Problem with updating charts (chartjs) in vue - vuejs2

Question

I have difficult situation with updates dynamically data on charts. I created vue component that must render analytics from axios. There are several functions (methods) which parse arrived jsons from several API.
I created draw() - method for render every charts.
draw() {
if (this.mychart) {
this.mychart.destroy();
}
const ctx = document.getElementById('main-chart');
this.mychart = new Chart(ctx,
{
type: 'line',
data: {
labels: this.labels,
datasets: this.datacollection
},
options: {
legend: {
display: true,
position: 'bottom',
},
responsive: true,
scales: {
xAxes: [{
type: "time",
display: true,
scaleLabel: {
display: false,
},
ticks: {
major: {
fontStyle: "bold",
fontColor: "#FF0000"
}
}
}],
yAxes: [
{
id: 'y1',
type: 'linear',
position: 'left',
display: false
},
{
id: 'y2',
type: 'linear',
position: 'right',
display: false
},
{
id: 'y3',
type: 'linear',
position: 'left',
display: false
},
{
id: 'y4',
type: 'linear',
position: 'right',
display: false
},
{
id: 'y5',
type: 'linear',
position: 'left',
display: false
},
{
display: false,
gridLines: {
display: false
},
scaleLabel: {
display: true,
labelString: this.labelY
},
ticks: {
min: 0, // it is for ignoring negative step.
beginAtZero: true,
stepSize: 100
}
}]
}
}
});
},
All operations for calculating (parsing) data I do in mounted hook.
Also added in mounted hook nextTick() for delay render charts before data finish parsing.
async mounted() {
await this.loadIncomings(this.clubsId),
await this.loadAvgIncomings(this.clubsId),
await this.loadAvgPayments(this.clubsId),
await this.loadAvgSchedule(this.clubsId),
await this.loadTrainings(this.clubsId)
this.$nextTick(() => {
this.draw()
})
},
Now if internet connection is fast - charts render at one time. If you refresh page - you must waiting approximately 5-20 seconds for parsing data, and after this - appear graphs.
But, if I have bad connection, some axios requests finish with errors, and appear not all charts. And also I must waiting longer for parsing.
Finally, I have situation, that when I refresh page - several seconds page is empty. If connection is bad- not all charts render.
After this I have several questions:
1)How I could start render some finished data by chartjs in first seconds?
I mean not waiting when all data will come and calculated. I would like , that my charts render step by step. I want see y-axis and x-axis after I click refresh window.
Now I am using nextTick() but it is like 2nd step, where 1st step - is parsing data (may be I don't correctly understand)
I found some answers on similar question with render dynamic data, and people offered use chart.update(). But I can't get it. Where I must input this? If you look at my component, I have special method - draw(). If input in final string in my method with parsing data like : this.draw.mychart.update() or this.mychart.update() - I receive error in browser.
For example this function:
async loadIncomings(clubsId) {
try {
for (let clubId in clubsId) {
clubId = clubsId[clubId]
let dateFrom = this.dateFrom
let dateTo = this.dateTo
let groupBy = 'month'
let potential = true
let definitely = true
await this.$store.dispatch('loadIncomings', { clubId, dateFrom, dateTo, groupBy, potential, definitely }) // here I am waiting data from store (in store I use axios)
this.draftData = this.$store.state.incomings
if (this.labels.length === 0) {
this.getDates()
}
this.flagStartDate = true
await this.getIncomings(clubId)
this.flagStartDate = false
}
this.getIncomingsTotal()
this.draw.mychart.update() // here I am trying to refresh charts like advice from forums
} catch (e) {
console.error(e)
}
},
As you can see, this.getIncomingsTotal() - is last method for parsing data. After him, I am trying to update chart. But it's doesn't work.
Analytics-test.vue?b2a7:177 TypeError: Cannot read properties of undefined (reading 'update')
at VueComponent.loadIncomings (Analytics-test.vue?b2a7:175:1)
at async VueComponent.mounted (Analytics-test.vue?b2a7:498:1)
2)Also I use vue2-datepicker. I want set range dateFrom/dateTo. But when I choose date - charts doesn't change.
