javascript - 使用lodash转换集合

我有一个查询，可以向我提供Json数据；例如我有以下杰森

{
"salesInvoices":

    [
    {
        "id": "1",
        "salesInvoiceLines":
        [
            {
                "ItemCode": "Apple",
                "UnitCode": "piece",
                "Quantity": "10"
            },
            {
                "ItemCode": "Orange",
                "UnitCode": "box",
                "Quantity": "2"
            }
        ]
    },
    {
        "id": "2",
        "salesInvoiceLines":
        [
            {
                "ItemCode": "Apple",
                "UnitCode": "piece",
                "Quantity": "20"
            },
            {
                "ItemCode": "Orange",
                "UnitCode": "piece",
                "Quantity": "21"
            },
            {
                "ItemCode": "Orange",
                "UnitCode": "box",
                "Quantity": "1"
            }
        ]
    }
    ]

}

我想按项目单位对将数据分组为以下格式：

[
  { item : 'Apple', unit : 'piece', totalQuantity : 30 },
  { item : 'Orange', unit : 'piece', totalQuantity : 21 },
  { item : 'Orange', unit : 'box', totalQuantity : 3 }
]

我用lodash库累了下面的代码，但是不起作用

   var sumQuantity = function(total, item){
        return total + item.Quantity
    }

    var transformList = function(line){
        return _.map(line.SalesInvoiceLines, function(invoice){
            return _.map(invoice, function(line){
                return {
                    item: line.ItemCode,
                    unit: line.UnitCode,
                    totalQuantity: _.reduce(line.Quantity, sumQuantity, 0)
                }
            })
        });
    };

    var groupedList = _.groupBy(data.d.results, function(line) {
        return line.ItemCode + line.UnitCode;
    });

    var list = _.chain(groupedList)
    .map(transformList)
    .flatten()
    .value();

如何获得上述结果？

最佳答案

// Input
var data = {
    "salesInvoices": [{
        "id": "1",
        "salesInvoiceLines": [{
            "ItemCode": "Apple",
            "UnitCode": "piece",
            "Quantity": "10"
        }, {
            "ItemCode": "Orange",
            "UnitCode": "box",
            "Quantity": "2"
        }]
    }, {
        "id": "2",
        "salesInvoiceLines": [{
            "ItemCode": "Apple",
            "UnitCode": "piece",
            "Quantity": "20"
        }, {
            "ItemCode": "Orange",
            "UnitCode": "piece",
            "Quantity": "21"
        }, {
            "ItemCode": "Orange",
            "UnitCode": "box",
            "Quantity": "1"
        }]
    }]

}

//Output
/*
[
  { item : 'Apple', unit : 'piece', totalQuantity : 30 },
  { item : 'Orange', unit : 'piece', totalQuantity : 21 },
  { item : 'Orange', unit : 'box', totalQuantity : 3 }
]
*/

// Code
_.chain(_.flatten(_.map(data.salesInvoices, 'salesInvoiceLines')))
    .reduce(function(output, curr) {
        output[curr.ItemCode + '_' + curr.UnitCode] = output[curr.ItemCode + '_' + curr.UnitCode] ? output[curr.ItemCode + '_' + curr.UnitCode] + parseInt(curr.Quantity) : parseInt(curr.Quantity);
        return output;
    }, {})
    .reduce(function(result, value, key) {
        result.push({
            item: key.split('_')[0],
            unit: key.split('_')[1],
            totalQuantity: value
        });
        return result;
    }, []).value();

关于javascript - 使用lodash转换集合，我们在Stack Overflow上找到一个类似的问题：https://stackoverflow.com/questions/34837919/