Mongoose：如何替换子文档数组？

I have set up a user schema with mongoose which contains a subdocument "contacts". The subdocument "contacts" is a collection of contacts objects which contain the actual contact (reference to another user object) and some data which is related to the "friendship".

我已经设置了一个用mongoose的用户模式，其中包含一个子文档“contacts”。子文档“contacts”是联系人对象的集合，其包含实际联系人（对另一个用户对象的引用）和一些与“友谊”相关的数据。

In my front-end application I can now manage the contacts by adding or removing users to my contact list. The front-end saves these changes as HTTP PUT requests to the server.

在我的前端应用程序中，我现在可以通过在我的联系人列表中添加或删除用户来管理联系人。前端将这些更改保存为HTTP PUT请求到服务器。

The PUT request contains the whole user object which more or less replaces the user object on the database. Unfortunately it is not possible to replace subdocument collection. You only can push new ones or remove them.

PUT请求包含整个用户对象，它或多或少地替换数据库上的用户对象。不幸的是，无法替换子文档集合。您只能推送新的或删除它们。

Here are the schemas:

这是模式：

var UserSchema = new Mongoose.Schema({

    username: { 
        type: String, 
        index: { unique: true, sparse: true }, 
        required: true, lowercase: true, trim: true
    },

    email: {
        type: String,
        index: { unique: true, sparse: true }, 
        required: true, lowercase: true, trim: true
    },

    contacts: [ContactSchema]

});

var ContactSchema = new Mongoose.Schema({

    user: {
        ref: "User",
        type: Mongoose.Schema.ObjectId
    },

    isContact: {
        type: Boolean,
        default: true
    }

});

Currently I try to replace the contacts by removing all and adding the one in the request:

目前我尝试通过删除所有并在请求中添加一个来替换联系人：

app.put('/me', loadUser, function(req, res, next) {
    var user = req.user;

    req.user.contacts.forEach(function(contact) {
        req.body.contacts.forEach(function(contact) {
            contact.remove();
        });
    });

    req.body.contacts.forEach(function(contact) {
        req.user.contacts.push(contact);
    });

    user.save(function(err, user) {
        if (err) return next(err);
        res.send(200);
    });
});

Has somebody actually an better idea how I can update this subdocument collection to the state in the request?

有人真的更好地了解如何将此子文档集合更新为请求中的状态？

1 个解决方案

#1

You can use the _underscore library to filter (reject) the object you want to remove

您可以使用_underscore库来过滤（拒绝）要删除的对象

Here an example how to remove something from an array without foreach.

这是一个如何在没有foreach的情况下从数组中删除内容的示例。

var _und = require('underscore');

var array = [{_id:1, title:'object one'}, {_id:2, title:'object two'}, {_id:3, title: 'object three' }]
    the_target = 'object two';
    new_array = _und.reject(array, function(item){
       return item.title === target;
    })

The expected result should be:

预期结果应该是：

=> [{_id:1, title:'object one'}, {_id:3, title:'object three'}]

If you know the id, even better.

如果你知道id，那就更好了。

All you have to do then is empty your subdocs by doing this:

所有你需要做的就是通过这样做来清空你的subdocs：

var mytargetarray = [];
    mytargetarray.push(new_array);
    mytargetarray.save();

If you want to replace the whole subdoc array, why not just replacing them:

如果要替换整个子数组，为什么不直接替换它们：

req.user.contacts = [];
req.user.contacts.push(req.body.contacts);

save and done.

保存完成。

Hope that helps a bit.

希望有点帮助。

Just a hint, in mongodb you work with object arrays, you can simple replace every value:

只是一个提示，在mongodb中你使用对象数组，你可以简单地替换每个值：

// active data from database
user.name = 'test user';
// now just give the object a new value
user.name = 'new name';
// and save .. done
user.save();

#1