Undescore mixins : whereDeep

underscore_mixins.js

// inspired from _.matches
function deepMatch (attrs) {
    return function (obj) {
        var attrVal, objVal;
        if (obj === attrs) return true; //avoid comparing an object to itself.
        for (var key in attrs) {
            attrVal = attrs[key];
            objVal = obj[key];
            if (_.isObject(attrVal) && _.isObject(objVal)) {
                if (!deepMatch(attrVal)(objVal)) {
                    return false;
                }
            }
            else if (attrVal !== objVal) {
                return false;
            }
        }
        return true;
    };
}


_.extend(Backbone.Collection.prototype, {
    // inspired from Collection.where
    whereDeep: function(attrs) {
        if (_.isEmpty(attrs)) {
            return [];
        }
        return this.filter(function(model) {
            return deepMatch(attrs)(model.attributes);
        });
    }
});

_.mixin({
    // inspired from _.where
    whereDeep: function(obj, attrs) {
        return _.filter(obj, deepMatch(attrs));
    }

});