Feed and Interactions for Your Social Network

introduction in this tutorial, you will learn how to build a social network feed with interactive features such as posts, comments, and likes using back4app as your backend service these features form the core of any social networking application, allowing users to share content and engage with other users back4app is a backend as a service (baas) platform built on parse server that provides developers with a robust infrastructure for creating scalable applications without managing server side code its real time database capabilities and built in user management make it an excellent choice for developing social networking applications by the end of this tutorial, you will have implemented a fully functional social feed that allows users to create posts with text and images view posts from other users in a feed like posts comment on posts view post details with comments you'll learn how to efficiently structure your database classes, implement real time updates, and create a responsive user interface that provides a seamless experience across devices prerequisites to complete this tutorial, you will need a back4app account you can sign up for a free account at back4app com https //www back4app com a back4app project set up you can learn how to create a new project by following our getting started with back4app guide https //www back4app com/docs/get started/welcome node js installed on your local machine basic knowledge of javascript and react js a working authentication system if you haven't set one up yet, follow our authentication system for social networks tutorial first familiarity with modern web development concepts (components, state management, etc ) back4gram project find here the complete code for a social network sample project built with back4app step 1 – understanding the data model before writing any code, it's important to understand the data model for our social network we'll need several parse classes to build our feed functionality post class the post class will store all post related information author a pointer to the user who created the post content the text content of the post image an optional image file likes a number representing how many likes the post has comments an array of pointers to comment objects (optional, can be queried separately) createdat automatically managed by back4app updatedat automatically managed by back4app comment class the comment class will store comments on posts author a pointer to the user who wrote the comment post a pointer to the post being commented on content the text content of the comment createdat automatically managed by back4app updatedat automatically managed by back4app like tracking we have two options for tracking likes simple counter store a likes count on each post (easier but less detailed) like records create a separate like class that tracks each individual like (more detailed) for this tutorial, we'll implement both approaches, starting with the simpler counter and then showing how to implement individual like records for more advanced features let's start by setting up these classes in back4app step 2 – setting up the data model in back4app in this step, you will create the necessary classes in your back4app database creating the post class log in to your back4app dashboard and navigate to your project in the left sidebar, click on "database" to open the database browser click the "create a class" button at the top of the page in the modal that appears, enter "post" as the class name and select "custom" as the type then click "create class" \[image back4app create class modal with "post" entered as class name] now, add the following columns to your post class click "add column" create the following columns author (type pointer, target class user) content (type string) image (type file) likes (type number, default value 0) creating the comment class click "create a class" again enter "comment" as the class name and select "custom" as the type add the following columns author (type pointer, target class user) post (type pointer, target class post) content (type string) setting up class level permissions for security, let's set up appropriate permissions for our classes in the database browser, select the post class click on the "security" button configure permissions public read yes (anyone can view posts) public write no (only authenticated users can create posts) public add field no find, get, create, update, delete require user authentication repeat similar settings for the comment class now that we have our data model set up, let's implement the front end components for our social network feed the feed page is the heart of any social network it displays posts from users and allows for interaction let's create a feed component that fetches and displays posts create a file called src/pages/feedpage js import react, { usestate, useeffect, useref } from 'react'; import { usenavigate } from 'react router dom'; import { box, flex, vstack, heading, text, button, input, simplegrid, avatar, hstack, iconbutton, textarea, spinner, center, image, } from '@chakra ui/react'; import { link as routerlink } from 'react router dom'; import parse from 'parse/dist/parse