如何使用猫鼬根据用户ID保存文档？

Question

I am trying to save template based on user id , How can i make sure when template save it save with user id _id ? i added reference to the templateSchema for User .

user.model.js

var UserSchema = new mongoose.Schema({
  _id: { type: String, required: true, index: {unique: true}},
  firstName: String,
  lastName: String,
  type: String,
  groups:[{type: String, ref: 'Group', required: false}]
},
  {
    toObject: {
      virtuals: true
    },
    toJSON: {
      virtuals: true
    }
  });

export default mongoose.model('User', UserSchema);

template.model.js

var User = require('../user/user.model.js');

var TemplateSchema = new mongoose.Schema({
  _id: { type: String, required: true},
  name: String,
  id: String,
  appliesTo: [],
  properties: [],
  createdBy: { type: mongoose.Schema.Types.ObjectId, ref: 'User'}
 });


export default mongoose.model('Templates', TemplateSchema);

template.controller.js

var eTemplate = require('./template.model');

export function create(req, res) {
  console.log(req.body);
  eTemplate.createAsync(req.body)
    .then(responseWithResult(res, 201))
    .catch(handleError(res));
}

Answer 1

Mongoose has two built-in functions that are called before (pre) and after (post) you save a document. My advice is to make use of them. Here is an example of my code in which I search for an sequence number before saving the user document. You can do the same: When you save the template, make a request for the user id to the database (Or vice-versa). You can even save one, get the id and save the other.

Bellow follows my code for the sequence and the user.

var UserSchema   = new Schema({
username: { type: String, required: true, unique: true },
id: { type: String },
...
});

UserSchema.pre('save', function(next) {
  let doc = this;     
  let id = 'userSeq'    

  Sequence.findByIdAndUpdate(id, { $inc : {nextSId : 1} },  function(error,data) {         
    if(error)
      next(error)               
    doc.id = data.nextSId-1;
    next();
  })        
});

I hope my answer was useful for you. Just a remark, pre and post are not called in the event of updates for the document.