Problems with chart.js redrawing or not redrawing graphs - vue.js

Question

I am Japanese. Therefore, my sentences may be strange. Please keep that in mind.
I am writing code using vue.js, vuex, vue-chart.js and vue-chart.js to display the population of each prefecture of Japan when checked.I’m code is written to redraw the graph when the input element for each prefecture is checked.However, it does not redraw when checked.Also, it may redraw after half of the check.I believe this phenomenon can be confirmed from the following URL.
https://yumemi-coding.web.app/
※There are no errors.
Here's a question: what causes the graphs to redraw or not? Also, how can I code to remedy this?
What I have done to counteract the cause is as follows
I went to the official website and used the rendering process as a reference.
　URL：https://vue-chartjs.org/migration-guides/#new-reactivity-system
　=> The way we did it was right.
We thought there was a problem with VueX and coded in a way that did not use it. => There was nothing wrong with vuex.
TopFroont.vue
<template>
<div class="Bar_area">
<Bar :options="chartOptions" :data="chartData" class="Bar_item" />
</div>
</template>
<script>
import { Bar } from "vue-chartjs"
import { Chart as ChartJS, registerables } from "chart.js"
ChartJS.register(...registerables)
export default {
name: "BarChart",
components: { Bar },
data() {
return {
chartOptions: {
responsive: true,
},
}
},
computed: {
chartData() {
return {
labels: this.$store.state.years,
datasets: this.$store.state.prefectures,
}
},
},
}
</script>
NaviBar.vue
<template>
<div class="navApp">
<ul>
<li v-for="(pref, index) in prefData" :key="index" class="pref_itemBox">
<label>
<input type="checkbox" #change="checkItem(pref)" />
<span class="pref_text">{{ pref.prefName }}</span>
</label>
</li>
</ul>
</div>
</template>
<script>
import resasInfo from "#/library/resas.js"
import axios from "axios"
export default {
data() {
return {
resasInfo: resasInfo,
url: resasInfo.url_prefectures,
api: resasInfo.api,
prefData: [],
prefectures: [],
}
},
async created() {
const request_Header = {
headers: { "X-API-KEY": this.api.key },
}
await axios.get(this.url, request_Header).then((res) => {
const value = res.data.result
this.prefData.push(...value)
})
},
methods: {
checkItem(pref) {
// チェックされてる都道府県のみを配列に入れる
const isExistencePref = this.prefectures.indexOf(pref)
isExistencePref === -1
? this.prefectures.push(pref)
: this.prefectures.splice(isExistencePref, 1)
this.$store.dispatch("getPrefectures", this.prefectures)
},
},
}
</script>
vuex => store/index.js
import axios from "axios"
import { createStore } from "vuex"
import createPersistedState from "vuex-persistedstate"
export default createStore({
state: {
prefectures: [],
years: [],
},
mutations: {
getPrefs(state, payload) {
state.prefectures = payload
},
getYears(state, payload) {
state.years = payload
},
},
actions: {
getPrefectures({ commit }, payload) {
// payload => 各都道府県のprefCode + prefName
const allPrefecture_Data = []
const result = payload.map(async (el) => {
const prefCode_data = el.prefCode
axios
.get(
`https://opendata.resas-portal.go.jp/api/v1/population/composition/perYear?prefCode=${prefCode_data}&cityCode=-`,
{
headers: {
"X-API-KEY": "5RDiLdZKag8c3NXpEMb1FcPQEIY3GVwgQwbLqFIx",
},
}
)
.then((res) => {
const value = res.data.result.data[0].data
const TotalPopulation_Year = []
const TotalPopulation_Data = []
// 都道府県の総人口データと年データを各配列に入れ込む
value.forEach((element) => {
TotalPopulation_Data.push(element.value)
TotalPopulation_Year.push(element.year)
})
// rgbaを自動生成する関数 => backgroundColor
const generateRGBA = () => {
const r = Math.floor(Math.random() * 256)
const g = Math.floor(Math.random() * 256)
const b = Math.floor(Math.random() * 256)
const a = 0.8
return `rgba(${r}, ${g}, ${b}, ${a})`
}
// chart.jsに入れ込むデータ
const prefData = {
label: el.prefName,
data: TotalPopulation_Data,
backgroundColor: generateRGBA(),
}
allPrefecture_Data.push(prefData)
commit("getPrefs", allPrefecture_Data)
commit("getYears", TotalPopulation_Year)
})
.catch((err) => {
console.log(err)
})
})
return result
},
},
plugins: [createPersistedState()],
getters: {},
modules: {},
})