min js'; import { toaster } from ' /components/ui/toaster'; function feedpage() { const \[searchquery, setsearchquery] = usestate(''); const \[newpostcontent, setnewpostcontent] = usestate(''); const \[posts, setposts] = usestate(\[]); const \[isloading, setisloading] = usestate(true); const \[isposting, setisposting] = usestate(false); const \[currentuser, setcurrentuser] = usestate(null); // new state variables for image upload const \[selectedimage, setselectedimage] = usestate(null); const \[imagepreview, setimagepreview] = usestate(null); const fileinputref = useref(null); const navigate = usenavigate(); // check if user is authenticated useeffect(() => { const checkauth = async () => { try { const user = await parse user current(); if (!user) { // redirect to login if not authenticated navigate('/login'); return; } setcurrentuser(user); } catch (error) { console error('error checking authentication ', error); navigate('/login'); } }; checkauth(); }, \[navigate]); // handle image selection const handleimagechange = (e) => { if (e target files && e target files\[0]) { const file = e target files\[0]; setselectedimage(file); // create a preview url const reader = new filereader(); reader onloadend = () => { setimagepreview(reader result); }; reader readasdataurl(file); } }; // clear selected image const handleclearimage = () => { setselectedimage(null); setimagepreview(null); if (fileinputref current) { fileinputref current value = ''; } }; // fetch posts useeffect(() => { const fetchposts = async () => { if (!currentuser) { console log('no current user, skipping post fetch'); return; } setisloading(true); console log('fetching posts for user ', currentuser id); try { // create a query for the post class const query = new parse query('post'); console log('created post query'); // include the user who created the post query include('author'); console log('including author in query'); // sort by creation date, newest first query descending('createdat'); // limit to 20 posts query limit(20); // execute the query console log('executing query '); const results = await query find(); console log('query results received ', results length, 'posts found'); // convert parse objects to plain objects const fetchedposts = \[]; for (let i = 0; i < results length; i++) { const post = results\[i]; try { const author = post get('author'); console log(`processing post ${i+1}/${results length}, author `, author ? author id 'null'); if (!author) { console warn(`post ${post id} has no author, skipping`); continue; } const postobj = { id post id, content post get('content'), author { id author id, username author get('username'), avatar author get('avatar') ? author get('avatar') url() null }, image post get('image') ? post get('image') url() null, likes post get('likes') || 0, createdat post get('createdat') }; fetchedposts push(postobj); } catch (posterror) { console error(`error processing post ${i+1} `, posterror); console error('post data ', post tojson()); } } console log('successfully processed', fetchedposts length, 'posts'); setposts(fetchedposts); } catch (error) { console error('error fetching posts ', error); console error('error details ', error code, error message); toaster create({ title 'error loading posts', description error message, type 'error', }); } finally { setisloading(false); console log('post loading completed'); } }; fetchposts(); }, \[currentuser, navigate]); // function to create a new post with image const handlecreatepost = async () => { if (!newpostcontent trim() && !selectedimage) return; setisposting(true); console log('creating new post '); try { // create a new post object const post = parse object extend('post'); const post = new post(); // set post data post set('content', newpostcontent); post set('author', currentuser); post set('likes', 0); // handle image upload if an image is selected if (selectedimage) { console log('uploading image '); const parsefile = new parse file(selectedimage name, selectedimage); await parsefile save(); post set('image', parsefile); console log('image uploaded successfully'); } console log('post object created, saving to database '); // save the post const savedpost = await post save(); console log('post saved successfully with id ', savedpost id); // add the new post to the state const newpost = { id savedpost id, content savedpost get('content'), author { id currentuser id, username currentuser get('username'), avatar currentuser get('avatar') ? currentuser get('avatar') url() null }, image savedpost get('image') ? savedpost get('image') url() null, likes 0, createdat savedpost get('createdat') }; console log('adding new post to state'); setposts(\[newpost, posts]); setnewpostcontent(''); setselectedimage(null); setimagepreview(null); toaster create({ title 'post created', description 'your post has been published successfully!', type 'success', }); } catch (error) { console error('error creating post ', error); console error('error details ', error code, error message); toaster create({ title 'error creating post', description error message, type 'error', }); } finally { setisposting(false); console log('post creation completed'); } }; // function to like a post const handlelikepost = async (postid) => { try { // get the post