Mongoose find unique tags

Question

Currently saving an array of tags for each user. The issue I'm running into is how to search for unique tags (so I can do a type ahead for adding new users) Right now if I get a match, the function returns the WHOLE tags array that contain the tag fragment rather than just the individual tag of the user that matches.

How do I specify that I only want to return unique title values rather than the whole tag array?

var UserSchema = new Schema({
    username: {
        type: String,
        trim: true
    },

    tags:[
        {
        title:String
        }
    ]
});


exports.searchByTag = function(req, res) {
    var tag = req.params.tag;

        User.find({'tags.title':{ $regex: tag }}).distinct('tags.title', function(error, tags) {
        res.json(tags);
});

Answer 1

Kept cracking & figured it out. This solution uses the lodash _.filter method.

    searchTerm = 'abc'
    //search the database for unique user.tag.title 
    User.find().distinct('tags.title', function(error, tagTitles) {

        var results = _.filter(tagTitles, function(title){ 
                //use lodash to filter out the the tagTitles array built by mongoose
                //return  = push the item into the results array based on regex match of searchTerm
                return title.match(searchTerm);
            });
        //respond with the results array
        res.json(results);
    });