restfulapi Node.js&；猫鼬：处理错误

我想用Node.js、Express、MongoDB和Mongoose创建一个restful API

模式、模型和路线如下所示：

// Schema
var OperatorSchema = new Schema({
    name : { type: String, unique: true , required: true},
    short_name : { type: String, unique:true, required: true },
});
Operator = mongoose.model('Operator', OperatorSchema);

// My Api for Operator
app.post('/api/operators', common.createOperator);
exports.createOperator = function(req, res){
    Operator.create(req.body, function (err, operator) {
        // If failed, return error message
        if (err) {
            console.log(err);
            res.send(404, err)
        }
        else {
            res.send(operator)
        }
    })
};

我有三个问题：

1-像这样处理错误我发现传递给回调的err对象具有不同的结构，这取决于错误是来自mongoose还是mongo

// Mongo Error:
{
    "name": "MongoError",
    "err": "E11000 duplicate key error index: ussdauto.operators.$name_1  dup key: { : \"OpTest\" }",
    "code": 11000,
    "n": 0,
    "connectionId": 231,
    "ok": 1
}

// Mongoose Error:
{
    "message": "Validation failed",
    "name": "ValidationError",
    "errors": {
    "short_name": {
        "message": "Path `short_name` is required.",
        "name": "ValidatorError",
        "path": "short_name",
        "type": "required"
      }
    }
}

我不想公开关于错误的所有细节：只需要一条解释错误的消息就足够了，不需要知道它是mongoerror还是validationError。你如何管理它

2-第二个问题更具全局性：我将有多个API，每次我都需要做相同的工作：检查是否有错误，是否有一些通过JSON中的API返回错误消息，如果没有正常继续。如何仅使用一个函数来处理错误并在任何地方使用它

---

3-我来自一个python世界（事实上是Django），在那里，Tastypie是一个非常棒的模块，它自己处理所有这些东西。您知道Node.js+Express是否存在这样的模块吗？

您可以使用一个名为processMongooseError（err）的函数创建一个Utils模块（或者您喜欢的函数）。然后，您可以在函数中执行一个简单的检查，以确定错误的类型，然后返回一条简单的错误消息。下面我举了一个例子来说明我所说的

module.exports.processMongooseError = function(err) {
    if(err.name == "MongoError") {
        // mongo db error

    } else if(err.name == "ValidationError") {
        // mongoose error

    }
}

这个模块可以在你需要的任何地方使用，应该可以解决你的第二个问题

"short_name": {
        "message": "Path `short_name` is required.",

此错误是因为，在架构中，此字段是必需的

var OperatorSchema = new Schema({
    name : { type: String, unique: true , required: true},
    short_name : { type: String, unique:true, required: true },

当您未通过表单或邮递员应用程序提供任何输入时。。不能将必填字段留空

我不知道是什么模块导致了错误 但你可以通过观察错误来猜测

"name": "MongoError",
    "err": "E11000 duplicate key error

---

此错误是因为您将名称定义为唯一，但尝试再次插入相同的名称。

如果这仍然是一个问题，我将面临相同的问题，并使用此mongoose插件使错误消息更加一致。

---

该插件将接受mongodb错误并将其转换为类似mongoose的错误

如果您不想在向MongoDB发出POST请求后显示完整的错误响应，您可以使用Promissions作为模型来链接响应，并向RESTFull API的用户显示自定义内容，以获得json响应

我将为您提供一个示例，作为构建API的良好指南：

1#模式模型/api/模型/运算符

const mongoose = require('mongoose');

const OperatorSchema = new Schema({
    name : { type: String, unique: true , required: true},
    short_name : { type: String, unique:true, required: true },
});

module.exports = mongoose.model('Operator', OperatorSchema);

// let's imagine that at this point you have already set up your form somewhere in your app and you are using body-parser, you have some Headers configuration for this route.


//import the libraries to execute your CRUD

const express = require('express');
const router = express.Router();
const mongoose = require('mongoose');
const bodyParser = require('body-parser');//generates json structure from incoming form post
app.use(bodyParser.urlencoded({extended: false}));
app.use(bodyParser.json());

const Operators = require('../api/models/operators');

router.post('/api/operators', (req, res, next) => {

    const operator = new Operator({
        _id: new mongoose.Types.ObjectId(),
        name: req.body.name, //get the form field of "operator" using body-parser
        short_name: req.body.short_name // other fiels... from the Schema model
    }); // Build an object to store to the database using the schema set up

    // The following chain method returns a promise which you can build your custom responses for this post,
    // This chain method can be used for POST GET and DELETE requests 

    operator.save().then(result => {
        res.status(201).json({
            message: "Operator Created", //
            result: result // the "result" object can be filtered or you can simply return the message
        });

        // THE RESULT OBJECT PROPERTIES YOU CAN FILTER ON RETURN
        //  "result" : {
        //      name: "some operator name",
        //      short_name: "short guy",
        //      __v : 0,
        //      _id : "mongodb-id-generated"
        // }

    }).catch(err => {
        console.log(err);
        res.status(500).json({
            error: err 
        });
    });

}); // #### POSTS NEW OPERATORS

2#操作员积垢文件（后期）处理。/api/routes/Operator

const mongoose = require('mongoose');

const OperatorSchema = new Schema({
    name : { type: String, unique: true , required: true},
    short_name : { type: String, unique:true, required: true },
});

module.exports = mongoose.model('Operator', OperatorSchema);

// let's imagine that at this point you have already set up your form somewhere in your app and you are using body-parser, you have some Headers configuration for this route.


//import the libraries to execute your CRUD

const express = require('express');
const router = express.Router();
const mongoose = require('mongoose');
const bodyParser = require('body-parser');//generates json structure from incoming form post
app.use(bodyParser.urlencoded({extended: false}));
app.use(bodyParser.json());

const Operators = require('../api/models/operators');

router.post('/api/operators', (req, res, next) => {

    const operator = new Operator({
        _id: new mongoose.Types.ObjectId(),
        name: req.body.name, //get the form field of "operator" using body-parser
        short_name: req.body.short_name // other fiels... from the Schema model
    }); // Build an object to store to the database using the schema set up

    // The following chain method returns a promise which you can build your custom responses for this post,
    // This chain method can be used for POST GET and DELETE requests 

    operator.save().then(result => {
        res.status(201).json({
            message: "Operator Created", //
            result: result // the "result" object can be filtered or you can simply return the message
        });

        // THE RESULT OBJECT PROPERTIES YOU CAN FILTER ON RETURN
        //  "result" : {
        //      name: "some operator name",
        //      short_name: "short guy",
        //      __v : 0,
        //      _id : "mongodb-id-generated"
        // }

    }).catch(err => {
        console.log(err);
        res.status(500).json({
            error: err 
        });
    });

}); // #### POSTS NEW OPERATORS

---

我在相当长的一段时间内使用了这个过程，允许开发人员将内容发布到API是非常有效的，如果他们出现错误，我会向他们展示他们需要什么来更好地阐述他们的请求

如果你每篇文章只问一个问题，效果会更好。