const query = new parse query('post'); const post = await query get(postid); // increment likes post increment('likes'); await post save(); // update the post in the state setposts(posts map(p => { if (p id === postid) { return { p, likes p likes + 1 }; } return p; })); } catch (error) { console error('error liking post ', error); toaster create({ title 'error', description 'could not like the post please try again ', type 'error', }); } }; // function to logout const handlelogout = async () => { try { await parse user logout(); navigate('/login'); } catch (error) { console error('error logging out ', error); } }; const handlesearchsubmit = (e) => { e preventdefault(); if (searchquery trim()) { navigate(`/search?q=${encodeuricomponent(searchquery)}`); } }; // format date const formatdate = (date) => { return new date(date) tolocalestring(); }; return ( \<flex direction="row" h="100vh"> {/ left sidebar (navigation) /} \<box w={\['0px', '250px']} bg="gray 700" p={4} display={\['none', 'block']} borderright="1px solid" bordercolor="gray 600" \> \<vstack align="stretch" spacing={4}> \<heading size="md">social network\</heading> \<button as={routerlink} to="/feed" variant="ghost" justifycontent="flex start"> home \</button> \<button as={routerlink} to="/search" variant="ghost" justifycontent="flex start"> search \</button> \<button as={routerlink} to="/messages" variant="ghost" justifycontent="flex start"> messages \</button> \<button as={routerlink} to="/profile" variant="ghost" justifycontent="flex start"> profile \</button> \<button onclick={handlelogout} variant="ghost" colorscheme="red" justifycontent="flex start"> logout \</button> \</vstack> \</box> {/ main content (feed) /} \<box flex="1" p={4} overflowy="auto"> \<form onsubmit={handlesearchsubmit}> \<input placeholder="search " value={searchquery} onchange={(e) => setsearchquery(e target value)} mb={4} /> \</form> {/ create post with image upload /} \<box border="1px solid" bordercolor="gray 600" p={4} borderradius="md" mb={6}> \<textarea placeholder="what's on your mind?" value={newpostcontent} onchange={(e) => setnewpostcontent(e target value)} mb={2} resize="none" /> {/ image preview /} {imagepreview && ( \<box position="relative" mb={2}> \<image src={imagepreview} alt="preview" maxh="200px" borderradius="md" /> \<button position="absolute" top="2" right="2" size="sm" colorscheme="red" onclick={handleclearimage} \> remove \</button> \</box> )} \<box> \<input type="file" accept="image/ " onchange={handleimagechange} style={{ display 'none' }} ref={fileinputref} id="image upload" /> \<button as="label" htmlfor="image upload" cursor="pointer" variant="outline" size="sm" mr={2} mb={0} \> 📷 add photo \</button> \</box> \<button colorscheme="blue" onclick={handlecreatepost} isloading={isposting} disabled={(!newpostcontent trim() && !selectedimage) || isposting} \> post \</button> \</box> {/ posts feed with images /} {isloading ? ( \<center py={10}> \<spinner size="xl" /> \</center> ) posts length > 0 ? ( \<vstack align="stretch" spacing={4}> {posts map(post => ( \<box key={post id} border="1px solid" bordercolor="gray 600" p={4} borderradius="md" \> \<hstack mb={2}> \<avatar src={post author avatar} name={post author username} size="sm" /> \<text fontweight="bold">{post author username}\</text> \<text fontsize="sm" color="gray 400">• {formatdate(post createdat)}\</text> \</hstack> \<text mb={post image ? 2 4}>{post content}\</text> {/ display post image if available /} {post image && ( \<box mb={4}> \<image src={post image} alt="post image" borderradius="md" maxh="400px" w="auto" /> \</box> )} \<hstack spacing={4}> \<button variant="ghost" size="sm" onclick={() => handlelikepost(post id)} \> ❤️ {post likes} \</button> \<button variant="ghost" size="sm" as={routerlink} to={`/post/${post id}`} \> 💬 comment \</button> \<button variant="ghost" size="sm"> 🔄 share \</button> \</hstack> \</box> ))} \</vstack> ) ( \<text>no posts yet follow users or create your first post!\</text> )} \</box> {/ right sidebar (trending hashtags) /} \<box w={\['0px', '250px']} bg="gray 700" p={4} display={\['none', 'block']} borderleft="1px solid" bordercolor="gray 600" \> \<heading size="md" mb={4}> trending today \</heading> \<simplegrid columns={1} spacing={2}> \<button variant="outline" size="sm" colorscheme="whitealpha">#travel\</button> \<button variant="outline" size="sm" colorscheme="whitealpha">#tech\</button> \<button variant="outline" size="sm" colorscheme="whitealpha">#foodie\</button> \</simplegrid> \</box> \</flex> ); } export default feedpage; this feed component includes several key features authentication check ensures only logged in users can view the feed post creation allows users to create new posts with text and optional images image upload handles image selection, preview, and upload using parse file feed display shows posts from all users in reverse chronological order like functionality allows users to like posts using a simple counter approach navigation provides links to other parts of the application let's examine how back4app is helping us implement these features post creation with parse back4app makes creating posts with images simple // create a new post object const post = parse object extend('post'); const post = new post(); // set post data post set('content', newpostcontent); post set('author', currentuser); post set('likes', 0); // handle image upload if an image is selected if (selectedimage) { const parsefile = new parse file(selectedimage name, selectedimage); await parsefile save(); post set('image', parsefile); } // save the post const savedpost = await post save(); parse file automatically handles file uploads, storage, and url generation, making it easy to add images to posts fetching posts with parse query back4app's query system makes it easy to fetch and display posts // create a query for the post class const query = new parse query('post'); // include the user who created the post query include('author'); // sort by creation date, newest first query descending('createdat'); // limit to 20 posts query limit(20); // execute the query const results = await query find(); the include('author') method is particularly powerful, as it automatically includes the referenced user object with each post, reducing the need for multiple queries back4gram project find here the complete code for a social network sample project built with back4app step 4 – implementing post detail view with comments now, let's create a post detail page that displays a single post with its comments and allows users to add new comments create a file called src/pages/postdetailspage js import react, { usestate, useeffect } from 'react'; import { useparams, usenavigate, link as routerlink } from 'react router dom'; import { box, flex, vstack, heading, text, button, avatar, hstack, textarea, spinner, center, image } from '@chakra ui/react'; import parse from 'parse/dist/parse min js'; import { toaster } from ' /components/ui/toaster'; function postdetailspage() { const { id } = useparams(); const navigate = usenavigate(); const \[post, setpost] = usestate(null); const \[comments, setcomments] = usestate(\[]); const \[newcomment, setnewcomment] = usestate(''); const \[isloading, setisloading] = usestate(true); const \[iscommenting, setiscommenting] = usestate(false); const \[currentuser, setcurrentuser] = usestate(null); // check if user is authenticated useeffect(() => { const checkauth = async () => { try { const user = await parse user current(); if (!user) { navigate('/login'); return; } setcurrentuser(user); } catch (error) { console error('error checking authentication ', error); navigate('/login'); } }; checkauth(); }, \[navigate]); // fetch post and comments useeffect(() => { const fetchpostdetails = async () => { if (!currentuser) return; setisloading(true); try { // get the post const query = new parse query('post'); query include('author'); const postobject = await query get(id); // get comments const commentquery = new parse query('comment'); commentquery equalto('post', postobject); commentquery include('author'); commentquery ascending('createdat'); const commentresults = await commentquery find(); // convert post to plain object const fetchedpost = { id postobject id, content postobject get('content'), author { id postobject get('author') id, username postobject get('author') get('username'), avatar postobject get('author') get('avatar') ? postobject get('author') get('avatar') url() null }, likes postobject get('likes') || 0, createdat postobject get('createdat'), image postobject get('image') ? postobject get('image') url() null }; // convert comments to plain objects const fetchedcomments = commentresults map(comment => ({ id comment id, content comment get('content'), author { id comment get('author') id, username comment get('author') get('username'), avatar comment get('author') get('avatar') ? comment get('author') get('avatar') url() null }, createdat comment get('createdat') })); setpost(fetchedpost); setcomments(fetchedcomments); } catch (error) { console error('error fetching post details ', error); toaster create({ title 'error loading post', description error message, type 'error', }); navigate('/feed'); } finally { setisloading(false); } }; if (id) { fetchpostdetails(); } }, \[id, currentuser, navigate]); // function to add a comment const handleaddcomment = async () => { if (!newcomment trim()) return; setiscommenting(true); try { // get the post object const postquery = new parse query('post'); const postobject = await postquery get(id); // create a new comment object const comment = parse object extend('comment'); const comment = new comment(); // set comment data comment set('content', newcomment); comment set('author', currentuser); comment set('post', postobject); // save the comment await comment save(); // add the new comment to the state const newcommentobj = { id comment id, content comment get('content'), author { id currentuser id, username currentuser get('username'), avatar currentuser get('avatar') ? currentuser get('avatar') url() null }, createdat comment get('createdat') }; setcomments(\[ comments, newcommentobj]); setnewcomment(''); toaster create({ title 'comment added', description 'your comment has been posted successfully!', type 'success', }); } catch (error) { console error('error adding comment ', error); toaster create({ title 'error adding comment', description error message, type 'error', }); } finally { setiscommenting(false); } }; // function to like