How to Build a Social Media Feed with Custom Content Filters in FlutterFlow

Ensure your posts collection has these fields: content (String), imageUrl (String, optional), videoUrl (String, optional), type (String: photo/video/text), authorId (String), likeCount (Integer), commentCount (Integer), timestamp (Timestamp), trendingScore (Double, updated by Cloud Function). On the users collection, ensure you have a followingIds array (List of Strings) containing UIDs of followed users, and a blockedIds array for blocked users. Create composite Firestore indexes for the query combinations you will use: type + timestamp, type + trendingScore, type + likeCount. Register the collections in FlutterFlow.

At the top of your FeedPage, add a Column containing three filter widgets. First, a ChoiceChips widget with options: All, Photos, Videos, Text. Bind the selected value to a Page State variable called contentTypeFilter (String, default 'All'). Second, a Row with a Text 'Following Only' and a Switch. Bind the Switch to a Page State boolean followingOnly (default false). Third, a DropDown with options: Recent, Popular, Trending. Bind to a Page State variable sortBy (String, default 'Recent'). Style the filter bar in a horizontal Row or Wrap so it scrolls horizontally on small screens. Each filter change should trigger a re-query of the feed ListView below.

Below the filter bar, add a ListView bound to a Backend Query on the posts collection. Build the query dynamically based on Page State: (1) If contentTypeFilter is not 'All', add a where clause: type == selectedType. (2) If followingOnly is true, add a where clause: authorId whereIn currentUser.followingIds (note: Firestore whereIn is limited to 10 values, so if the user follows more than 10 people, batch into groups of 10 and merge results). (3) For sortBy: 'Recent' orders by timestamp descending, 'Popular' orders by likeCount descending, 'Trending' orders by trendingScore descending. Since FlutterFlow's visual query builder may not support fully dynamic queries, use a Custom Function or multiple conditional Backend Queries that switch based on the active filter combination.

Create a scheduled Cloud Function that runs every hour (or on demand). For each post created within the last 7 days, calculate a trending score using a time-decay formula: trendingScore = (likeCount * 2 + commentCount * 3) / hoursAge^1.5. This gives recent posts with high engagement a boost, while older posts decay regardless of total engagement. Update the trendingScore field on each post document. Posts older than 7 days get a trendingScore of 0. This allows the Trending sort option to show posts that are gaining momentum right now, not just all-time popular posts.

1// Cloud Function: Calculate trending scores
2const functions = require('firebase-functions');
3const admin = require('firebase-admin');
4admin.initializeApp();
5
6exports.calculateTrending = functions.pubsub
7  .schedule('every 1 hours').onRun(async () => {
8    const db = admin.firestore();
9    const weekAgo = new Date(Date.now() - 7 * 24 * 60 * 60 * 1000);
10    const posts = await db.collection('posts')
11      .where('timestamp', '>=', admin.firestore.Timestamp.fromDate(weekAgo))
12      .get();
13
14    const batch = db.batch();
15    posts.docs.forEach(doc => {
16      const data = doc.data();
17      const hoursAge = Math.max(1,
18        (Date.now() - data.timestamp.toMillis()) / 3600000);
19      const score = (data.likeCount * 2 + data.commentCount * 3)
20        / Math.pow(hoursAge, 1.5);
21      batch.update(doc.ref, { trendingScore: score });
22    });
23    await batch.commit();
24  });

Firestore's whereNotIn operator is limited to 10 values, which is insufficient for users who have blocked many accounts. Instead, handle blocking client-side. After the feed query returns results, apply a filter in a Custom Function that removes posts where the authorId appears in the current user's blockedIds array. In FlutterFlow, bind the ListView to the filtered result rather than the raw query. For the block action itself, add a 'Block User' option in a post's three-dot menu. On tap, add the author's UID to the current user's blockedIds array using arrayUnion, then refresh the feed to remove their content immediately.