Remove elements from array attributes of a Backbone model

Question

My model is

var Storage = Backbone.Model.extend({
    defaults: {
        q_category_id : 2,
        dimension: []
    }
});

I have a model instance named storageInfo filled with

{
    "q_category_id":2,
    "dimension":[
        {"q_id":1,"q_text":"...","data_type":"1","meta":"15","answer":"152"},
        {"q_id":2,"q_text":"...","data_type":"1","meta":"30","answer":"302"},
        {"q_id":3,"q_text":"...","data_type":"1","meta":"60","answer":"602"}
    ]
}

but before sending to the server I want the model to be like this:

{
    "q_category_id":2,
    "dimension":[
        {"q_id":1,"answer":"152"},
        {"q_id":2,"answer":"302"},
        {"q_id":3,"answer":"602"}
    ]
}

How can I remove attributes like q_text, datatype and meta from the dimension array of my model?

Careful with mutable objects in defaults, the references are copied into new models as needed rather than cloned so your dimension array is subject to surprising reference sharing. defaults: function() { return { ... } } is a better approach in such cases. — mu is too short
– mu is too short, Commented Mar 4, 2014 at 18:06

net.uk.sweet · Accepted Answer · 2014-03-04 13:29:21Z

1

You can use the underscore map and pick methods to do this quite succinctly:

storageInfo.dimensions = _.map(storageInfo.dimensions, function(obj) {
    return _.pick(obj, 'p_id', 'answer');
});

edited Mar 4, 2014 at 13:29

answered Mar 4, 2014 at 13:24

net.uk.sweet

12.4k3 gold badges26 silver badges42 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

pdjota · Accepted Answer · 2014-03-04 13:32:06Z

1

You may iterate through the dimensions before saving the model, using pick as suggested by net.uk.sweet. Otherwise, try to change the toJSON method of this model so it always returns the fields you would prefer:

var Storage = Backbone.Model.extend({
   defaults: {
     q_category_id : 2,
     dimension: []
   },
   toJSON: function () {
     var dims = _.pick(this.get('dimensions'), ['q_id', 'answer']);
     return {q_category_id: this.get('q_category_id'), dimensions: dims}
   }
});

answered Mar 4, 2014 at 13:32

pdjota

3,2533 gold badges26 silver badges33 bronze badges

Collectives™ on Stack Overflow

Remove elements from array attributes of a Backbone model

2 Answers 2

Comments

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

Comments

Your Answer

Sign up or log in

Post as a guest

Related