Javascript多条件数组过滤器

Question

我需要帮助来整理基于多个条件的数组搜索。此外，所有条件都是有条件的，这意味着我可能需要也可能不需要过滤这些条件。我有什么：

要过滤的对象数组：

var data = [{
    "_id" : ObjectId("583f6e6d14c8042dd7c979e6"),
    "transid" : 1,
    "acct" : "acct1",
    "transdate" : ISODate("2012-01-31T05:00:00.000Z"),
    "category" : "category1",
    "amount" : 103
},
{
    "_id" : ObjectId("583f6e6d14c8042dd7c2132t6"),
    "transid" : 2,
    "acct" : "acct2",
    "transdate" : ISODate("2012-01-31T05:00:00.000Z"),
    "category" : "category2",
    "amount" : 103
},
{
    "_id" : ObjectId("583f6e6d14c8042dd7c2132t6"),
    "transid" : 3,
    "acct" : "acct2",
    "transdate" : ISODate("2016-07-31T05:00:00.000Z"),
    "category" : "category1",
    "amount" : 103
},
{
    "_id" : ObjectId("583f6e6d14c8042dd7c2132t6"),
    "transid" : 4,
    "acct" : "acct2",
    "transdate" : ISODate("2012-01-31T05:00:00.000Z"),
    "category" : "category2",
    "amount" : 103
},
{
    "_id" : ObjectId("583f6e6d14c8042dd7c2132t6"),
    "transid" : 5,
    "acct" : "acct2",
    "transdate" : ISODate("2012-01-31T05:00:00.000Z"),
    "category" : "category3",
    "amount" : 103
},
{
    "_id" : ObjectId("583f6e6d14c8042dd7c152g2"),
    "transid" : 6,
    "acct" : "acct3",
    "transdate" : ISODate("2016-10-31T05:00:00.000Z"),
    "category" : "category3",
    "amount" : 103
}]

我正在根据另一个混合元素数组过滤上述对象数组。这些元素代表以下搜索字段：

• “searchstring”：在数据数组中的所有字段中搜索任何 匹配的文本序列

• 具有代表帐户类型和真假的键值的对象 用于指示是否应用于过滤的值

• 过滤transdate的开始日期

• 过滤transdate的结束日期

• 要过滤类别的类别名称

具有搜索条件的数组看起来像这样（但如果某些字段不是必需的，它们将被设置为未定义或只是一个空字符串或数组）：

var filtercondition = {
    "p",
    {acct1:true,acct2:false,acct3:true...}
    "2016-06-01",
    "2016-11-30",
    "category3"
}

实现这一目标的最佳方法是什么？我设计的是对过滤器数组中的每个元素进行单独搜索，但这似乎不是最优的并且非常乏味。我愿意重新设计我的设置...

Answer 1

// You wrote that it's an array, so changed the braces 
var filtercondition = ["p",
{acct1:true,acct2:false,acct3:true...}
"2016-06-01",
"2016-11-30",
"category3"
];

var filtered = data.filter(o => {
    if(filtercondition[0] && !o.category.includes(filtercondition[o])) { // checking just the category, but you can check if any of more fields contains the conditions 
        return false;
    }
    if(filtercondition[1]) {
        for(var key in filtercondition[1]) {
        if(filtercondition[1][key] === true && o.acct != key) {
            return false;
        }
        }
    }
    if(filtercondition[2] && o.transdate < filtercondition[2]) {
        return false;
    }
    if(filtercondition[3] && o.transdate > filtercondition[3]) {
        return false;
    }
    if(filtercondition[4] && o.category !== filtercondition[4]) {
        return false;
    }

    return true;
});

两个注意事项： - 更改了filtercondition 的大括号，使其成为一个数组，但是我建议改用一个对象。 - 这个{acct1:true,acct2:false,acct3:true...} 示例对我来说没有意义，因为它表明acct 字段应该同时是acct1 和acct3。

Answer 2

创建一个函数数组，每个函数代表一个条件。

这是一些演示该方法的示例代码...

 var conditions = [];

 // Dynamically build the list of conditions
 if(startDateFilter) {
    conditions.push(function(item) { 
       return item.transdate >= startDateFilter.startDate;
    });
 };

 if(categoryFilter) {
     conditions.push(function(item) {
         return item.cateogry === categoryFilter.category;
     });
 };
 // etc etc

一旦有了条件数组，就可以使用Array.prototype.every 对项目运行每个条件。

 var itemsMatchingCondition = data.filter(function(d) {
     return conditions.every(function(c) {
         return c(d);
     });
 });

或者，使用更紧凑的箭头函数：

const itemsMatchingCondition = data.filter(d => conditions.every(c => c(d));

