Lodash:按多个属性过滤嵌套对象 [英] Lodash: filter a nested object by multiple properties

问题描述

请考虑以下示例:

var products = {
    "Products": [{
        "Title": "A",
        "Categories": [{
            "Name": "Type",
            "Properties": ["Type 1", "Type 2", "Type 3"]
        }, {
            "Name": "Market",
            "Properties": ["Market 1", "Market 2", "Market 3", "Market 4"]
        }, {
            "Name": "Technology",
            "Properties": ["Tech 1", "Tech 2"]
        }]
    }, {
        "Title": "B",
        "Categories": [{
            "Name": "Type",
            "Properties": ["Type 1", "Type 3"]
        }, {
            "Name": "Market",
            "Properties": "Market 1"
        }, {
            "Name": "Technology",
            "Properties": ["Tech 1", "Tech 3"]
        }]
    }, {
        "Title": "C",
        "Categories": [{
            "Name": "Type",
            "Properties": ["Type 1", "Type 2", "Type 3"]
        }, {
            "Name": "Market",
            "Properties": ["Market 2", "Market 3"]
        }, {
            "Name": "Technology",
            "Properties": ["Tech 2", "Tech 3"]
        }]
    }]
}

我正在尝试按产品属性过滤产品，因此考虑使用数组来跟踪所选过滤器:

I'm trying to filter products by their properties so consider I'm using an array to keep track of my selected filters:

var filters = ['Type 3', 'Tech 1'];

使用这些过滤器，我想退回产品A和产品B.

With these filters I would like to return product A and product B.

我目前有这个:

var flattenedArray = _.chain(products).map('Categories').flatten().value();
var result= _.some(flattenedArray , ['Properties', 'Tech 1']);

但是我对如何组合属性以进行组合搜索感到困惑.

But I'm stuck on how to combine the properties for a combined search.

推荐答案

使用_.filter()迭代产品.对于每个产品，使用_.flatMap()组合属性列表，并使用_.intersection()和_.size()查找类别中存在的过滤器数量.将其与原始过滤器数量进行比较，然后返回比较的响应.

Use _.filter() to iterate the products. For each product combine the list of properties using _.flatMap(), and use _.intersection() and _.size() to find the amount of filters that exist in the categories. Compare that to the original number of filters, and return comparison's response.

var products = {"Products":[{"Title":"A","Categories":[{"Name":"Type","Properties":["Type 1","Type 2","Type 3"]},{"Name":"Market","Properties":["Market 1","Market 2","Market 3","Market 4"]},{"Name":"Technology","Properties":["Tech 1","Tech 2"]}]},{"Title":"B","Categories":[{"Name":"Type","Properties":["Type 1","Type 3"]},{"Name":"Market","Properties":"Market 1"},{"Name":"Technology","Properties":["Tech 1","Tech 3"]}]},{"Title":"C","Categories":[{"Name":"Type","Properties":["Type 1","Type 2","Type 3"]},{"Name":"Market","Properties":["Market 2","Market 3"]},{"Name":"Technology","Properties":["Tech 2","Tech 3"]}]}]};

var filters = ['Type 3', 'Tech 1'];

var result = _.filter(products.Products, function(product) {
  return filters.length === _(product.Categories)
      .flatMap('Properties')
      .intersection(filters)
      .size();
});

console.log(result);

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.2/lodash.min.js"></script>

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