javascript - 将多个结果插入到express.js路由中的req对象中

Question

我正在使用 ElasticSearch 运行 Express.js/Node.js 应用程序。我正在尝试查看同一索引中多种类型的结果。我在这里所做的是运行搜索查询，并根据查询结果执行第二个搜索查询。我还可以通过观察 node.js 控制台看到 elasticsearch 为玩家返回结果。但它们没有插入到我的结果对象/数组中。我正在使用快速中间件，因为我必须执行两个搜索并将结果显示为一个。

routes/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);

我通过阅读post1想出了这个解决方案和 post2 。我可以显示团队数组。但玩家数组中却没有任何结果。我在这里做错了什么。

Answer 1

在您的 searchPlayer 函数中，next() 调用应放置在 searchPlayers() 调用的回调中，基本上与您的操作完全相同为searchTeam()函数做了。

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);

正如 Talha Awan 所建议的，您最好不要在中间件中执行此操作，而应使用专用库，例如​​ async one (但还有很多其他的)

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);