javascript - Vue Chart.js - 数据更改时图表不更新

Question

我正在使用 Vue.js 和 Chart.js 来绘制一些图表。每次我调用该函数generateChart()时，图表都不会自动更新。当我检查 Vue Devtools 中的数据时，它们是正确的，但图表没有反映数据。但是，当我调整窗口大小时，图表会更新。

我在做什么有什么问题？
每次打电话时如何更新图表generateChart()？

我觉得这将与object更改array检测警告有关，但我不确定该怎么做。

https://codepen.io/anon/pen/bWRVKB?editors=1010

<template>
    <el-dialog title="Chart" v-model="showGeneratedChart">
        <line-chart :chartData="dataChart"></line-chart>
    </el-dialog>
</template>

<script>
export default {
    data() {
        const self = this;
        return {
            dataChart: {
                labels: [],
                datasets: [
                    {
                        label: "label",
                        backgroundColor: "#FC2525",
                        data: [0, 1, 2, 3, 4],
                    },
                ],
            },
        };
    },
    methods: {
        generateChart() {
            this.dataChart["labels"] = [];
            this.dataChart["datasets"] = [];

            // ... compute datasets and formattedLabels

            this.dataChart["labels"] = formattedLabels;
            this.dataChart["datasets"] = datasets;
        },
    },
};
</script>

LineChart.js

import { Line, mixins } from 'vue-chartjs'

export default Line.extend({
    mixins: [mixins.reactiveProp],
    props: ["options"],
    mounted () {
        this.renderChart(this.chartData, this.options)
    }
})

score 48 · Accepted Answer

Use a computed property for the chart data. And instead of calling this.renderChart on watch wrap it in a method and reuse that method on mounted and in watch.

Vue.component("line-chart", {
  extends: VueChartJs.Line,
  props: ["data", "options"],
  mounted() {
    this.renderLineChart();
  },
  computed: {
    chartData: function() {
      return this.data;
    }
  },
  methods: {
    renderLineChart: function() {
    this.renderChart(
      {
        labels: [
          "January",
          "February",
          "March",
          "April",
          "May",
          "June",
          "July"
        ],
        datasets: [
          {
            label: "Data One",
            backgroundColor: "#f87979",
            data: this.chartData
          }
        ]
      },
      { responsive: true, maintainAspectRatio: false }
    );      
    }
  },
  watch: {
    data: function() {
      this._chart.destroy();
      //this.renderChart(this.data, this.options);
      this.renderLineChart();
    }
  }
});

var vm = new Vue({
  el: ".app",
  data: {
    message: "Hello World",
    dataChart: [10, 39, 10, 40, 39, 0, 0],
    test: [4, 4, 4, 4, 4, 4]
  },
  methods: {
    changeData: function() {
      this.dataChart = [6, 6, 3, 5, 5, 6];
    }
  }
});

<!DOCTYPE html>
<html>
<head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width">
  <title>Vue.jS Chart</title>
</head>
<body>
<div class="app">
    {{ dataChart }}
   <button v-on:click="changeData">Change data</button>
  <line-chart :data="dataChart" :options="{responsive: true, maintainAspectRatio: false}"></line-chart>
 
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.2.6/vue.min.js"></script>
<script src="https://unpkg.com/vue-chartjs@2.5.7-rc3/dist/vue-chartjs.full.min.js"></script>
</body>
</html>

You could also make the options a computed property, and if option not going to change much you can setup default props. https://vuejs.org/v2/guide/components.html#Prop-Validation

Here is a working codepen https://codepen.io/azs06/pen/KmqyaN?editors=1010

score 5 · Accepted Answer

我的解决方案是不使用 mixins 并使用监视道具。

watch: {
    chartData: function() {
        this.renderChart(this.chartData, this.options);
    }
  }

但是，这在我更改另一个组件中的 chartData 之前不起作用，如下所示：

this.chartData = {
            labels: [],
            datasets: []
};
this.chartData.labels = labels;
this.chartData.datasets = datasets;

如果我只是替换标签和数据集，手表就不会触发。

score 4 · Accepted Answer

watch: {
chartData: function (newData, oldData) {
  // let ctx = document.getElementById('doughnut-chart').getContext('2d')
  // console.log(ctx)
  // var chart = new Chart(ctx, {type: 'doughnut', data:, options: self.options})
  // // chart.config.data.datasets.push(newData)
  // chart.config.options.animation = false
  // console.log(chart)
  // chart.config.data.datasets.push(newData)
  // chart.config.optionsNoAnimation = optionsNoAnimation
  // console.log(chart.config.data.datasets.push(newData))
  // this.dataset = newData
  // chart.update()
  // console.log('options', this.data)
  console.log('new data from watcher', newData)
  this.data.datasets[0].data = newData
  this.renderChart(this.data, this.options)
}
}

添加自定义观察者以更新任何 vue 图表图形

score 2 · Accepted Answer

我以前从未使用过 vue-chartjs，但看起来您唯一的问题是您忘记在折线图组件中明确接收 chartData 作为道具：

改变

export default Line.extend({
    mixins: [mixins.reactiveProp],
    props: ["options"],
    mounted () {
        this.renderChart(this.chartData, this.options)
    }
})

和

export default Line.extend({
    mixins: [mixins.reactiveProp],
    props: ["chartData", "options"],
    mounted () {
        this.renderChart(this.chartData, this.options)
    }
})

另外，在更改对象时要注意 vue 反应性问题，这不起作用：

this.dataChart['datasets'] = datasets;

你必须做这样的事情：

Vue.set(this.dataChart, 'datasets', datasets);

以便 Vue 检测对象的变化。

有关反应性的更多信息： https ://vuejs.org/v2/guide/reactivity.html

有关图表反应性的更多信息：http: //vue-chartjs.org/#/home ?id=reactive-data

score 2 · Accepted Answer

我只是在 nextTick 上重新渲染它而没有破坏并且工作正常。

(vue 3, vue3-chart-v2:0.8.2)

mounted () {
    this.renderLineChart();
},
methods: {
    renderLineChart() {
        this.renderChart(this.chartData, this.chartOptions);
    }
},
watch: {
    chartData () {
        this.$nextTick(() => {
            this.renderLineChart();
        })
    }
}

score 1 · Accepted Answer

您的解决方案实际上几乎是正确的。您不能直接修改图表数据集的子属性。您必须设置this.datachart对象本身。默认的 mixinmixins.reactiveProp会自动为组件的chartData属性添加一个观察者。请参阅此处的文档。这就是为什么如果没有进一步的代码就无法修改子属性，请参阅其他答案。

generateChart() {
    // If you want to clear all chart data (not necessary)
    this.dataChart = {}

    // Compute datasets and formattedLabels
    let formattedLabels = ...
    let datasets = ...

    this.dataChart = {
        labels: formattedLabels,
        datasets: datasets
    }
}

javascript - Vue Chart.js - 数据更改时图表不更新

LineChart.js

6 回答 6

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