lackey-mongoose-ensure-object-ids

Mongoose ensure object ids

Cleans up an object so that all properties that were defined as being a ref in the schema hold a valid ObjectId instead of the provided value.

Let's assume this is your schema:

    {
        title: String,
        tags: [{
            type: Schema.Types.ObjectId,
    	    ref: 'tag'
        }]
    }

If your GET routes use mongoose populate this is the objects your users will see:

    {
        "_id": "5583e7eb4e6c66874b90ff70"
        "title": "test document"
        "tags": [
            {
                "_id": "5583e7eb4e6c66874b90ff71"
                "name": "my test tag",
                "slug": "my-test-tag"
            }
        ]
    }

Bu trying to submit that into mongoose will issue a CastError: 'Cast to ObjectId failed for value "xxxxxxx" at path "xxxxxx"'

By using our plugin the object would be converted into:

    {
        "_id": "5583e7eb4e6c66874b90ff70"
        "title": "test document"
        "tags": ["5583e7eb4e6c66874b90ff71"]
    }

_id or id are searched in the tag object and returned in its place.

Basic usage

Add the plugin to a Mongoose schema:

var ensureObjectIds = require('lackey-mongoose-ensure-object-ids'), 
    mongoSchema = new Schema({
        title: String,
        tags: [{
       		type: Schema.Types.ObjectId,
   	    	ref: 'tag'
        }]
    });

mongoSchema.plugin(ensureObjectIds);

Then use it on the controller:

router.post('/',
    handler(handlerOptions, function (o) {
        o.getBody()
            .then(Product.ensureObjectIds)
            .then(function (doc) {
                Product
                    .create(doc)
                    .then(o.formatOutput('_id:id'))
                    .then(o.handleOutput())
                    .then(o.handle404(), o.handleError());
            }, o.handleError());
    }));

The previous example uses our request handler. A more simple example, without the request handler would look something like this:

Product
    .ensureObjectIds(req.body)
    .then(function (doc) {
        Product.create(doc, function(err){
            // do something with the error...
            // or reply to the request
        });
    }, function (err) {
        // do something with the error...
    });

With Options - Searching for ids

Our basic example assumes we were provided with an object that contains either an id or an _id property. To allow any other property that is unique, like a slug or a code, we would have to search the database to recover the ObjectId.

Setting the plugin:

mongoSchema.plugin(ensureObjectIds, {
    // key: Model name
    // value: Space separated field names
    tag: 'slug code'
});

By providing the options we define what fields are searchable for each model. The plugin will search them using an $or query. Just be careful with collisions when using several searchable fields per model.