javascript - Lodash: how do I use filter when I have nested Object?

Question

Consider this example. I am using Lodash

 'data': [
        {
            'category': {
                'uri': '/categories/0b092e7c-4d2c-4eba-8c4e-80937c9e483d',
                'parent': 'Food',
                'name': 'Costco'
            },
            'amount': '15.0',
            'debit': true
        },
        {
            'category': {
                'uri': '/categories/d6c10cd2-e285-4829-ad8d-c1dc1fdeea2e',
                'parent': 'Food',
                'name': 'India Bazaar'
            },
            'amount': '10.0',
            'debit': true
        },
        {
            'category': {
                'uri': '/categories/d6c10cd2-e285-4829-ad8d-c1dc1fdeea2e',
                'parent': 'Food',
                'name': 'Sprouts'
            },
            'amount': '11.1',
            'debit': true
        },

When I do

_.filter(summary.data, {'debit': true})

I get all the objects back.

what I want?

I want all the objects where category.parent == 'Food', how can I do that?

I tried

_.filter(summary.data, {'category.parent': 'Food'})

and got

[]

Answer 1

lodash allows nested object definitions:

_.filter(summary.data, {category: {parent: 'Food'}});

As of v3.7.0, lodash also allows specifying object keys in strings:

_.filter(summary.data, ['category.parent', 'Food']);

Example code in JSFiddle: https://jsfiddle.net/6qLze9ub/

lodash also supports nesting with arrays; if you want to filter on one of the array items (for example, if category is an array):

_.filter(summary.data, {category: [{parent: 'Food'}] }); 

If you really need some custom comparison, that's when to pass a function:

_.filter(summary.data, function(item) {
  return _.includes(otherArray, item.category.parent);
});