Angular5 1-n circulation duct, to achieve similar vue as v-for = "i of 10"

import { PipeTransform, Pipe } from "@angular/core";
import { isFunction } from "ionic-angular/util/util";
const MAX_SAFE_INTEGER = 9007199254740991;
const MAX_ARRAY_LENGTH = 4294967295;
@Pipe({
  name: "times",
  pure: true
})

export class TimesPipe implements PipeTransform {
  transform(value: any, args?: (index: number) => void): any {
    if(!value){
        value=0;
    }
    value=Number(value);
    if (value < 1 || value > MAX_SAFE_INTEGER) {
      return [];
    }
    let index = MAX_ARRAY_LENGTH;
    const length = Math.min(value, MAX_ARRAY_LENGTH);
    if (!isFunction(args)) {
      args = () => {};
    }
    value -= MAX_ARRAY_LENGTH;
    const result = baseTimes(length, args);
    while (++index < value) {
      args(index);
    }
    return result;
  }
}
function baseTimes(n, fn) {
  let index = -1;
  const result = Array(n);
  while (++index < n) {
    result[index] = fn(index);
  }
  return result;
}

 

Published 42 original articles · won praise 4 · Views 4612

Guess you like

Origin blog.csdn.net/lucasxt/article/details/103085082