好友与群组排行榜 #

Nakama排行榜为玩家提供了可以参与的竞争性活动。随着游戏的发展，大规模的排行榜可能会让人感觉静止不变，而且玩家也很难提升排名。您可以通过以下方式解决此问题：

使用排行榜列表API，您可以传入用户ID列表以创建自定义排行榜视图。

以下代码示例向您展示了如何获取群组成员或用户好友的排行榜记录。

创建排行榜 #

在服务器上创建一个每周一00:00重置的排行榜。

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func InitModule(ctx context.Context, logger runtime.Logger, db *sql.DB, nk runtime.NakamaModule, initializer runtime.Initializer) error {
  // Create a weekly leaderboard
  id := "weekly_leaderboard"
  authoritative := false
  sortOrder := "desc"
  operator := "incr"
  resetSchedule := "0 0 * * 1"
  metadata := make(map[string]interface{})

  if err := nk.LeaderboardCreate(ctx, id, authoritative, sortOrder, operator, resetSchedule, metadata); err != nil {
    logger.Error("error creating leaderboard")
    return err
  }
}
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let InitModule: nkruntime.InitModule = function (ctx: nkruntime.Context, logger: nkruntime.Logger, nk: nkruntime.Nakama, initializer: nkruntime.Initializer) {
  const id = 'weekly_leaderboard';
  const authoritative = false;
  const sortOrder = nkruntime.SortOrder.DESCENDING;
  const operator = nkruntime.Operator.INCREMENTAL;
  const resetSchedule = '0 0 * * 1';
  const metadata = {};

  nk.leaderboardCreate(id, authoritative, sortOrder, operator, resetSchedule, metadata);
}
Code snippet for this language Lua has not been found. Please choose another language to show equivalent examples.

获取排行榜的自定义视图 #

定义RPC的有效负载结构：

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type leaderboardRecord struct {
  Username string `json:"username"`
  UserId   string `json:"userId"`
  Score    int    `json:"score"`
  Rank     int    `json:"rank"`
}
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interface LeaderboardRecord {
  username: string,
  userId: string,
  score: number,
  rank: number
}
Code snippet for this language Lua has not been found. Please choose another language to show equivalent examples.

创建一个辅助函数，该函数将获取用户ID阵列并返回这些记录的阵列以及基于用户分数的相对排名值。

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func getLeaderboardForUsers(leaderboardId string, userIds []string, ctx context.Context, logger runtime.Logger, nk runtime.NakamaModule) ([]leaderboardRecord, error) {
  // Get all leaderboard records for user Ids
  _, records, _, _, err := nk.LeaderboardRecordsList(ctx, leaderboardId, userIds, 0, "", 0)
  if err != nil {
    return nil, err
  }

  // Create result slice and add a rank value
  results := []leaderboardRecord{}
  for i, record := range records {
    r := leaderboardRecord{
      Username: record.Username.Value,
      UserId:   record.OwnerId,
      Score:    int(record.Score),
      Rank:     len(records) - i,
    }
    results = append(results, r)
  }

  return results, nil
}
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const getLeaderboardForUsers = function (leaderboardId: string, userIds: string[], logger: nkruntime.Logger, nk: nkruntime.Nakama): LeaderboardRecord[] {
  const recordsList = nk.leaderboardRecordsList(leaderboardId, userIds);
  const results: LeaderboardRecord[] = [];

  recordsList.records.forEach(function (leaderboardRecord, i) {
    results.push({
      username: leaderboardRecord.username,
      userId: leaderboardRecord.ownerId,
      score: leaderboardRecord.score,
      rank: recordsList.records.length - i
    });
  });

  return results;
}
Code snippet for this language Lua has not been found. Please choose another language to show equivalent examples.

获取群组排行榜视图 #

现在您有了获取用户列表排行榜的通用函数，接下来需要创建一个函数来获取群组的排行榜。

为RPC定义负载结构：

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type groupLeaderboardRecordsPayload struct {
  GroupId       string `json:"groupId"`
  LeaderboardId string `json:"leaderboardId"`
}
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interface groupLeaderboardRecordsPayload {
  groupId: string,
  leaderboardId: string
}
Code snippet for this language Lua has not been found. Please choose another language to show equivalent examples.

