"refPath" doesn't work for virtuals?

[miliu99]

I love the "refPath" instead of "ref" for dynamic population. This works great.

    var activitySchema = new Schema({
        refId: {type: Schema.ObjectId, refPath: 'refKind'},
        refKind: String
    };

However, I don't like to share the same field "refId" for either id or the object. So, I found a great solution using virtuals. However, to my dismal, the "refPath" doesn't seem to work for virtuals, although "ref" works.

var activitySchema = new Schema({
      refId: {type: Schema.ObjectId},
      refKind: String
  }, { _id: false, toObject: {virtuals: true}, toJSON: { virtuals: true }});
  activitySchema.virtual('refObj', {refPath: 'refKind', localField: 'refId', foreignField: '_id', justOne: true});

I understand that nothing is mentioned in the document about using refPath in virtuals, so I'm not sure if this is just not supported or a bug. Here is something I tried that doesn't work. Any clue?

Oh, I'm using v4.10.8. Not sure if it is working in 4.11.9 because I run into other problems (DeprecationWarning: open() is deprecated in mongoose >= 4.11.0, use openUri() instead, or set the useMongoClient option if using connect() or createConnection().) when trying to use the latest version, so I have to roll back.

[vkarpov15]

Definitely a feature we need to add, thanks for the suggestion.

Also, to get rid of the warning add useMongoClient: true, like mongoose.connect(MONGO_URI, { useMongoClient: true })

[vkarpov15]

In order to be more consistent with the API for #5704, defaults, etc. we'll instead support setting ref to a function in your virtual with the doc as the context. So instead of:

  activitySchema.virtual('refObj', {refPath: 'refKind', localField: 'refId', foreignField: '_id'});

You will have to do

activitySchema.virtual('refObj', {ref: function() { return this.refKind; }, localField: 'refId', foreignField: '_id'});

Should make for a cleaner API, we'll consider doing this for regular refPath as well.

[p3x-robot]

how come the refObj in above that works instead of giving an object it is an array, even though it can match 1 unique doc, how come?

[vkarpov15]

@p3x-robot I don't understand your question, can you please clarify with some code samples?

[p3x-robot]

@vkarpov15 hello! how are you?
so refPath virtual is not working:

const mongoose = require('mongoose');
const Schema = mongoose.Schema;

const _ = require('lodash');

const PdfFile = new Schema({
    docType: {
        type: String,
        index: true,
    },
    docId: {
        type: Schema.ObjectId,
        index: true,
        refPath: 'docTypeModelName'
    },
    buffer: {
        type: Buffer,
    }
},{
    timestamps: true
});

// not working
PdfFile.virtual('docTypeModelName').get(function () {
    const docTypeModelName = _.pascalCase(this.docType);
    console.log('docTypeModelName', docTypeModelName)
    return docTypeModelName
});

// working
PdfFile.virtual('doc', {
    ref: function() {
        const ref = _.pascalCase(this.docType)
        console.warn('PdfFile.virtual ref', ref)
        return ref;
    },
    localField: 'docId',
    foreignField: '_id'
});

module.exports = PdfFile;

How come with using refPath as virtual is not working?
It took me 2 days to find as a virtual with ref.

[vkarpov15]

@p3x-robot I opened up a new issue to track this ☝️