I have watch() , where I can monitoring dates dateFrom() and dateTo(). And also I am trying to rechart graphs with new dates - but nothing changes.
watch: {
dateFrom() {
console.log('dateFrom changed to', this.dateFrom)
this.draw()
},
dateTo() {
console.log('dateTo changed to', this.dateTo)
this.draw()
}
},
Under I show you my component:
<template>
<div class="container">
<h3>Прибыль/посещаемость</h3>
<date-picker v-model="dateFrom" valueType="date"></date-picker>
<date-picker v-model="dateTo" valueType="date"></date-picker>
<canvas id="main-chart"></canvas>
</div>
</template>
<script>
import Chart from 'chart.js';
import DatePicker from 'vue2-datepicker';
import 'vue2-datepicker/index.css';
export default {
name: 'Analytics-test',
components: {
DatePicker
},
data: () => ({
dateFrom: new Date('2021-12-01'),
dateTo: new Date(),
flagStartDate: false,
chartData: null,
labels: [],
dataset: {},
draftData: null,
data: [],
datacollection: [],
clubsId: ['5c3c5e12ba86198828baa4a7', '5c3c5e20ba86198828baa4c5', '60353d6edbb58a135bf41856', '61e9995d4ec0f29dc8447f81', '61e999fc4ec0f29dc844835e'],
}),
methods: {
draw() {
if (this.mychart) {
this.mychart.destroy();
}
const ctx = document.getElementById('main-chart');
this.mychart = new Chart(ctx,
{
type: 'line',
data: {
labels: this.labels,
datasets: this.datacollection
},
options: {
legend: {
display: true,
position: 'bottom',
},
responsive: true,
elements: {
line: {
// tension: 0, // disables bezier curves
// bezierCurve: false
}
},
scales: {
xAxes: [{
type: "time",
display: true,
// gridLines: {
// display: false
// },
scaleLabel: {
display: false,
// labelString: 'Time'
},
ticks: {
major: {
fontStyle: "bold",
fontColor: "#FF0000"
}
}
}],
yAxes: [
{
id: 'y1',
type: 'linear',
position: 'left',
display: false
},
{
id: 'y2',
type: 'linear',
position: 'right',
display: false
},
{
id: 'y3',
type: 'linear',
position: 'left',
display: false
},
{
id: 'y4',
type: 'linear',
position: 'right',
display: false
},
{
id: 'y5',
type: 'linear',
position: 'left',
display: false
},
{
display: false,
gridLines: {
display: false
},
scaleLabel: {
display: true,
labelString: this.labelY
},
ticks: {
min: 0, // it is for ignoring negative step.
beginAtZero: true,
stepSize: 100 // if i use this it always set it '1', which look very awkward if it have high value e.g. '100'.