the post const handlelikepost = async () => { try { // get the post const query = new parse query('post'); const postobject = await query get(id); // increment likes postobject increment('likes'); await postobject save(); // update the post in the state setpost({ post, likes post likes + 1 }); } catch (error) { console error('error liking post ', error); toaster create({ title 'error', description 'could not like the post please try again ', type 'error', }); } }; // format date const formatdate = (date) => { return new date(date) tolocalestring(); }; if (isloading) { return ( \<center h="100vh"> \<spinner size="xl" /> \</center> ); } if (!post) { return ( \<center h="100vh"> \<vstack> \<text>post not found\</text> \<button as={routerlink} to="/feed" colorscheme="blue"> back to feed \</button> \</vstack> \</center> ); } return ( \<box maxw="800px" mx="auto" p={4}> \<button as={routerlink} to="/feed" mb={4} variant="ghost"> ← back to feed \</button> {/ post /} \<box border="1px solid" bordercolor="gray 600" p={6} borderradius="md" mb={6}> \<hstack mb={2}> \<avatar src={post author avatar} name={post author username} size="sm" /> \<vstack align="start" spacing={0}> \<text fontweight="bold">{post author username}\</text> \<text fontsize="sm" color="gray 400">{formatdate(post createdat)}\</text> \</vstack> \</hstack> \<text fontsize="lg" my={post image ? 2 4}>{post content}\</text> {/ display post image if available /} {post image && ( \<box my={4}> \<image src={post image} alt="post image" borderradius="md" maxh="500px" w="auto" /> \</box> )} \<hstack spacing={4}> \<button variant="ghost" onclick={handlelikepost} \> ❤️ {post likes} \</button> \<button variant="ghost"> 🔄 share \</button> \</hstack> \</box> {/ comments section /} \<box> \<heading size="md" mb={4}> comments ({comments length}) \</heading> {/ add comment /} \<box mb={6}> \<textarea placeholder="write a comment " value={newcomment} onchange={(e) => setnewcomment(e target value)} mb={2} /> \<button colorscheme="blue" onclick={handleaddcomment} isloading={iscommenting} disabled={!newcomment trim()} \> post comment \</button> \</box> \<hr style={{ marginbottom "1rem" }} /> {/ comments list /} {comments length > 0 ? ( \<vstack align="stretch" spacing={4}> {comments map(comment => ( \<box key={comment id} p={4} bg="gray 700" borderradius="md"> \<hstack mb={2}> \<avatar src={comment author avatar} name={comment author username} size="sm" /> \<text fontweight="bold">{comment author username}\</text> \<text fontsize="sm" color="gray 400">• {formatdate(comment createdat)}\</text> \</hstack> \<text>{comment content}\</text> \</box> ))} \</vstack> ) ( \<text color="gray 400">no comments yet be the first to comment!\</text> )} \</box> \</box> ); } export default postdetailspage; this post detail page provides several important features 1\ post display shows the complete post with author information, content, image, and likes 2\ comment creation allows users to add new comments to the post 3\ comment listing displays all comments in chronological order 4\ like functionality enables users to like the post let's examine the key aspects of how back4app is helping us implement these features \### fetching post details with related objects back4app makes it easy to fetch a post with related information ```javascript // get the post const query = new parse query('post'); query include('author'); const postobject = await query get(id); the include('author') method automatically retrieves the related user object along with the post, eliminating the need for separate queries querying related comments back4app's query system allows us to find all comments related to a specific post // get comments const commentquery = new parse query('comment'); commentquery equalto('post', postobject); commentquery include('author'); commentquery ascending('createdat'); const commentresults = await commentquery find(); the equalto('post', postobject) method filters comments to only those related to the current post creating comments with pointers creating a comment with a relationship to a post is straightforward // create a new comment object const comment = parse object extend('comment'); const comment = new comment(); // set comment data comment set('content', newcomment); comment set('author', currentuser); comment set('post', postobject); // save the comment await comment save(); the post field is set as a pointer to the post object, establishing the relationship between the comment and the post back4gram project find here the complete code for a social network sample project built with back4app step 5 – implementing advanced like functionality with parse the simple like counter we've implemented so far works well for basic functionality, but it has limitations users can like a post multiple times a user can't "unlike" a post we can't show who liked a post let's create a more advanced like system using a separate like class to track individual likes setting up the like class first, create a new class in your back4app dashboard click "create a class" in the database browser enter "like" as the class name and select "custom" as the type add the following columns user (type pointer, target class user) post (type pointer, target class post) implementing