postman POST請求正在正確填充數據庫，但在寫入文件時獲取空值

Question

我的一個節點控制器出現了一個奇怪的問題。對於上下文，在針對此特定控制器的POST請求上，我將對象存儲在mongo數據庫中，並將對象的必要部分寫入文件。有一個網站已經存在，它直接與服務器連接，但我正在爲想要定製界面的客戶編寫REST API。 （我沒有寫節點服務器或網站。）

我的問題是，由於某種原因，在這種情況下寫入文件的值在通過「post」後如下Null： { 「腿」：[{ 「PTU」：{ 「傾斜」：{}， 「PAN」：{}}}，{ 「音頻」：{ 「靜音」：假， 「體積」：0}， 「PTU」： { 「傾斜」：{ 「ABS」：NULL} 「鍋」：{ 「ABS」：空}}}，{ 「音頻」：{ 「靜音」：真， 「體積」：0}， 「PTU」： {「tilt」：{「abs」：null}，「pan」：{「abs」：null}}}]}

但是，網站上的表單填充正確，如果我按「保存」網站，文件被正確更新。即

{"legs":[{"ptu":{"tilt":{"abs":0},"pan":{"abs":0}}},{"audio":{"track":"/home/rahd/ult0316-p002/resources/tracks/Maid with the Flaxen Hair.mp3","vol":0,"mute":false},"ptu":{"tilt":{"abs":10},"pan":{"abs":10}}},{"audio":{"track":null,"vol":0,"mute":true},"ptu":{"tilt":{"abs":10},"pan":{"abs":10}}}]} 

這裏是正在發送的原始JSON我的郵遞員要求：

{   
    "name": "NicksCoolTour3", 
    "location": "/home/rahd/ult0316-p002/resources/tours/5982374cb492c516c20c40d0.json", 
    "legs": [ 
     { 
       "audio": { 
       "mute": true, 
       "volPercent": 0, 
       "vol": -120, 
       "track": null 
      }, 
      "ptu": { 
       "poi": "59823726b492c516c20c40cd", 
       "tilt": { 
        "vel": 5, 
        "rel": 0, 
        "abs": 0 
       }, 
       "pan": { 
        "vel": 5, 
        "rel": 0, 
        "abs": 0 
       }, 
       "direction": "quickest" 
      }, 
      "time": 0, 
      "velMode": "time", 
      "ptuMode": "poi" 
     }, 
     { 
      "_id": "5982374cb492c516c20c40d2", 
      "audio": { 
       "mute": false, 
       "volPercent": 100, 
       "vol": -120, 
       "track": "5983222d79930a1dbd4d94ac" 
      }, 
      "ptu": { 
       "tilt": { 
        "vel": 5, 
        "rel": 10, 
        "abs": 0 
       }, 
       "pan": { 
        "vel": 5, 
        "rel": 10, 
        "abs": 0 
       }, 
       "direction": "quickest" 
      }, 
      "time": 0, 
      "velMode": "time", 
      "ptuMode": "rel" 
     }, 
     { 
      "_id": "5982374cb492c516c20c40d1", 
      "audio": { 
       "mute": true, 
       "volPercent": 100, 
       "vol": -120, 
       "track": "59823711b492c516c20c40cc" 
      }, 
      "ptu": { 
       "tilt": { 
        "vel": 5, 
        "rel": 0, 
        "abs": 0 
       }, 
       "pan": { 
        "vel": 5, 
        "rel": 0, 
        "abs": 0 
       }, 
       "direction": "quickest" 
      }, 
      "time": 0, 
      "velMode": "time", 
      "ptuMode": "rel" 
     } 
    ] 
} 

，這裏是我的帖子控制器：

router.post('/',function (req, res, next){ 
    var new_tour = new Tour(req.body); 
    new_tour._id = new mongoose.Types.ObjectId; 
    new_tour.save(function(err, tour) { 
     if (err) return next(err); 
     res.json({ message: "tours database sucessfully updated" }); 
    }); 
    }); 