}
}]
}
}
});
},
// Выручка
incomingsClub(clubId) {
switch (clubId) {
case '5c3c5e12ba86198828baa4a7':
return { label: "Выручка Фрунзенской", borderColor: "#3e95cd", fill: false }
case '5c3c5e20ba86198828baa4c5':
return { label: "Выручка Чернышевской", borderColor: "#8e5ea2", fill: false };
case '60353d6edbb58a135bf41856':
return { label: "Выручка Василеостровской", borderColor: "#e8c3b9", fill: false };
case '61e9995d4ec0f29dc8447f81':
return { label: "Выручка Московской", borderColor: "#3cba9f", fill: false };
case '61e999fc4ec0f29dc844835e':
return { label: "Выручка Лесной", borderColor: "#c45850", fill: false };
case 'all':
return { label: "Выручка сети", borderColor: "#8e8786", fill: false };
default:
return 'Неизвестный клуб';
}
},
async loadIncomings(clubsId) {
try {
for (let clubId in clubsId) {
clubId = clubsId[clubId]
let dateFrom = this.dateFrom
let dateTo = this.dateTo
let groupBy = 'month'
let potential = true
let definitely = true
await this.$store.dispatch('loadIncomings', { clubId, dateFrom, dateTo, groupBy, potential, definitely })
this.draftData = this.$store.state.incomings
if (this.labels.length === 0) {
this.getDates()
}
this.flagStartDate = true
await this.getIncomings(clubId)
this.flagStartDate = false
}
this.getIncomingsTotal()
// this.draw.mychart.update()
} catch (e) {
console.error(e)
}
},
getDates() {
for (let item in this.draftData) {
if (item === 'items') {
for (let elem in this.draftData[item]) {
this.labels.push(this.draftData[item][elem].date.slice(0, 7))
}
}
}
},
bindDataDates(indexDate) {
return Array(indexDate).fill(null);
},
getIncomings(clubId) {
for (let item in this.draftData) {
if (item === 'items') {
for (let elem in this.draftData[item]) {
let positionDate = this.labels.indexOf(this.draftData[item][elem].date.slice(0, 7))
if (this.flagStartDate && positionDate > 0) {
let zerroArray = this.bindDataDates(positionDate)
this.data = this.data.concat(zerroArray)
}
this.data.push(this.draftData[item][elem].amount)
this.flagStartDate = false
}
this.dataset.data = this.data
Object.assign(this.dataset, this.incomingsClub(clubId))
Object.assign(this.dataset, { yAxisID: 'y1' })
this.datacollection.push(this.dataset)
this.data = []
this.dataset = {}
}
}
},
getIncomingsTotal() {
for (let item in this.datacollection) {
if (!this.data.length) {
this.data = this.datacollection[item].data
continue
}
const firstArr = this.data
const secondArr = this.datacollection[item].data;
this.data = []
let length;
if (firstArr.length >= secondArr.length) {
length = firstArr.length;
} else {
length = secondArr.length;
}
for (let i = 0; i < length; i++) {
const a = firstArr[i] === undefined ? 0 : firstArr[i];
const b = secondArr[i] === undefined ? 0 : secondArr[i];
this.data.push(a + b);
}
}
this.dataset.data = this.data
Object.assign(this.dataset, this.incomingsClub('all'))
Object.assign(this.dataset, { yAxisID: 'y1' })
this.datacollection.push(this.dataset)
this.data = []
this.dataset = {}
},
// Средняя сумма за жизнь
avgIncomingsClub(clubId) {
omitted..
},
getDatesAvgIncome() {
omitted..
},
async loadAvgIncomings(clubsId) {
omitted..
},
getAvgIncomings(clubId) {
omitted..
},
// Среднее кол-во оплат
avgPaymentsClub(clubId) {
omitted..
},
async loadAvgPayments(clubsId) {
omitted..
},
getAvgPayments(clubId) {
omitted..
},
// Посещаемость
avgAttendanceClub(clubId) {
omitted..
},
async loadAvgSchedule(clubsId) {
omitted..
},
getAvgAttendance(clubId) {
omitted..
},
// Тренировок
participantsCountClub(clubId) {
omitted..
},
async loadTrainings(clubsId) {
omitted..
},
async getParticipantsCount(clubId) {
omitted..
},
watch: {
dateFrom() {
console.log('dateFrom changed to', this.dateFrom)
this.draw()
},
dateTo() {
console.log('dateTo changed to', this.dateTo)
this.draw()
}
},
async mounted() {
await this.loadIncomings(this.clubsId),
await this.loadAvgIncomings(this.clubsId),
await this.loadAvgPayments(this.clubsId),
await this.loadAvgSchedule(this.clubsId),
await this.loadTrainings(this.clubsId)
this.$nextTick(() => {
this.draw()
})
},
</script>
<style>
.container form {
display: flex;
}
</style>
I skipped code in other functions because it's doesn't matter. Situation with other the same.