如何使用 Angular Pipe 减少数组中对象的元素

如何解决如何使用 Angular Pipe 减少数组中对象的元素

我有这样的列表：

async createCsv(result) {
    const arrData = result.data
    const aliases = result.aliases
    
    let csvContent = [
        Object.keys(arrData[0]).map(item => aliases[item]).join(";"),...arrData.map(item => Object.values(item).join(";"))
    ]
    .join("\n")
    .replace(/(^\[)|(\]$)/gm,"");
    
    const data = new Blob([csvContent],{
        type: "text/csv;charset=windows-1251;"
    });
    
    const link = document.createElement("a");
    link.setAttribute("href",URL.createObjectURL(data));
    link.setAttribute("download",(new Date).toLocaleString() + ".csv");
    link.style.visibility = 'hidden';
    document.body.appendChild(link);
    link.click();
    document.body.removeChild(link);
}

现在，我想用reduce方法添加中心的所有值，其中包括：'APP'和'AD'，并将标签更改为'APP'，所以在这个列表示例中，我创建了管道必须返回： APP：209（总计）和LFFFAD：78

管道：

[{"center":"LFEEAPP","cause":"S ","total":66},{"center":"LFFFAD","cause":"S","total":78},{"center":"LFMMAPP","cause":"C","total":143},"cause":"T","total":0}]

如何将“AD”字符串添加到过滤器中以获取： APP：287（APP：209 + LFFFAD：78） 感谢您的帮助

解决方法

export class MergeCentresAppPipe implements PipeTransform {

  transform(listCount: ListCount[]): ListCount[] {
    const totalCenterApp = listCount
      .filter(count => count.center.includes('APP') || count.center.includes('AD')))
      .map(count => count.total)
      .reduce((sum,current) => sum + current,0);

    const centerApp: ListCount = {
      center: 'APP',cause: '',total: totalTimeCenterApp,};

    const centerMerged = listCount.filter(count => !count.center.includes('APP') && !count.center.includes('AD'));
    centreMerged.push(centerApp);

    return centerMerged;
  }
}