创建一个函数，该函数将从群组中获取成员切片，然后获取其排行榜：

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func getGroupLeaderboardRecords(ctx context.Context, logger runtime.Logger, db *sql.DB, nk runtime.NakamaModule, payload string) (string, error) {
  // Unmarshal the payload
  data := &groupLeaderboardRecordsPayload{}
  if err := json.Unmarshal([]byte(payload), data); err != nil {
    logger.Error("error unmarshaling payload")
    return "", err
  }

  // Get leaderboard
  leaderboards, err := nk.LeaderboardsGetId(ctx, []string{data.LeaderboardId})
  if err != nil {
    logger.Error("error getting leaderboards")
    return "", err
  }

  if len(leaderboards) == 0 {
    errorMessage := fmt.Sprintf("error finding leaderboard: %s", data.LeaderboardId)
    logger.Error(errorMessage)
    return "", errors.New(errorMessage)
  }

  // Get group members
  members, _, err := nk.GroupUsersList(ctx, data.GroupId, 100, nil, "")
  if err != nil {
    logger.Error("error getting group members")
    return "", err
  }

  // Get a slice of memberIds
  memberIds := []string{}
  for _, member := range members {
    memberIds = append(memberIds, member.User.Id)
  }

  // Get all leaderboard records for users
  results, err := getLeaderboardForUsers(leaderboards[0].Id, memberIds, ctx, logger, nk)
  if err != nil {
    logger.Error("error getting leaderboard records")
    return "", err
  }

  // Return the leaderboard records to the user
  bytes, err := json.Marshal(results)
  if err != nil {
    logger.Error("error marshaling result")
    return "", err
  }

  return string(bytes), nil
}
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const getGroupLeaderboardRecords: nkruntime.RpcFunction = function (ctx: nkruntime.Context, logger: nkruntime.Logger, nk: nkruntime.Nakama, payload: string): string | void {
  // Parse the payload
  const data = <groupLeaderboardRecordsPayload> JSON.parse(payload);
  
  if (!data) {
    throw new Error('Error parsing payload');
  }
  
  // Get leaderboard
  const leaderboards = nk.leaderboardsGetId([data.leaderboardId]);
  
  if (leaderboards.length == 0) {
    throw new Error(`Error finding leaderboard: ${data.leaderboardId}`);
  }
  
  // Get group members
  const members = nk.groupUsersList(data.groupId, 100);
  
  // Get a slice of memberIds
  const memberIds: string[] = [];
  members.groupUsers.forEach(function (groupUser) {
    memberIds.push(groupUser.user.userId);
  });
  
  // Get all leaderboard records for users
  const results = getLeaderboardForUsers(leaderboards[0].id, memberIds, logger, nk);
  
  // Return the leaderboard records to the user
  return JSON.stringify(results);
};
Code snippet for this language Lua has not been found. Please choose another language to show equivalent examples.

注册该函数并将其公开为可以从客户端调用的远程过程：

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func InitModule(ctx context.Context, logger runtime.Logger, db *sql.DB, nk runtime.NakamaModule, initializer runtime.Initializer) error {
  // ...

  // Register RPC to retrieve a custom view over a leaderboard based on group members
  if err := initializer.RegisterRpc("getGroupLeaderboardRecords", getGroupLeaderboardRecords); err != nil {
    logger.Error(`error registering "getGroupLeaderboardRecords" rpc`)
    return err
  }

  return nil
}
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let InitModule: nkruntime.InitModule = function (ctx: nkruntime.Context, logger: nkruntime.Logger, nk: nkruntime.Nakama, initializer: nkruntime.Initializer) {
  // ... 

  // Register RPC to retrieve a custom view over a leaderboard based on group members
  initializer.registerRpc('getGroupLeaderboardRecords', getGroupLeaderboardRecords);
}
Code snippet for this language Lua has not been found. Please choose another language to show equivalent examples.

获取好友排行榜视图 #

同样，创建一个函数来获取用户好友的排行榜。

为RPC定义负载结构：

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type friendsLeaderboardRecordsPayload struct {
  LeaderboardId string `json:"leaderboardId"`
}
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interface friendsLeaderboardReocrdsPayload {
  leaderboardId: string
}
Code snippet for this language Lua has not been found. Please choose another language to show equivalent examples.

