重置子組件的 v-model

Question

在我的父元件中我有類似的東西，

<template>
    <ProductCounter v-model="formData.productCount" label="product count" />
</template>

<script setup>

const initialFormData = {
    productCount: null,
    firstname: '',
    surname: '',
    phone: '',
    email: '',
    postcode: '',
    submittedOnce: false,
    errors: []
}

let formData = reactive({ ...initialFormData });

const clearUI = () => {
    formData = reactive({ ...initialFormData });
    triggerInlineForm.value = false;
}

</script>

我的子元件看起來像這樣，

<template>
    <div class="form__row" @reset-counts="resetCount">
        <div class="counter__row">
            <label>{{ label }}</label>
            <div class="form__counter">
                <button class="form__button--decrease form__button--circle form__button--animate-scale" :disabled="value == 0 || props.disabled" @click.prevent="decreaseCount()">
                    <i>
                        <FontAwesomeIcon :icon="['fal', 'minus']" />
                    </i>
                </button>
                <input type="text" v-model="value" :disabled="props.disabled" @input="updateQty" placeholder="0"/>
                <button class="form__button--increase form__button--circle form__button--animate-scale" :disabled="props.disabled" @click.prevent="increaseCount()">
                    <i>
                        <FontAwesomeIcon :icon="['fal', 'plus']" />
                    </i>
                </button>
            </div>
        </div>
    </div>
</template>

<script setup>
import { FontAwesomeIcon } from '@fortawesome/vue-fontawesome';

const emits = defineEmits(['update:modelValue', 'resetCounts']);

const props = defineProps({
    label: {
        type: String,
        required: true
    },
    modelValue: {
        type: String,
        required: true,
        default: 0
    },
    disabled: {
        type: Boolean,
        required: false
    }
});

const value = ref(props.modelValue);

const updateQty = () => {
    emits('update:modelValue', value.value)
}

const increaseCount = () => {
    value.value++
    emits('update:modelValue', value.value)
}

const decreaseCount = () => {
    value.value--;
    emits('update:modelValue', value.value)
}

</script>

我希望當從父級觸發clearUI並且formData被重置時，ProductCounter的v模型應該反映返回到0，但事實並非如此，我哪裡出錯了？

Answer 1

即時解決方案的連結

請下次在 https://play.vuejs.org/ 上準備最低限度的可重現範例。對於你的問題：

請不要覆寫 Vue 中的響應式變數...

只要改變它們Object.assign(formData,initialFormData)：

也不要取消引用元件屬性：const value = ref(props.modelValue)。這些屬性失去了它們的反應性，因為您只是複製了一個原始值。

建立 v-model 模式的最佳方法是使用計算，您可以直接在模板中操作它。

const value = computed({
  get(){
    return props.modelValue;
  },
  set(val){
    emits('update:modelValue', val);
  }
});

此外，您的 count 屬性應該是數字，而不是字串（您會收到 Vue 警告）：

modelValue: {
        type: Number,
        required: true,
        default: 0
    },

此外，無需更新 input 事件上的 prop，因為您已經在 上使用 v-model >。您還應該將輸入的模型轉換為數字：

<input type="text" v-model.number="value" :disabled="props.disabled" placeholder="0"/>

所以你有： 應用程式視圖

<template>
    <p>
      <ProductCounter v-model="formData.productCount" label="product count" />
    </p>
    <button @click="clearUI">
      Clear
    </button>
    <div>
      {{ JSON.stringify(formData) }}
  </div>
</template>

<script setup>
import ProductCounter from './ProductCounter.vue'
import {reactive} from 'vue'
  
const initialFormData = {
    productCount: 0,
    firstname: '',
    surname: '',
    phone: '',
    email: '',
    postcode: '',
    submittedOnce: false,
    errors: []
}

let formData = reactive({ ...initialFormData });

const clearUI = () => {
    Object.assign(formData, initialFormData);
}

</script>

ProductCounter.vue：

<template>
    <div class="form__row">
        <div class="counter__row">
            <label>{{ label }}</label>
            <div class="form__counter">
                <button :disabled="value == 0 || props.disabled" @click.prevent="value--">
                -
                </button>
                <input type="text" v-model.number="value" :disabled="props.disabled" placeholder="0"/>
                <button :disabled="props.disabled" @click.prevent="value++">
                 +
                </button>
            </div>
        </div>
    </div>
</template>

<script setup>
import {computed} from 'vue';
const emits = defineEmits(['update:modelValue']);

const props = defineProps({
    label: {
        type: String,
        required: true
    },
    modelValue: {
        type: Number,
        required: true,
        default: 0
    },
    disabled: {
        type: Boolean,
        required: false
    }
});

const value = computed({
  get(){
    return props.modelValue;
  },
  set(val){
    emits('update:modelValue', val);
  }
});


</script>