How to Set Up a Fantasy Sports League Platform in FlutterFlow

Create a `leagues` collection with fields: name (String), sport (String: football/basketball/baseball), maxTeams (Integer), draftDate (Timestamp), ownerId (String), memberIds (List of Strings), status (String: drafting/active/completed). Add a `teams` subcollection under each league with fields: userId (String), teamName (String), roster (List of Maps with playerId and position), totalPoints (Double). Create a top-level `players` collection with fields: name (String), realTeam (String), position (String), stats (Map with sport-specific fields like touchdowns, yards, rebounds), fantasyPoints (Double), isDrafted (Boolean), leagueId (String). Register all collections in FlutterFlow's Data panel.

Create a Leagues page with a ListView showing leagues the current user belongs to (filtered by arrayContains on memberIds). Add a FloatingActionButton to create a new league: a BottomSheet form with TextFields for league name, a DropDown for sport type, a number input for max teams, and a DateTimePicker for draft date. On create, add the current user to memberIds and set them as ownerId. For joining, add a Join League page where users enter a league invite code (use the Firestore document ID as the code). On join, add the user's UID to the league's memberIds array and create a team document in the teams subcollection with a default team name and empty roster.

Create a DraftBoard page that receives leagueId as a parameter. At the top, show a Text displaying whose turn it is (calculated by round-robin order of memberIds). Below, add a ListView of available players — query the players collection where isDrafted == false for this league, filterable by position ChoiceChips (QB/RB/WR/TE/K for football). Each player card shows name, team, position, and projected points. Add a Draft Player button on each card. On tap, call a Cloud Function that uses a Firestore transaction: read the player document → verify isDrafted is still false → set isDrafted to true and leagueId → add the player to the drafting user's roster array on their team document → advance the draft turn. The transaction prevents two users from drafting the same player simultaneously.

1// Cloud Function: Draft a player with transaction
2exports.draftPlayer = functions.https.onCall(async (data, context) => {
3  const { leagueId, playerId, position } = data;
4  const uid = context.auth.uid;
5  const db = admin.firestore();
6
7  return db.runTransaction(async (txn) => {
8    const playerRef = db.collection('players').doc(playerId);
9    const playerDoc = await txn.get(playerRef);
10    const player = playerDoc.data();
11
12    if (player.isDrafted && player.leagueId === leagueId) {
13      throw new functions.https.HttpsError(
14        'already-exists', 'Player already drafted');
15    }
16
17    // Mark player as drafted
18    txn.update(playerRef, {
19      isDrafted: true,
20      leagueId: leagueId,
21    });
22
23    // Add to user's roster
24    const teamQuery = await db
25      .collection(`leagues/${leagueId}/teams`)
26      .where('userId', '==', uid).limit(1).get();
27    const teamRef = teamQuery.docs[0].ref;
28
29    txn.update(teamRef, {
30      roster: admin.firestore.FieldValue.arrayUnion({
31        playerId, position, name: player.name,
32      }),
33    });
34
35    return { success: true, player: player.name };
36  });
37});

Create a MyTeam page showing the current user's roster. Add a ListView bound to the team document's roster array. Each item shows the player name, position, real team, and current fantasy points (joined from the players collection). Show a total points Text at the top summing all roster players' fantasy points. For the league leaderboard, create a Standings tab on the league page with a ListView bound to the teams subcollection ordered by totalPoints descending. Each row shows: rank number, team name, owner name, and total points. Highlight the top 3 with gold, silver, and bronze Container styling. Add the current user's team with a 'You' badge for quick identification.

Create a Cloud Function that runs on a schedule (e.g., daily after games) or can be triggered manually by the league admin. The function fetches real-game statistics from your sports data API (or reads from a manually updated stats collection), calculates fantasy points per player using your scoring rules (e.g., 6 points per touchdown, 1 point per 10 yards), updates each player's fantasyPoints field, then recalculates totalPoints for every team in every active league by summing their roster players' fantasy points. Update the team documents with the new totals. This keeps the leaderboard current without any manual intervention.

Create a `trades` subcollection under each league with fields: proposerTeamId (String), receiverTeamId (String), offeredPlayerIds (List), requestedPlayerIds (List), status (String: pending/accepted/rejected), timestamp (Timestamp). On the roster page, add a Trade button that opens a TradeProposal page. The user selects players from their roster to offer and players from the opponent's roster to request. On submit, create a trade document with status 'pending'. The receiving team sees the proposal in a Trades Inbox ListView. On accept, a Cloud Function atomically swaps the players between rosters using a batch write. On reject, update the status. Add a trade deadline field on the league document after which trades are disabled.