Question

I have two datasets returning to two different backbone collections each using a different model. Both models share a field that could be used to link them.

The second ajax call is made after the first has loaded, as a sort of pre-loader.

Upon the second collection being successfully fetched (on ‘reset’ event), I’d like to somehow bind/join models (or simply copy the JSON in, it’s a one way read only thing) with the same value for the common field to a property on each of the other models where there is a match.

Just re-read that and I don’t think it reads very well, but hopefully you understand…

Collection 1

[
  {
    foo: 'text',
    bar: 'xxx'
  },
  {
    foo: 'text',
    bar: 'yyy'
  }
]

Collection 2

[
  {
    prop1: 'a',
    prop2: 'b',
    bar: 'xxx'
  }
]

Whether the raw data is added or a binding established, I desire the collection 1 JSON to be able to read like this

[
  {
    foo: 'text',
    bar: 'xxx',
    prop1: 'a',
    prop2: 'b',
  },
  {
    foo: 'text',
    bar: 'yyy'
  }
]

Or

[
  {
    foo: 'text',
    bar: 'xxx',
    extraProps: {
      prop1: 'a',
      prop2: 'b'
    }
  },
  {
    foo: 'text',
    bar: 'yyy'
  }
]

Any help greatly appreciated. All the ways I’m thinking it could be achieved don’t seem very backboney

PS: I’ve just noticed a backbone-relational tag while tagging this question. I’ll have a read there and post back if I see anything useful. It’s quite a hard question for form a good search phrase for…

EDIT

Thanks for the replies, I popped away to write a quick script and noticed that I had some replies before I’d even finished. Anyway, just for reference I will add my initial, perhaps quite bodgy script. Please ignore the fact that mailing/mailing_id don’t have the same field name, I am not in control of the data sources at this time…

<script>
var matches = 0;
_.each(clicks.models, function(click) {
  _.each(mailshots.models, function(mailshot){
    if(click.get('mailing') == mailshot.get('mailing_id')){
      matches++;
      click.set('subject',mailshot.get('mailing_subject'));
    }
  });
});
if(matches) clicks.trigger('reset');
</script>

Anyway, that works. But I’m just going to test the first reply and have a glance at backbone-relational. Might be more than I need now but looks interesting…

Answer 1

when the two collections have been loaded you can do something like this

_(collection2).each(function(v,i){
 var model = collection1.where({bar:v.get("bar")}).first();// assuming values of bar are unique
 model.set("prop1",v.get("prop1"));
 model.set("prop2",v.get("prop2"));
})

and to be more dynamic

 _(collection2).each(function(v,i){
     var model = collection1.where({bar:v.get("bar")}).first();// assuming values of bar are unique
     _.each(_.keys(v),function(k){
          model.set(v,v.get(k));
        });
})