Question

我正在尝试使用管道转换数据。管道在html中运行良好，但在组件中使用时不想工作。我收到以下错误： '类型'Observable'的参数不能分配给'any []'类型的参数。 'Observable'类型中缺少属性'includes'。'

Component.ts：

this.locationChangeForUserObservable = fucareDatabaseService.getLocationChangesForUser('user1' + '/locationChange');
this.list = new WeekFilterPipe().transform(this.locationChangeForUserObservable, 'datum', this.mondayInMS);
this.list = new CalculateWeekPipe().transform(this.locationChangeForUserObservable, this.mondayInMS);

我的烟斗：

@Pipe({
  name: 'weekFilter'
})
@Injectable()
export class WeekFilterPipe implements PipeTransform {
  transform(items: any[], field: string, value: string): any[] {
    if (!items) {
      return [];
    }

    if (!field || !value) {
      return items;
    }

    var monday = moment(value);
    var tuesday = moment(monday).add('24', 'hours');
    var wednesday = moment(monday).add('48', 'hours');
    var thursday = moment(monday).add('72', 'hours');
    var friday = moment(monday).add('96', 'hours');
    var saturday = moment(monday).add('120', 'hours');
    var sunday = moment(monday).add('144', 'hours');
    monday = monday.format('DD-MM-YYYY');
    tuesday = tuesday.format('DD-MM-YYYY');
    wednesday = wednesday.format('DD-MM-YYYY');
    thursday = thursday.format('DD-MM-YYYY');
    friday = friday.format('DD-MM-YYYY');
    saturday = saturday.format('DD-MM-YYYY');
    sunday = sunday.format('DD-MM-YYYY');
    return items.filter(item => {
      if (item[field].includes(monday) || item[field].includes(tuesday) ||
        item[field].includes(wednesday) || item[field].includes(thursday)
        || item[field].includes(friday) || item[field].includes(saturday) || item[field].includes(sunday))  {
        return true;
      }
    });
  }


@Pipe({
  name: 'calculateWeekPipe'
})
@Injectable()
export class CalculateWeekPipe implements PipeTransform {


  transformDate(datum) {
    var temp = datum.split(' ')[0];
    var temp = temp.split('-');

    return temp.reverse().join('-') + ' ' + datum.split(' ')[1];
  }
  getDay(item) {

    var datum = item.datum;
    if (typeof datum === 'undefined') {
      console.log('damn');
    }
   ...

非常感谢任何帮助！

提前致谢。

Answer 1

您无法将Observable转换为Array，因为它是异步的，但您可以订阅observable并将发出的值传递给管道函数：

this.locationChangeForUserObservable.subscribe(locationChanges => {
    this.list = new CalculateWeekPipe().transform(locationChanges , this.mondayInMS);
});

例如。

当然，如果这个observable正好返回你需要传递给管道函数的数组。否则，您可能需要进行一些转换（map，toArray可能，取决于实际发出的值）

可以观察<any []>到Array []

1 个答案: