How can I filter an array of objects based on the value of a field and the remap the objects?

Question

I have the following object:

options.getOrderBy = function (type) {
    var OrderBy = [
        { type: 'x', id: 0, label: 'xx1', key: 'yy1' },
        { type: 'x', id: 1, label: 'xx2', key: [1,2] },
        { type: 'x', id: 9, label: 'xx2', key: ['a','b'] },
        { type: 'y', id: 0, label: 'xx44', key: 'yya' },
        { type: 'y', id: 1, label: 'xx45', key: 'yyb' },
        { type: 'y', id: 2, label: 'xx46', key: 'yyc' },
    ];
    return OrderBy;
};

What I need is that when the function is called with a type of ('x') then I want it to return something like:

[
   { id: 0, label: 'xx1', key: [1.2] },
   { id: 1, label: 'xx2', key: 'yy2' },
   { id: 9, label: 'xx2', key: ['a','b'] }
]

Can someone explain to me how I can filter an array based on the value of the type field and then just return an array of objects containing id, label and key?

Note that I have _lodash and I would like to use that if it makes it easier. Also my solution would be for browsers greater than IE9

Answer 1

My solution exploits Lodash's map and omit functions. See it here

var filter = function(collection, filterKey) {
    return _.map(collection, function(elem) {
        return _.omit(elem, filterKey);
    })        
}

Use it as:

var filtered = filter(OrderBy, 'type');

EDIT: taking into consideration also the value for filterKey

var filter = function(collection, filterKey, filterValue) {
                 return _.compact(_.map(collection, function(elem) {
                     if(elem[filterKey] === filterValue)
                         return _.omit(elem, filterKey);
                 }))        
              }

Use it as:

var filtered = filter(OrderBy, 'type', 'x');

SECOND EDIT: clearer version

var filterV2 = function(collection, filter) {
    return _(collection)
           .map(function (elem) { if(elem[filter.key] == filter.value) return _.omit(elem, filter.key) })
           .compact()
           .value()
} 

Use it as:

var filtered = filterV2(OrderBy, { key: 'type', value: 'x' });

Answer 2

options.getOrderBy = function (type) {
    var OrderBy = [
        { type: 'x', id: 0, label: 'xx1', key: 'yy1' },
        { type: 'x', id: 1, label: 'xx2', key: 'yy2' },
        { type: 'y', id: 0, label: 'xx44', key: 'yya' },
        { type: 'y', id: 1, label: 'xx45', key: 'yyb' },
        { type: 'y', id: 2, label: 'xx46', key: 'yyc' },
    ];
    return OrderBy.filter(function(e) {
        return e.type === type;
    }).map(function(e) {
        delete e.type;
        return e;
    });
};

If you could change the OrderBy structure to an object, it will be much simpler:

options.getOrderBy = function (type) {
    var OrderBy = {
      x:[ 
          { id: 0, label: 'xx1', key: 'yy1' },
          {  id: 1, label: 'xx2', key: 'yy2' }
        ],
      y:[
          { id: 0, label: 'xx44', key: 'yya' },
          { id: 1, label: 'xx45', key: 'yyb' },
          { id: 2, label: 'xx46', key: 'yyc' }
        ]
    };
    return OrderBy[type];
};

Answer 3

You can filter the order options like this:

var newOrderBy = [];
for(var i = 0, l = OrderBy.length; i < l; i++) {
  if(OrderBy[i].type == type) {
    newOrderBy.push({
      id: OrderBy[i].id,
      label: OrderBy[i].label,
      key: OrderBy[i].key
    });
  }
}

Answer 4

Using underscore.js _.filter():-

options.getOrderBy = function (type) {
var OrderBy = [
    { type: 'x', id: 0, label: 'xx1', key: 'yy1' },
    { type: 'x', id: 1, label: 'xx2', key: [1,2] },
    { type: 'x', id: 9, label: 'xx2', key: ['a','b'] },
    { type: 'y', id: 0, label: 'xx44', key: 'yya' },
    { type: 'y', id: 1, label: 'xx45', key: 'yyb' },
    { type: 'y', id: 2, label: 'xx46', key: 'yyc' },
];
var filteredOrderBy = _.filter(OrderBy, function (order) {
    if (order.type === type) {
        return true;
    } else return false;
});
return filteredOrderBy ;

};