @@ const UserPreferencesView = ({ navigation }: IUserPreferencesViewProps): JSX.Ele
 					/>
 					<List.Separator />
 				</List.Section>
+				<List.Section>
+					<List.Separator />
+					<List.Item title='Highlights' testID='preferences-view-highlights' />
+					<List.Separator />
+					<FormTextInput
+						value={highlights}
+						onChangeText={value => {
+						setHighlights(value);
+						setDirty(value !== initialHighlightRef.current);
+					}}
+						onBlur={() => {
+						// Only save if dirty or changed
+						const words = highlights.split(',').map(w => w.trim()).filter(w => w);
+						const current = Array.isArray(settings?.preferences?.highlights)
+							? settings.preferences.highlights.map((s: string) => (s || '').trim())
+							: [];
+						const unchanged = JSON.stringify(current) === JSON.stringify(words);
+						if (!dirty && unchanged) return;
+						saveHighlights(highlights);
+					}}
+						placeholder={I18n.t('Highlight_Words_Placeholder')}
+					/>
+					{dirty ? (
+						<>
+							<List.Separator />
+							<Button
+								title={I18n.t('Save')}
+								small
+								onPress={() => saveHighlights(highlights)}
+								testID='preferences-view-highlights-save'
+								style={{ alignSelf: 'center', marginTop: 15}}
+							/>
+						</>
+					) : null}
+					<List.Separator />
+					<List.Info info='Highlights_Description' />
+				</List.Section>
 			</List.Container>
 		</SafeAreaView>
 	);