CODEWITHSUNDEEP
javascriptbackbone.js
Evan Emolo
Evan Emolo

Reputation: 1670

Backbone filter through an array of arrays to match a string

I am having trouble wrapping my head around how to implement the following:

I have a MongoDB Schema like so:

var DocumentSchema = new Schema({
  num: Number,
  authors: [String]
})

Which is being used for the backend for a Backbone collection. I am having trouble understanding how to filter through each document's authors array to match a username.

Something like:

var DocumentCollection = Backbone.Collection.extend({
  model: Document,

  match_username: function() {
    var username = 'foo'
    // match username to author...
    })
  }
});

To summarize, I would be filtering through the authors array for each document in the collection to check if there is a username match. If the username matches, get num and store in a new array to be returned.

What is the most efficient way of going about this?

Upvotes: 0

Views: 173

Answers (1)

kalley
kalley

Reputation: 18462

If I understand you correctly, it sounds like what you need is:

var DocumentCollection = Backbone.Collection.extend({
    model: Document,

    match_username: function() {
        var username = 'foo'
        return this.chain().filter(function(doc) {
            return _.indexOf(doc.get('authors'), username) > -1;
        }).map(function(doc) {
            return doc.get('num');
        }).value();
    }
});

It's filtering using _.indexOf on the authors, then _.map on the num of the filtered collection.

fiddle

Upvotes: 1

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