如何设置动态输入的最大值?

时间:2019-02-21 19:55:05

标签: javascript vue.js vee-validate

我有带有动态输入的Vue形式。

1号用户以表格形式注册股份总数
2号他开始通过向他的股东部分增加总金额来开始向股东发放此总额
他第三次提交表格。
我的任务是避免发行过多。

我无法弄清楚如何避免向股东发行股份的数量超过总数/

Ex:
totalSharesAmount = 100
shareholder[0] - shares_amount = 50 
shareholder[1] - shares_amount = 20 //70 total
shareholder[2] - shares_amount = 30 //100 total. can't be more than 100

我的数据:

data() {
return {
    totatSharesAmount: 100
    shareholders: [{share_amount: '', share_price: ''}]
    }
}

我的validate方法(已计算),在这里我需要帮助:

sharesToFounders() {
    return {
      required: true,
      max_value: this.totalSharesAmount - this.shareholder['shares_amount'] //need help here
   }
}

2 个答案:

答案 0 :(得分:1)

您需要计算才能跟踪剩余点。当剩余点时,需要一个函数将元素添加到数组中。您需要连接watcher才能调用该函数。下面的代码片段可以做到这一点。

new Vue({
  el: '#app',
  data() {
    return {
      totalPoints: 100,
      foundersPoints: []
    };
  },
  methods: {
    addPoint() {
      this.foundersPoints.push({
        points_amount: null,
        point_price: null
      });
    }
  },
  watch: {
    remainingPoints: {
      handler(v) {
        if (v > 0 && this.pointValues.every((v) => v > 0)) {
          this.addPoint();
        }
        if (v <= 0 || isNaN(v)) {
          // Remove any zeros, probably just the last entry
          this.foundersPoints = this.foundersPoints.filter((o) => o.points_amount > 0);
        }
      },
      immediate: true
    }
  },
  computed: {
    pointValues() {
      return this.foundersPoints.map((o) => o.points_amount);
    },
    remainingPoints() {
      const used = this.pointValues.reduce((a, b) => a + b, 0);

      return this.totalPoints - used;
    }
  }
});
:invalid {
  border: solid red 2px;
}
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.17/vue.js"></script>
<div id="app">
  <div v-for="p in foundersPoints">
    <input v-model.number="p.points_amount" type="number" min="1" :max="p.points_amount + remainingPoints">
  </div>
  <div>Remaining shares: {{remainingPoints}}</div>
</div>

答案 1 :(得分:1)

一种解决方法:跟踪当前总数,并在输入时使用验证器方法允许用户更改或阻止更改。

标记:

<div id="app">
  <div class="row"><span>Total:</span><input type="number" v-model="totalPoints"></div>
  <div v-for="(item, index) in foundersPoints" class="row">
    <input type="number" v-on:input="updateValue(index)" v-model="foundersPoints[index].points_amount"><span v-if="foundersPoints[index].alert" class="alert">{{foundersPoints[index].alert}} <button v-on:click="dismissAlert(index)">OK</button></span>
  </div>
</div>

Validator方法:

updateValue(idx) {
    let value;
    if (this.tempSum > this.totalPoints) {
    const overage = this.totalPoints - this.tempSum;
    value = Number(this.foundersPoints[idx].points_amount) + overage;
  } else {
    value = Number(this.foundersPoints[idx].points_amount);
  }
  this.foundersPoints[idx].points_amount = value;
},

用于跟踪的当前总计(计算属性):

computed: {
  tempSum() {
    const pointsAmounts = this.foundersPoints.map(item => Number(item.points_amount));
    return pointsAmounts.reduce((acc, t) => acc + Number(t), 0);
  }
},

在这个小提琴中实际操作:https://jsfiddle.net/ebbishop/vu508Lgc/

这不适用于用户减少允许的总积分的情况。 (用户的总数为60,然后将三个点的值分别设置为20。如果用户将总数更改为40,那么加起来为60的输入将如何处理?)