在express.js路由中向req對象插入多個結果

Question

我正在使用ElasticSearch運行Express.js / Node.js應用程序。 我試圖查看同一索引中多種類型的結果。 我在這里執行的是運行搜索查詢，並根據查詢結果執行第二個搜索查詢。 通過觀察node.js控制台，我還可以看到elasticsearch為玩家返回了結果。 但是它們沒有插入到我的結果對象/數組中。 我使用快速中間件，因為我必須執行兩個搜索並將結果顯示為一個。

路線/index.js

function searchTeam(req, res, next){
  searchModuleTeams.searchTeams(req.body, function(data) {
    req.teams = data;
    next();
  });
}

function searchPlayer(req, res, next){
  //req.players = [];
  req.teams.forEach(function(team){
    req.body = {searchTerm:team._source.shortName};
    searchModulePlayers.searchPlayers(req.body, function(data){
      req.players.push(data);
      console.log(req.players);
    });
  });
  next();
}

function renderResults(req, res){
  res.render('index',{
    title:'Search Teams and Players',
    teams:req.teams,
    players:req.players
  });
}

router.post('/search-tp',searchTeam, searchPlayer, renderResults);

我通過閱讀post1和post2提出了這個解決方案。 我可以顯示teams數組。 但是什么都不來自玩家數組。 我在這里做錯了什么。

Answer 1

在searchPlayer函數中， next()調用應放置在searchPlayers()調用的回調內，基本上與您對searchTeam()函數所做的完全一樣。

function searchTeam(req, res, next){
  searchModuleTeams.searchTeams(req.body, function(data) {
    req.teams = data;
    next();
  });
}

function searchPlayer(req, res, next){
  req.players = [];                      <--- uncomment this...
  req.teams.forEach(function(team){
    req.body = {searchTerm:team._source.shortName};
    searchModulePlayers.searchPlayers(req.body, function(data){
      req.players.push(data);            <--- ...otherwise this will fail
      next();                            <--- move next() here
    });
  });
}

function renderResults(req, res){
  res.render('index',{
    title:'Search Teams and Players',
    teams:req.teams,
    players:req.players
  });
}

router.post('/search-tp',searchTeam, searchPlayer, renderResults);

而且正如Talha Awan所建議的那樣，您最好不要在中間件中執行此操作，而應使用專用庫，例如async庫（但還有很多其他庫）

import waterfall from 'async/waterfall';

function searchTeam(callback){
  searchModuleTeams.searchTeams(req.body, function(teams) {
    callback(null, teams);
  });
}

function searchPlayer(teams, callback){
  let teamPlayers = [];
  async.each(teams, function(team, teamCallback) {
    let search = {searchTerm: team._source.shortName};
    searchModulePlayers.searchPlayers(search, function(players){
       teamPlayers.push(players);
       teamCallback();
    });
  }, function(err) {
    callback(err, teams, teamPlayers);
  });
}

function renderResults(req, res){
  async.waterfall([
    searchTeam,
    searchPlayer
  ], function (err, teams, players) {
    res.render('index',{
      title:'Search Teams and Players',
      teams: teams,
      players: players
    });
  });
}

router.post('/search-tp', renderResults);