like management in our code now, let's update our post liking functionality in the postdetailspage js file // add this state at the beginning of the component const \[hasliked, sethasliked] = usestate(false); // add this to the useeffect that fetches post details // check if current user has liked this post const likequery = new parse query('like'); likequery equalto('user', currentuser); likequery equalto('post', postobject); const userlike = await likequery first(); sethasliked(!!userlike); // replace the handlelikepost function with this new version const handlelikepost = async () => { try { // get the post const query = new parse query('post'); const postobject = await query get(id); // check if user has already liked the post const likequery = new parse query('like'); likequery equalto('user', currentuser); likequery equalto('post', postobject); const existinglike = await likequery first(); if (existinglike) { // user already liked the post, so remove the like await existinglike destroy(); // decrement likes count on the post postobject increment('likes', 1); await postobject save(); // update ui sethasliked(false); setpost({ post, likes post likes 1 }); } else { // user hasn't liked the post yet, so add a like const like = parse object extend('like'); const like = new like(); like set('user', currentuser); like set('post', postobject); await like save(); // increment likes count on the post postobject increment('likes'); await postobject save(); // update ui sethasliked(true); setpost({ post, likes post likes + 1 }); } } catch (error) { console error('error toggling like ', error); toaster create({ title 'error', description 'could not process your like please try again ', type 'error', }); } }; then, update the like button to reflect the current state \<button variant="ghost" onclick={handlelikepost} color={hasliked ? "red 500" "inherit"} \> {hasliked ? "❤️" "🤍"} {post likes} \</button> this implementation tracks individual likes using a separate like class allows users to toggle likes (like and unlike) visually indicates whether the current user has liked the post maintains the like count on the post for efficient querying showing who liked a post you can also add functionality to show who has liked a post // add this state const \[likeusers, setlikeusers] = usestate(\[]); const \[showlikes, setshowlikes] = usestate(false); // add this function const fetchlikes = async () => { try { const postquery = new parse query('post'); const postobject = await postquery get(id); const likequery = new parse query('like'); likequery equalto('post', postobject); likequery include('user'); const likes = await likequery find(); const users = likes map(like => { const user = like get('user'); return { id user id, username user get('username'), avatar user get('avatar') ? user get('avatar') url() null }; }); setlikeusers(users); setshowlikes(true); } catch (error) { console error('error fetching likes ', error); } }; then add a ui element to display the users who liked the post \<text color="blue 400" cursor="pointer" onclick={fetchlikes} fontsize="sm" \> see who liked this post \</text> {showlikes && ( \<box mt={2} p={2} bg="gray 700" borderradius="md"> \<heading size="xs" mb={2}>liked by \</heading> {likeusers length > 0 ? ( \<vstack align="stretch"> {likeusers map(user => ( \<hstack key={user id}> \<avatar size="xs" src={user avatar} name={user username} /> \<text fontsize="sm">{user username}\</text> \</hstack> ))} \</vstack> ) ( \<text fontsize="sm">no likes yet\</text> )} \</box> )} back4gram project find here the complete code for a social network sample project built with back4app step 6 – implementing real time updates with parse live query one of the most powerful features of back4app is the ability to receive real time updates with live query this allows your application to automatically update when new posts or comments are created without the need for manual refreshing setting up live query on back4app first, you need to enable live query for your application in back4app go to your back4app dashboard navigate to app settings > server settings scroll down to "parse live query class names" add "post" and "comment" to the list of classes save your changes implementing live query for real time posts let's update our feedpage js to include live query for real time post updates // add to your import statements import { useeffect, useref } from 'react'; // add to your component const livequerysubscription = useref(null); // add this to your component to set up and clean up the subscription useeffect(() => { const setuplivequery = async () => { if (!currentuser) return; try { console log('setting up live query for posts'); // create a query that will be used for the subscription const query = new parse query('post'); // subscribe to the query livequerysubscription current = await query subscribe(); console log('successfully subscribed to live query'); // handle connection open livequerysubscription current on('open', () => { console log('live query connection opened'); }); // handle new posts livequerysubscription current on('create', (post) => { console log('new post received via live query ', post id); // skip posts from the current user as they're already in the ui if (post