Using underscore group by to structure my array

Question

I have an array in the following format

[
{
    "duedate": "15-feb-2014",
    "alias": "electronus",
    "agent": "anonymous",
    "name": ""
},
{
    "duedate": "15-feb-2014",
    "alias": "luminous",
    "agent": "anonymous",
    "name": ""
},
{
    "duedate": "16-feb-2014",
    "alias": "GSM",
    "agent": "anonymous",
    "name": ""
}
]

Underscore group by method allows me to group the array using the properties and in my case using due date. This will return an array like this

{
"15-Feb-2014": [
    {
        "duedate": "15-feb-2014",
        "alias": "electronus",
        "agent": "anonymous",
        "name": ""
    },
    {
        "duedate": "15-feb-2014",
        "alias": "luminous",
        "agent": "anonymous",
        "name": ""
    }
],
"16-Feb-2014": [
    {
        "duedate": "16-feb-2014",
        "alias": "GSM",
        "agent": "anonymous",
        "name": ""
    }
]
}

Is there a possibility that I could have an array like this:

[
{
    "duedate": "15-feb-2014",
    "myValues": [
        {
            "duedate": "15-feb-2014",
            "alias": "electronus",
            "agent": "anonymous",
            "name": ""
        },
        {
            "duedate": "15-feb-2014",
            "alias": "luminous",
            "agent": "anonymous",
            "name": ""
        }
    ]
},
{
    "duedate": "16-feb-2014",
    "myValues": [
        {
            "duedate": "16-feb-2014",
            "alias": "GSM",
            "agent": "anonymous",
            "name": ""
        }
    ]
}
]

So I could have multiple array values inside each due date so I could parse it to fill a template which I can't change.

I have been struggling with this for quite some time. Any help would be gratefully recieved.

Answer 1

You just need to call map() after groupBy() ...

var groupedArray = _.chain(list)
                       .groupBy(function (x) { return x.duedate })
                       .map(function (value, date) { 
                           return {
                               duedate: date,
                               myValues: value
                           };
                       })
                       .value();

JS Fiddle: http://jsfiddle.net/t2tCa/