object is not extensible 错误在vuejs

Question

我想用名为 colspan 的新字段更新促销对象。但是我运气不好，得到

错误：

未捕获（承诺）TypeError：无法添加属性 colspan，对象不可扩展在评估（评估在（http://localhost:8080/app.js:3160:1），：71:32）在 Array.forEach（本地）在评估（评估在（http://localhost:8080/app.js:3160:1），：66:35）在 Array.forEach（本地）在评估（评估在（http://localhost:8080/app.js:3160:1），：64:47）在 Array.forEach（本地）在评估（评估在（http://localhost:8080/app.js:3160:1），：62:23）在承诺 () 在 F（在（http://localhost:8080/app.js:865:1）评估，：35:28）在 Object.modifyData（在（http://localhost:8080/app.js:3160:1）评估，：48:12）

departmentIds.forEach(departmentId => {
          results[departmentId] = []
          departmentWiseResults[departmentId].forEach((promo, index) => {
            let tmpPromo = promo
            dateRanges.dateRanges.forEach(range => {
              let startedDateWeek = moment(promo.startDate).week()
              let endDateWeek = moment(promo.endDate).week()
              let startedYear = moment(promo.startDate).year()
              let endedYear = moment(promo.endDate).year()
              tmpPromo.colspan = 0
              if (range.startYear === startedYear && range.endYear === endedYear && range.weekNumber <= endDateWeek && range.weekNumber >= startedDateWeek) {
                tmpPromo.colspan++
              }
              departmentWiseResults[departmentId].splice(index, 1, tmpPromo)
              console.log('stareted:', startedDateWeek, endDateWeek, startedYear, endedYear, promo, tmpPromo, departmentWiseResults[departmentId])
            })
            console.log('promo after adding colspna:', promo)
            // if (isInRange(range, promo)) {
            //   console.log('for range', range.startDate, range.endDate)
            //   console.log('for promo', promo.id)
            //   console.log(
            //     'diff is',
            //     findWeekspan(range, dateRanges.dateRanges[dateRanges.dateRanges.length - 1], promo)
            //   )
            // // if (!promo.used) {
            // //   promo.used = true
            // //   results[departmentId]
            // // }
            // }
          })
        })

请帮我解决这个问题。

Answer 1

对象 promo 已通过 Object.preventExtensions (or seal or freeze). That means you cannot add new properties to it. Instead, you can make a new copy of it with new properties. A convenient way to do this is with Object.assign 关闭了可扩展性。

let tmpPromo = Object.assign({colspan: 0}, promo);

这从定义 colspan 的匿名对象开始，将 promo 的属性复制到其中，然后 returns 对象（我们分配给 tmpPromo） .

object is not extensible 错误在vuejs

object is not extensible error in vuejs

javascript

vue.js

vuex