get('author') id === currentuser id) { console log('skipping post from current user'); return; } // format the new post const author = post get('author'); const newpost = { id post id, content post get('content'), author { id author id, username author get('username'), avatar author get('avatar') ? author get('avatar') url() null }, image post get('image') ? post get('image') url() null, likes post get('likes') || 0, createdat post get('createdat') }; // add the new post to the posts state setposts(prevposts => \[newpost, prevposts]); }); // handle post updates livequerysubscription current on('update', (post) => { console log('post updated via live query ', post id); // format the updated post const newlikes = post get('likes') || 0; // update the post in the state setposts(prevposts => prevposts map(p => p id === post id ? { p, likes newlikes } p ) ); }); // handle errors livequerysubscription current on('error', (error) => { console error('live query error ', error); }); } catch (error) { console error('error setting up live query ', error); } }; setuplivequery(); // clean up subscription return () => { if (livequerysubscription current) { console log('unsubscribing from live query'); livequerysubscription current unsubscribe(); } }; }, \[currentuser]); implementing live query for real time comments similarly, let's update our postdetailspage js to include live query for real time comments // add to your import statements import { useeffect, useref } from 'react'; // add to your component const livequerysubscription = useref(null); // add this to your component to set up and clean up the subscription useeffect(() => { const setuplivequery = async () => { if (!currentuser || !id) return; try { console log('setting up live query for comments'); // get the post object to use in the query const postquery = new parse query('post'); const postobject = await postquery get(id); // create a query that will be used for the subscription const query = new parse query('comment'); query equalto('post', postobject); // subscribe to the query livequerysubscription current = await query subscribe(); console log('successfully subscribed to live query for comments'); // handle connection open livequerysubscription current on('open', () => { console log('live query connection opened'); }); // handle new comments livequerysubscription current on('create', (comment) => { console log('new comment received via live query ', comment id); // skip comments from the current user as they're already in the ui if (comment get('author') id === currentuser id) { console log('skipping comment from current user'); return; } // format the new comment const author = comment get('author'); const newcomment = { id comment id, content comment get('content'), author { id author id, username author get('username'), avatar author get('avatar') ? author get('avatar') url() null }, createdat comment get('createdat') }; // add the new comment to the comments state setcomments(prevcomments => \[ prevcomments, newcomment]); }); // handle errors livequerysubscription current on('error', (error) => { console error('live query error ', error); }); } catch (error) { console error('error setting up live query for comments ', error); } }; setuplivequery(); // clean up subscription return () => { if (livequerysubscription current) { console log('unsubscribing from live query'); livequerysubscription current unsubscribe(); } }; }, \[currentuser, id]); with these live query implementations, your social network will now update in real time new posts from other users will appear automatically in the feed like counts will update in real time when other users like a post new comments will appear automatically on the post detail page back4gram project find here the complete code for a social network sample project built with back4app step 7 – advanced queries and performance optimization as your social network grows, performance becomes increasingly important let's explore some advanced techniques to optimize your application using back4app's powerful query capabilities implementing pagination instead of loading all posts at once, implement pagination to load them in batches // add these state variables const \[page, setpage] = usestate(0); const \[hasmoreposts, sethasmoreposts] = usestate(true); const postsperpage = 10; // update your fetchposts function const fetchposts = async (loadmore = false) => { if (!currentuser) return; if (!loadmore) { setisloading(true); } try { const query = new parse query('post'); query include('author'); query descending('createdat'); query limit(postsperpage); query skip(page postsperpage); const results = await query find(); // process and format posts as before const fetchedposts = \[ ]; // update the hasmoreposts state sethasmoreposts(results length === postsperpage); // update the posts state if (loadmore) { setposts(prevposts => \[ prevposts, fetchedposts]); } else { setposts(fetchedposts); } // update the page if this was a "load more" request if (loadmore) { setpage(prevpage => prevpage + 1); } } catch (error) { // handle errors } finally { setisloading(false); } }; // add a load more button at the bottom of your posts list {hasmoreposts && ( \<button