lodash Filter collection using array of values

问题:

I would like to filter a collection using array of property value. Given an array of IDs, return objects with matching IDs. Is there any shortcut method using lodash/underscore?

var collections = [{ id: 1, name: 'xyz' },
                   { id: 2,  name: 'ds' },
                   { id: 3,  name: 'rtrt' },
                   { id: 4,  name: 'nhf' },
                   { id: 5,  name: 'qwe' }];
var ids = [1,3,4];

// This works, but any better way?

var filtered = _.select(collections, function(c){    
    return ids.indexOf(c.id) != -1
});

回答1:

If you're going to use this sort of pattern a lot, you could create a mixin like the following, though, it isn't doing anything fundementally different than your original code. It just makes it more developer friendly.

_.mixin({
  'findByValues': function(collection, property, values) {
    return _.filter(collection, function(item) {
      return _.contains(values, item[property]);
    });
  }
});

Then you can use it like this.

var collections = [
    {id: 1, name: 'xyz'}, 
    {id: 2,  name: 'ds'},
    {id: 3,  name: 'rtrt'},
    {id: 4,  name: 'nhf'},
    {id: 5,  name: 'qwe'}
];

var filtered = _.findByValues(collections, "id", [1,3,4]);

Update - This above answer is old and clunky. Please use the answer from Adam Boduch for a much more elegant solution.

_(collections)
  .keyBy('id') // or .indexBy() if using lodash 3.x
  .at(ids)
  .value();

回答2:

A concise lodash solution that uses indexBy() and at().

_(collections)
    .indexBy('id')
    .at(ids)
    .value();

回答3:

We can also filter like this

var collections = [{ id: 1, name: 'xyz' },
            { id: 2,  name: 'ds' },
            { id: 3,  name: 'rtrt' },
            { id: 4,  name: 'nhf' },
            { id: 5,  name: 'qwe' }];



        var filtered_ids = _.filter(collections, function(p){
            return _.includes([1,3,4], p.id);
        });

        console.log(filtered_ids);

回答4:

I like jessegavin's answer, but I expanded on it using lodash-deep for deep property matching.

var posts = [{ term: { name: 'A', process: '123A' } }, 
             { term: { name: 'B', process: '123B' } }, 
             { term: { name: 'C', process: '123C' } }];

var result = _.filterByValues(posts, 'term.process', ['123A', '123C']);
// results in objects A and C to be returned

jsFiddle

_.mixin({
    'filterByValues': function(collection, key, values) {
        return _.filter(collection, function(o) {
            return _.contains(values, resolveKey(o, key));
        });
    }
});

function resolveKey(obj, key) {
    return (typeof key == 'function') ? key(obj) : _.deepGet(obj, key);
}

If you don't trust lodash-deep or you want support for properties that have dots in their names, here's a more defensive and robust version:

function resolveKey(obj, key) {
    if (obj == null || key == null) {
        return undefined;
    }
    var resolved = undefined;
    if (typeof key == 'function') {
        resolved = key(obj);
    } else if (typeof key == 'string' ) {
        resolved = obj[key];
        if (resolved == null && key.indexOf(".") != -1) {
            resolved = _.deepGet(obj, key);
        }
    }
    return resolved;
}

回答5:

I noticed many of these answers are outdated or contain auxiliary functions not listed in Lodash documentation. The accepted answer includes deprecated function _.contains and should be updated.

So here is my ES6 answer.

Based on Lodash v4.17.4

_.mixin( {
    filterByValues: ( c, k, v ) => _.filter(
        c, o => _.indexOf( v, o[ k ] ) !== -1
    )
} );

And invoked as such:

_.filterByValues(
    [
        {
            name: 'StackOverflow'
        },
        {
            name: 'ServerFault'
        },
        {
            name: 'AskDifferent'
        }
    ],
    'name',
    [ 'StackOverflow', 'ServerFault' ]
);

// => [ { name: 'StackOverflow' }, { name: 'ServerFault' } ]

回答6:

These answers didn't work for me, because I wanted to filter on a non-unique value. If you change keyBy to groupBy you can get by.

_(collections)
  .groupBy(attribute)
  .pick(possibleValues)
  .values()
  .flatten()
  .value();

My initial use was to drop things, so I switched out pick with omit.

Thanks Adam Boduch for the starting point.

回答7:

This worked great for me:

let output = _.filter(collections, (v) => _.includes(ids, v.id));