我不知道這可能是導致這看起來似乎數據庫正在獲取正確的值，但向文件寫入請求的函數表現得不正確。

這裏是處理文件寫入的模式：在您的異步功能

var mongoose = require("mongoose") 
    , fs = require('fs') 
    , path = require('path') 
    , resources = require(path.join(__dirname, '..', '..', 'config', 'resources')); 

var schema = new mongoose.Schema({ 
    name: { type: String, default: '', unique: true, required: true }, 
    location: { type: String }, 
    legs: [{ 
     ptuMode: { type: String, default: 'abs' }, // abs || rel || poi 
     velMode: { type: String, default: 'vel' }, // vel || time 
     time: { type: Number, default: 0 }, // vel || time 
     ptu: { 
      direction: { type: String, default: 'cw' }, // cw || ccw 
      pan: { 
       rel: { type: Number }, 
       abs: { type: Number }, 
       vel: { type: Number }, 
      }, 
      tilt: { 
       rel: { type: Number }, 
       abs: { type: Number }, 
       vel: { type: Number }, 
      }, 
      poi: { 
       type: mongoose.Schema.Types.ObjectId, 
       ref: 'POI' 
      }, 
     }, 
     audio: { 
      mute: { type: Boolean }, 
      vol: { type: Number }, 
      volPercent: { type: Number }, 
      track: { 
       type: mongoose.Schema.Types.ObjectId, 
       ref: 'Track' 
      }, 
     } 
    }] 
}, 
    { 
     timestamps: true 
    }); 

schema.pre('save', function (next) { 
    var tour = this; 
    if (!tour.location || tour.location.length < 1) { 
     tour.location = path.join(resources.tours, tour._id + '.json'); 
    } 

    tour.writeToFile(function (err) { 
     console.error(err); 
    }); 

    next(); 
}); 

schema.post('remove', function (tour) { 
    if (tour.location && tour.location.length > 0) { 
     fs.exists(tour.location, function (exists) { 
      if (exists) { 
       fs.unlink(tour.location); 
       console.log('Deleted Tour: ' + tour.location); 
      } else { 
       console.log('Tour not found, so not deleting file.'); 
      } 
     }); 
    } 
}); 

schema.methods.writeToFile = function (callback) { 

    function saveToFile(tour, callback) { 
     var filePath = tour.location; 
     var name = tour.name; 
     delete tour.location; 
     delete tour.name; 
     delete tour.createdAt; 
     delete tour.updatedAt; 
     delete tour._id; 
     delete tour.__v; 

     for (li in tour.legs) { 
      var leg = tour.legs[li]; 
      var index = li; 
      if (typeof index === 'string') { 
       index = parseInt(li); 
      } 

      delete leg._id; 

      // Delete rel, force abs 
      delete leg.ptu.tilt.rel; 
      delete leg.ptu.pan.rel; 

      if (leg.audio.hasOwnProperty("volPercent")) { 
       var x = leg.audio.volPercent; 
       delete leg.audio.volPercent; 
       var n = -120; 
       if (x > 0) { 
        var val = Math.pow((x/100), 4); 
        n = Math.max(20 * Math.log10(val), -120) 
       } 
       leg.audio.vol = n; 
      } 

      if (index == 0) { 
       delete leg.ptu.pan.vel; 
       delete leg.ptu.tilt.vel; 

      } else { 
       if (leg.ptu.pan.vel == 0) { 
        leg.ptu.pan.vel = 50; 
       } 

       if (leg.ptu.tilt.vel == 0) { 
        leg.ptu.tilt.vel = 50; 
       } 

       if (leg.ptu.direction === 'ccw') { 
        leg.ptu.pan.vel = -(Math.abs(leg.ptu.pan.vel)); 
       } 
      } 

      if (leg.ptu.direction === 'quickest') { 
       delete leg.ptu.tilt.vel; 
       delete leg.ptu.pan.vel; 
      } 

      if (typeof (leg.audio.track) === 'object' && leg.audio.track !== null) { 
       leg.audio.track = leg.audio.track.location; 
      } 

      // Handle Delay 
      if (leg.ptuMode == 'delay') { 
       delete leg.ptu.pan; 
       delete leg.ptu.tilt; 
      } else { 
       delete leg.ptu.delay; 
      } 

      delete leg.ptu.poi; 
      delete leg.time; 
      delete leg.ptu.direction; 
      delete leg.ptuMode; 
      delete leg.velMode; 
      if (index == 0) { 
       delete leg.audio; 
      } 
     } 

     if (filePath && filePath.length > 0) { 
      fs.writeFile(filePath, JSON.stringify(tour), function (err) { 
       if (err) { 
        if (callback) callback(err); 
        return console.error(err); 
       } 
       console.log("Tour Written: " + name); 
      }); 
     } else { 
      console.error("Tour location empty: " + name); 
     } 

    } 

    var tour = this.prepareExport(); 

    saveToFile(tour, callback); 
}; 

schema.methods.prepareExport = function() { 
    // TODO: Ensure Track and POI are loaded 
    var tour = this.toObject(); 
    var prevLeg = false; 