创建一个函数，该函数将获取用户好友切片，然后获取他们的排行榜：

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func getFriendLeaderboardRecords(ctx context.Context, logger runtime.Logger, db *sql.DB, nk runtime.NakamaModule, payload string) (string, error) {
  // Unmarshal the payload
  data := &friendsLeaderboardRecordsPayload{}
  if err := json.Unmarshal([]byte(payload), data); err != nil {
    logger.Error("error unmarshaling payload")
    return "", err
  }

  // Get leaderboard
  leaderboards, err := nk.LeaderboardsGetId(ctx, []string{data.LeaderboardId})
  if err != nil {
    logger.Error("error getting leaderboards")
    return "", err
  }

  if len(leaderboards) == 0 {
    errorMessage := fmt.Sprintf("error finding leaderboard: %s", data.LeaderboardId)
    logger.Error(errorMessage)
    return "", errors.New(errorMessage)
  }

  // Get user id from context
  userId, ok := ctx.Value(runtime.RUNTIME_CTX_USER_ID).(string)
  if !ok {
    errorMessage := fmt.Sprintf("error getting user id from context")
    logger.Error(errorMessage)
    return "", errors.New(errorMessage)
  }

  // Get friends (where state is 0 - mutual friends)
  state := 0
  friends, _, err := nk.FriendsList(ctx, userId, 100, &state, "")
  if err != nil {
    logger.Error("error getting friends")
    return "", err
  }

  // Get a slice of memberIds
  friendIds := []string{}
  for _, member := range friends {
    friendIds = append(friendIds, member.User.Id)
  }

  // Get all leaderboard records for users
  results, err := getLeaderboardForUsers(leaderboards[0].Id, friendIds, ctx, logger, nk)
  if err != nil {
    logger.Error("error getting leaderboard records")
    return "", err
  }

  // Return the leaderboard records to the user
  bytes, err := json.Marshal(results)
  if err != nil {
    logger.Error("error marshaling result")
    return "", err
  }

  return string(bytes), nil
}
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const getFriendLeaderboardRecords: nkruntime.RpcFunction = function (ctx: nkruntime.Context, logger: nkruntime.Logger, nk: nkruntime.Nakama, payload: string): string | void {
  // Parse the payload
  const data = <friendsLeaderboardReocrdsPayload> JSON.parse(payload);

  if (!data) {
    throw new Error('Error parsing payload');
  }

  // Get leaderboard
  const leaderboards = nk.leaderboardsGetId([data.leaderboardId]);

  if (leaderboards.length == 0) {
    throw new Error(`Error finding leaderboard: ${data.leaderboardId}`);
  }

  // Get friends (where state is 0 - mutual friends)
  const friendsList = nk.friendsList(ctx.userId, 100, 0);

  // Get a slice of friendIds
  const friendIds: string[] = [];
  friendsList.friends.forEach(function (friend) {
    friendIds.push(friend.user.userId);
  });

  // Get all leaderboard records for users
  const results = getLeaderboardForUsers(leaderboards[0].id, friendIds, logger, nk);

  // Return the leaderboard records to the user
  return JSON.stringify(results);
};
Code snippet for this language Lua has not been found. Please choose another language to show equivalent examples.

注册该函数并将其公开为可以从客户端调用的远程过程：

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func InitModule(ctx context.Context, logger runtime.Logger, db *sql.DB, nk runtime.NakamaModule, initializer runtime.Initializer) error {
  // ...

  // Register RPC to retrieve a custom view over a leaderboard based on friends
  if err := initializer.RegisterRpc("getFriendLeaderboardRecords", getFriendLeaderboardRecords); err != nil {
    logger.Error(`error registering "getFriendLeaderboardRecords" rpc`)
    return err
  }

  return nil
}
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let InitModule: nkruntime.InitModule = function (ctx: nkruntime.Context, logger: nkruntime.Logger, nk: nkruntime.Nakama, initializer: nkruntime.Initializer) {
  // ...

  // Register RPC to retrieve a custom view over a leaderboard based on friends
  initializer.registerRpc('getFriendLeaderboardRecords', getFriendLeaderboardRecords);
}
Code snippet for this language Lua has not been found. Please choose another language to show equivalent examples.