javascript - Angular : total of all country in each row when select option "ALL"

Question

我有一个表，其中有 2 个差异。每个国家/地区的值(按月)，当我在选择框中选择每个国家/地区时，它工作正常，但是当我选择“全部”选项时，我需要所有国家/地区(按月)包含的所有值的总和。即{{month.A}} 应为 46(JAN)、56(FEB)，{{month.S}} 应为 38(JAN) 和 28(FEB)。

另外，请指导我，因为所有选项在选择框中都没有很好地显示。 fiddle 是https://jsfiddle.net/tffv2owp/

$scope.months =
    [{ "country": "UK", "mon": "JAN", "A": "14", "S": "2"},
     { "country": "AUSTRIA", "mon": "JAN", "A": "24", "S": "12"},
     { "country": "ITALY", "mon": "JAN",  "A": "5", "S": "21"},
     { "country": "SWIZ", "mon": "JAN",  "A": "3", "S": "3"},
     { "country": "UK", "mon": "FEB", "A": "4", "S": "12"},
     { "country": "AUSTRIA", "mon": "FEB", "A": "24", "S": "12"},
     { "country": "ITALY", "mon": "FEB",  "A": "15", "S": "1"},
     { "country": "SWIZ", "mon": "FEB",  "A": "13", "S": "3"}
    ];

Answer 1

维护过滤函数中值的聚合。如果提供“ALL”，则重新计算聚合(或者如果这些聚合可能保持不变，则计算一次并缓存)。 Here是每次应用过滤器时重新计算的示例。以及重要的补充:

// Add an "ALL" value to countries
$scope.countries = ["ALL", "UK", "AUSTRIA", "ITALY", "SWIZ"];

// ...

app.filter('filterMultiple',['$filter',function ($filter) {
    // maintain singleton aggregate to prevent max $digest cycle
    // each month would go here -- start each value (e.g. A, S) at 0
    var aggregateItems = [
        {mon: 'JAN', A: 0, S: 0},
        {mon: 'FEB', A: 0, S: 0}
    ];
    return function (items, keyObj) {
        var filterObj = {
            /* filterObj remains same */
        };

        // check for 'ALL' Selection
        if (keyObj && keyObj.country === 'ALL') {
            var aggs = {};
            // 0 out aggregate values to recalculate
            angular.forEach(aggregateItems, function (obj) {
                obj.A = 0;
                obj.S = 0;

                // reverse lookup by month
                aggs[obj.mon] = obj;
            });

            // aggregate months / items
            angular.forEach(items, function (obj) {
                aggs[obj.mon].A = aggs[obj.mon].A + (parseInt(obj.A, 10) || 0);
                aggs[obj.mon].S = aggs[obj.mon].S + (parseInt(obj.S, 10) || 0);
            });

            // totals calculated
            return aggregateItems;
    } else if(keyObj){
        // Your original logic
    }

    return filterObj.filteredData;
});