Answer 3

首先，您需要为数组使用方括号而不是花括号：

var filtercondition = [
    "p",
    {acct1:true,acct2:false,acct3:true...},
    "2016-06-01",
    "2016-11-30",
    "category3"
];

再一次，我不认为数组是最好的数据类型。试试这样的对象：

var filtercondition = {
    query: "p",
    accounts: {acct1:true,acct2:false,acct3:true...},
    date1: "2016-06-01",
    date2: "2016-11-30",
    category: "category3"
};

然后，尝试使用 Array.prototype.filter：

var filtered = data.filter(function(obj) {
    for (var key in filtercondition) {
        // if condition not met return false
    }
    return true;
});

Answer 4

我会使用一堆小的粒度函数并组合它们。

//only some utilities, from the top of my mind
var identity = v => v;

//string-related
var string = v => v == null? "": String(v);
var startsWith = needle => haystack => string(haystack).startsWith(needle);
var endsWith = needle => haystack => string(haystack).endsWith(needle);
var contains = needle => haystack => string(haystack).contains(needle);

//do sth with an object
var prop = key => obj => obj != null && prop in obj? obj[prop]: undefined;
var someProp = fn => obj => obj != null && Object.keys(obj).some(k => fn(k) );
var someValue = fn => obj => obj != null && Object.keys(obj).some(k => fn(obj[k]) );

//logic
var eq = b => a => a === b;
var not = fn => function(){ return !fn.apply(this, arguments) };
var and = (...funcs) => funcs.reduce((a, b) => function(){
        return a.apply(this, arguments) && b.apply(this, arguments);
    });

var or = (...funcs) => funcs.reduce((a, b) => function(){
        return a.apply(this, arguments) || b.apply(this, arguments);
    });

//composition
var compose = (...funcs) => funcs.reduce((a, b) => v => return a(b(v)));
var chain = (...funcs) => funcs.reduceRight((a, b) => v => return a(b(v)));

//and whatever else you want/need
//but stay granular, don't put too much logic into a single function

和一个示例组合：

var filterFn = and(
    //some value contains "p"
    someValue(contains("p")),

    //and
    chain(
        //property "foo"
        prop("foo"), 
        or(
            //either contains "asdf"
            contains("asdf"),

            //or startsWith "123"
            startsWith("123")
        )
    ),
)

由于我不知道您是如何构建过滤条件的，因此我无法准确告诉您如何将它们解析成这样的组合，但您可以像这样组合它们：

//start with something basic, so we don't ever have to check wether filterFn is null
var filterFn = identity;

//and extend/compose it depending on some conditions
if(/*hasQuery*/){
    filterFn = and(
        // previous filterFn(obj) && some value on obj contains `query`
        filterFn,
        someValue(contains(query)))
    )
}

if(/*condition*/){
    //extend filterFn
    filterFn = or(
        // (obj.foo === null) || previous filterFn(obj)
        chain(prop("foo"), eq(null)),
        filterFn
    );
}

等等

Answer 5

首先，几点：

• 如果您要在浏览器中使用 data 对象，则它是无效的。可能数据来自MongoDB，对吧？您的后端（数据源）应该有一种方法可以对其进行正确编码并删除 ObjectID 和 ISODate 引用。

• 您的 filtercondition 不是有效的 JavaScript 对象/JSON。查看我的示例。

因此，您可以使用Array#filter 方法过滤您的数据数组。

类似的东西：

let data = [{
    "_id" : "583f6e6d14c8042dd7c979e6",
    "transid" : 1,
    "acct" : "acct1",
    "transdate" : "2012-01-31T05:00:00.000Z",
    "category" : "category1",
    "amount" : 103
},
{
    "_id" : "583f6e6d14c8042dd7c2132t6",
    "transid" : 2,
    "acct" : "acct2",
    "transdate" : "2012-01-31T05:00:00.000Z",
    "category" : "category2",
    "amount" : 103
},
{
    "_id" : "583f6e6d14c8042dd7c2132t6",
    "transid" : 5,
    "acct" : "acct2",
    "transdate" : "2012-01-31T05:00:00.000Z",
    "category" : "category3",
    "amount" : 103
}];


let filterToApply = {
    acct: {
        acct1: true,
        acct2: false,
        acct3: true
    },
    initialDate: "2016-06-01",
    finalDate: "2016-11-30",
    category: "category3"
}


let filterData = (array, filter) => {

    return array.filter( (item) => {

        /* here, you iterate each item and compare with your filter,
           if the item pass, you must return true. Otherwise, false */


        /* e.g.: category check (if present only) */
        if (filter.category && filter.category !== item.category) 
            return false;
        }

        /* add other criterias check... */ 

        return true;
});

}

let dataFiltered = filterData(data, filterToApply);
console.log(dataFiltered);