can I add new property when create new doc in mongoose?

Question

I have this schema (for example):

var WordSchema = new Schema({
    word: {
        type: String
    }
});
module.exports = mongoose.model('Word', WordSchema);

How I can add new property when create new doc in mongoose? something like this:

let Word = require("../models/word");
let initWord = "hello";
word = new Word({
   word: initWord,
   length: initWord.length
});

word.save(function(error) {
  if (error) {  
    //some code              
  } else {
    //some code              
  }
});

But this does not work

Answer 1

By default Mongoose doesn't allow you to dynamically add fields to your document.

But, if you create the schema with the strict option set to false, you can:

var WordSchema = new Schema({
word: {
    type: String
}
}, {strict: false});

In order to get at a property that's not in the schema you need to use a special getter form:

doc.get('length')

Or convert the document into a plain old javascript object by calling:

doc.toObject()

on the retrieved schema object.