Mongoose / JavaScript - 保存错误 - 未定义的对象

Question

我正在尝试在 2 teams 之间保存 match，我正在通过下拉列表传递 2 teams。

当我在Team.findByKey 方法内使用util.log 将homeTeam 输出到控制台时，它成功运行，输出如下：

3 Mar 19:52:33 - { name: 'Liverpool',
  _id: 51312074bb176ba624000007,
  __v: 0,
  key: 1362174068837 }

但是当我尝试在此方法之外执行此操作时，我会得到以下输出，这意味着当我尝试将其保存为比赛时，主队显示为 undefined 而不是 @987654329 的 id @：

3 Mar 19:54:09 - [object Object]

我的问题是，我最终希望在一次扑救中将主队和客队都救到同一场比赛中。保存匹配的代码在 Team.findByKey 方法中有效，如下所示：

  app.get('/save/matchTest', function(req, res) {
    var key = 1362174006191; // Man Utd 51312036bb176ba624000001
    Team.findByKey(key, function(err, team) {
      util.log(team);
      if(err) {
        util.log("Error occured");
      }
      if(!team) { 
        util.log("The team does not exist");
      }
      var match = new Match({
        hometeam: team._id
      });
      match.save(function(err) {
        if(err) {
          util.log('Error while saving Match: ' + util.inspect(err));
          res.send("An error occured whilst saving the match");
        } else {
          res.send("Saved the match");
        }
      });
    });
  });

但我想做的是能够用以下内容保存匹配

var match = new Match({
    hometeam: homeTeam._id,
    awayteam: awayTeam._id
});

有人有什么想法吗？

以下是相关代码：

JavaScript

submitMatch = function(){
    var homeId = $("#homeTeamList").val();
    var awayId = $("#awayTeamList").val();

    //alert("home: " + homeId + " away: " + awayId);

    // Frontend sends the data
    var matchForm = {
        homeKey : $('#homeTeamList').val(),
        awayKey : $('#awayTeamList').val()
    };

    // Basic validation
    $.post('/save/match', {'matchForm' : matchForm}, function(response) {
        console.log(response);
    });

};

/保存/匹配

  app.post('/save/match', function(req, res) {
    util.log('Serving request for url [GET] ' + req.route.path);
    // Output to console to test what is being passed to Save Match
    // Entire body passed to console
    //console.log('body: ', req.body);
    // Entire matchForm from body
    //console.log('matchForm: ', req.body.matchForm);
    // Home Key from matchForm
    //console.log('homeKey: ', req.body.matchForm.homeKey);
    // Away Key from matchForm
    //console.log('awayKey: ', req.body.matchForm.awayKey);

    // Get data from match Form
    var matchForm = req.body.matchForm;

    // Check if a match with 2 teams has been submitted
    if(matchForm.homeKey === '' || matchForm.homeKey === undefined ||
        matchForm.awayKey === '' || matchForm.awayKey === undefined){
      // Not a valid match
      util.log('Not valid match');
    } else {
      var homeId = matchForm.homeKey;
      var awayId = matchForm.awayKey;

      var homeTeam = Team.findByKey(homeId, function(err, homeTeam) {
        util.log(homeTeam);
        if(err) {
          util.log("Error occured");
        }
        if(!homeTeam) { 
          util.log("The home team does not exist");
        }
      });

      var match = new Match({
        hometeam: homeTeam._id
      });

      //util.log(match);

    }
  });

Answer 1

在/save/match 中，在回调设置之前，您在Match 构造函数中使用homeTeam 的值。您需要在主队和客队 findByKey 回调中创建 Match，如下所示：

Team.findByKey(homeId, function(err, homeTeam) {
  util.log(homeTeam);
  if(err) {
    return util.log("Error occured");
  }
  if(!homeTeam) { 
    return util.log("The home team does not exist");
  }

  Team.findByKey(awayId, function(err, awayTeam) {
    util.log(awayTeam);
    if(err) {
      return util.log("Error occured");
    }
    if(!awayTeam) { 
      return util.log("The away team does not exist");
    }

    var match = new Match({
      hometeam: homeTeam._id,
      awayteam: awayTeam._id
    });
  });
});

要在保持代码井井有条的同时并行查找主队和客队，您需要考虑使用流控制库，例如 async。