    // Calculate proper abs positions before prepare for export 
    for (li in tour.legs) { 
     var leg = tour.legs[li]; 
     if (leg.ptuMode == 'poi') { 
      leg.ptu.pan.abs = leg.ptu.poi.pan; 
      leg.ptu.tilt.abs = leg.ptu.poi.tilt; 
     } else if (leg.ptuMode == 'rel' && prevLeg) { 
      leg.ptu.pan.abs = prevLeg.ptu.pan.abs + leg.ptu.pan.rel; 
      leg.ptu.tilt.abs = prevLeg.ptu.tilt.abs + leg.ptu.tilt.rel; 
     } 
     if (leg.ptuMode !== 'delay') { 
      prevLeg = leg; 
     } 
    } 

    // Calulcate degrees per second for each leg 
    prevLeg = false; 
    for (li in tour.legs) { 
     var leg = tour.legs[li]; 
     if (prevLeg && leg.velMode == 'time') { 
      var time = Math.abs(leg.time) || 0; 
      if (time > 0) { 
       if (leg.ptuMode == 'delay') { 
        leg.ptu.delay = time; 
       } else if (leg.ptuMode == 'rel') { 
        leg.ptu.pan.vel = leg.ptu.pan.rel/time; 
        leg.ptu.tilt.vel = leg.ptu.tilt.rel/time; 
       } else { 
        leg.ptu.pan.vel = (leg.ptu.pan.abs - prevLeg.ptu.pan.abs)/time; 
        leg.ptu.tilt.vel = (leg.ptu.tilt.abs - prevLeg.ptu.tilt.abs)/time; 
       } 
      } else { 
       leg.ptu.pan.vel = 0; 
       leg.ptu.tilt.vel = 0; 
      } 

      leg.ptu.pan.vel = Math.abs(leg.ptu.pan.vel); 
      leg.ptu.tilt.vel = Math.abs(leg.ptu.tilt.vel); 

      if (leg.ptu.direction === 'ccw') { 
       leg.ptu.pan.vel = -leg.ptu.pan.vel; 
      } 

      // Vel bounds 
      if (leg.ptu.pan.vel > 50) { 
       leg.ptu.pan.vel = 50; 
      } else if (leg.ptu.pan.vel < 5 && leg.ptu.pan.vel > 0) { 
       leg.ptu.pan.vel = 5; 
      } 
      if (leg.ptu.tilt.vel > 50) { 
       leg.ptu.tilt.vel = 50; 
      } else if (leg.ptu.tilt.vel < 5 && leg.ptu.tilt.vel > 0) { 
       leg.ptu.tilt.vel = 5; 
      } 

      // Quickest was using 50ยบ/s, but should be omitted 
      if (leg.ptu.direction === 'quickest' && time === 0) { 
       delete leg.ptu.pan.vel; 
       delete leg.ptu.tilt.vel; 
      } 

      // Remove invalid tilt velocity when tilt diff is 0 so vector vel on control server is calculated correctly 
      if (prevLeg.ptu.tilt.abs - leg.ptu.tilt.abs == 0) { 
       delete leg.ptu.tilt.vel; 
      } 
     } 
     prevLeg = leg; 
    } 
    return tour; 
}; 

/* bounds logic 

if (leg.ptu.pan.abs > 180) { 
    leg.ptu.pan.abs = leg.ptu.pan.abs - 360; 
} else if (leg.ptu.pan.abs < -180) { 
    leg.ptu.pan.abs = leg.ptu.pan.abs + 360; 
} 

if (leg.ptu.tilt.abs > 90) { 
    leg.ptu.tilt.abs = 90; 
} else if (leg.ptu.tilt.abs < -90) { 
    leg.ptu.tilt.abs = -90; 
} 
*/ 

var Tour = mongoose.model("Tour", schema); 

module.exports = Tour; 

Answer 1

有錯誤：

schema.pre（「保存」，函數（下一個），接下來必須有我在回調函數

tour.writeToFile(function (err) { 
    console.error(err); 
    next(); 
}); 

schema.methods.writeToFile =函數（回調）：你不僅要在錯誤

成功返回回調和

if (filePath && filePath.length > 0) { 
     fs.writeFile(filePath, JSON.stringify(tour), function (err) { 
      if (err) { 
       if (callback) callback(err); 
       return console.error(err); 
      } 
      else 
      { 
       console.log("Tour Written: " + name); 
       if (callback) callback(err); 
      } 

     }); 
    } else { 
     console.error("Tour location empty: " + name); 
     if (callback) callback(err); 
    }