Virtual list creates circular reference error when trying to include virtuals in query result

Hey,

on a List register there’s a piece of code that adds ‘list’ as a virtual field.

this.schema.virtual('list').get(function () {
        return list;
    });

This creates some problems when you add your own virtuals and want them included in query result you’re going to parse to JSON (for an API endpoint for example).

Take this example:

var Waypoint = new keystone.List('Waypoint', {
    autokey: { path: 'slug', from: 'name', unique: true }
});

...


//Check if waypoint is available
Waypoint.schema.virtual('available').get(function() {
    console.log('Calling available getter');
    if(this.conditionsOn) {
        return availabilityUtils.check(this.conditions.days, this.conditions.start, this.conditions.end);
    } else {
        return true;
    }
});

...

Waypoint.schema.set('toJSON', {
    virtuals: true
});
Waypoint.addPattern('standard meta');
Waypoint.defaultColumns = 'title, type';
Waypoint.register();

In this case, querying a waypoint and returning it with res.apiResponse() calls the Object.stringify method but generates an TypeError: Converting circular structure to JSON error because of the list virtual.

Best practices or workarounds?

Kind regards, David

[ignlg]

Just in case that someone needs a quick & dirty fix for this, I’ve created a gist with a code that deletes every list inside the model prior to export it: https://gist.github.com/ignlg/519a4b6b9845d7442a48

Hope it helps meanwhile.

[Twansparant]

Thanks @ignlg for your gist, thos fixed my problem!