[英]In Vue js, how can i assign unique id that doesn't reset when page gets reloaded
我正在做一个小项目来进入 Vue js。 它应该是一个习惯追踪器。 我目前有一个错误,如果你重新加载页面并添加新的习惯,我应该改变背景的功能无法正常工作。
这里显示了错误,这是我的数组的外观:
0
:
{id: 0, title: "1", ready: false}
1
:
{id: 1, title: "123", ready: false}
2
:
{id: 2, title: "123", ready: false}
3
:
{id: 0, title: "123", ready: true}
我明白为什么它不起作用,因为我正在使用一个计数器来分配 id,重新加载时它会重置为 0。
<div class="q-pa-md" v-for="(habit, index) in habits" :key="habit.id">
<q-card class="my-card" :id="habit.id" ref="card">
<q-card-section>
<q-checkbox
id="checkbox"
v-model="habit.ready"
@click="changeToTransparent(habit)"
>
</q-checkbox>
{{ habit.title }}
<q-btn-dropdown flat class="more" icon="more_horiz">
<q-list>
<q-item clickable v-close-popup @click="deletehabit(index)">
<q-item-section>
<q-item-label>Delete</q-item-label>
</q-item-section>
</q-item>
<q-item clickable v-close-popup @click="edithabitbutton(index)">
<q-item-section>
<q-item-label>Edit</q-item-label>
</q-item-section>
</q-item>
</q-list>
</q-btn-dropdown>
</q-card-section>
</q-card>
<div>
let counter = 0;
const habits = ref([]);
const addHabit = () => {
habits.value.push({ id: counter++, title: habittitle.value, ready: false });
savetolocalstorage();
habittitle.value = "";
};
const changeToTransparent = (habit) => {
if(document.getElementById(habit.id) != null) {
if (habit.ready) {
document.getElementById(habit.id).style.backgroundColor =
"rgba(170,193,200,0.25)";
savetolocalstorage();
} else {
document.getElementById(habit.id).style.backgroundColor = "";
savetolocalstorage();
}
}
}
关于如何解决这个问题的任何想法?
您需要加载 localStorage 并将长度设置为计数器值。 我在这里做了一个工作示例。 我还改进了你的代码,使其更符合 Vue 的概念。 正如@Rahul Purohit 指出的那样,保存时需要对结果进行JSON.stringify
,加载时需要对结果进行JSON.parse
。
<template>
<q-input label="Title" v-model="habitTitle" />
<q-btn label="Add habit" @click="addHabit" />
<div class="q-pa-md" v-for="(habit, index) in habits" :key="habit.id">
<q-card
class="my-card"
:id="habit.id"
:ref="(el) => (cardRefs[habit.id] = el)"
>
<q-card-section>
<q-checkbox
id="checkbox"
v-model="habit.ready"
@click="changeToTransparent(habit)"
>
</q-checkbox>
{{ habit.id }} {{ habit.title }}
<q-btn-dropdown flat class="more" icon="more_horiz">
<q-list>
<q-item clickable v-close-popup @click="deletehabit(index)">
<q-item-section>
<q-item-label>Delete</q-item-label>
</q-item-section>
</q-item>
<q-item clickable v-close-popup @click="edithabitbutton(index)">
<q-item-section>
<q-item-label>Edit</q-item-label>
</q-item-section>
</q-item>
</q-list>
</q-btn-dropdown>
</q-card-section>
</q-card>
</div>
</template>
<script setup>
const { ref, onMounted } = require("vue");
// it can be just a let.
const counter = ref(0);
const habits = ref([]);
const habitTitle = ref("test");
const cardRefs = ref({});
const saveToLocalStorage = () => console.log("saved");
const addHabit = () => {
habits.value.push({
id: counter.value++,
title: habitTitle.value,
ready: false,
});
saveToLocalStorage();
habitTitle.value = "";
};
const changeToTransparent = (habit) => {
if (cardRefs.value[habit.id] != null) {
if (habit.ready) {
cardRefs.value[habit.id].$el.style.backgroundColor =
"rgba(170,193,200,0.25)";
saveToLocalStorage();
} else {
cardRefs.value[habit.id].$el.style.backgroundColor = "";
saveToLocalStorage();
}
}
};
onMounted(() => {
// Load habits from localStorage
// This is just an example
habits.value = [
{
id: 0,
title: "Testing new habit",
ready: true,
},
{
id: 1,
title: "Testing new habit",
ready: false,
},
{
id: 2,
title: "Testing new habit",
ready: false,
},
];
counter.value = habits.value.length;
});
</script>
好的,从给定的上下文来看,我相信您没有使用任何后端,而是将所有条目保存在本地存储中。
如果是这种情况,您必须将数据存储在某个数组中以达到 LS 之类的habits: []
在这里,您可以添加一个生命周期方法,而不是将计数器初始化为 0。
beforeMount() {
counter = JSON.parse(localStorage.getItem("habits")).length
}
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