onclick={() => fetchposts(true)} variant="outline" isloading={isloading} mt={4} \> load more posts \</button> )} implementing a user specific feed for a more personalized experience, you might want to show posts only from users that the current user follows // assuming you have a "follow" class with "follower" and "following" pointers const fetchfollowingposts = async () => { try { // first, find all users that the current user follows const followquery = new parse query('follow'); followquery equalto('follower', currentuser); const followings = await followquery find(); // extract the users being followed const followedusers = followings map(follow => follow\ get('following')); // add the current user to show their posts too followedusers push(currentuser); // create a query for posts from these users const query = new parse query('post'); query containedin('author', followedusers); query include('author'); query descending('createdat'); query limit(20); const results = await query find(); // process results } catch (error) { // handle errors } }; using cloud functions for complex operations for complex operations that would require multiple queries, consider using back4app cloud functions go to your back4app dashboard navigate to cloud code > cloud functions create a new function // example function to get a feed with posts, likes, and comment counts parse cloud define("getfeed", async (request) => { try { const user = request user; const page = request params page || 0; const limit = request params limit || 10; if (!user) { throw new error("user must be logged in"); } // query for posts const query = new parse query("post"); query include("author"); query descending("createdat"); query limit(limit); query skip(page limit); const posts = await query find({ usemasterkey true }); // format posts and get additional info const formattedposts = await promise all(posts map(async (post) => { // check if user has liked this post const likequery = new parse query("like"); likequery equalto("post", post); likequery equalto("user", user); const hasliked = await likequery count({ usemasterkey true }) > 0; // get comment count const commentquery = new parse query("comment"); commentquery equalto("post", post); const commentcount = await commentquery count({ usemasterkey true }); // format post for response return { id post id, content post get("content"), image post get("image") ? post get("image") url() null, author { id post get("author") id, username post get("author") get("username"), avatar post get("author") get("avatar") ? post get("author") get("avatar") url() null }, likes post get("likes") || 0, hasliked hasliked, commentcount commentcount, createdat post get("createdat") }; })); return { posts formattedposts }; } catch (error) { throw new error(`error fetching feed ${error message}`); } }); then call this cloud function from your app const fetchfeed = async () => { try { setisloading(true); const result = await parse cloud run('getfeed', { page 0, limit 10 }); setposts(result posts); } catch (error) { console error('error fetching feed ', error); toaster create({ title 'error loading feed', description error message, type 'error', }); } finally { setisloading(false); } }; this approach can significantly reduce the number of queries to the database and improve performance back4gram project find here the complete code for a social network sample project built with back4app conclusion in this tutorial, you've built a comprehensive social network feed with interactive features using back4app let's recap what you've accomplished data model design created a structured data model for posts, comments, and likes feed implementation built a feed page that displays posts from all users post creation implemented functionality for users to create posts with text and images comment system created a comment system that allows users to engage with posts like functionality implemented both simple and advanced like systems real time updates added live query for real time post and comment updates performance optimization explored techniques to improve performance as your app scales back4app has provided a secure and scalable database for storing user generated content file storage for post images built in user authentication for security live query for real time updates cloud functions for complex backend operations with these building blocks in place, your social network has a solid foundation that can scale as your user base grows next steps to further enhance your social network, consider implementing these features notifications alert users when their posts receive likes or comments user following system allow users to follow each other and customize their feeds hashtags and search implement a hashtag system and enhanced search functionality media rich posts support videos, multiple images, and other media types analytics track engagement and user behavior to improve your application for the complete code of the back4gram social network application, you can check out the github repository https //github com/templates back4app/back4gram by leveraging back4app's powerful backend services, you can focus on creating a great user experience while the platform handles the complex infrastructure needed for a social networking application