Question

我在一个简单的Bootstrap html文件中有以下代码，它显示了Chart.js折线图。

    <div class="card-block chartjs">
       <canvas id="line-chart" height="500"></canvas>
    </div>

包含图表设置的js文件如下所示：

$(window).on("load", function(){

    var ctx = $("#line-chart");

    var chartOptions = {
        responsive: true,
        maintainAspectRatio: false,
        legend: {
            position: 'bottom',
        },
        hover: {
            mode: 'label'
        },
        scales: {
            xAxes: [{
                display: true,
                gridLines: {
                    color: "#f3f3f3",
                    drawTicks: false,
                },
                scaleLabel: {
                    display: true,
                    labelString: 'Month'
                }
            }],
            yAxes: [{
                display: true,
                gridLines: {
                    color: "#f3f3f3",
                    drawTicks: false,
                },
                scaleLabel: {
                    display: true,
                    labelString: 'Value'
                }
            }]
        },
        title: {
            display: true,
            text: 'Chart.js Line Chart - Legend'
        }
    };

    var chartData = {
        labels: ["January", "February", "March", "April", "May", "June", "July"],
        datasets: [{
            label: "My First dataset",
            data: [65, 59, 80, 81, 56, 55, 40],
            fill: false,
            borderDash: [5, 5],
            borderColor: "#9C27B0",
            pointBorderColor: "#9C27B0",
            pointBackgroundColor: "#FFF",
            pointBorderWidth: 2,
            pointHoverBorderWidth: 2,
            pointRadius: 4,
        }, {
            label: "My Second dataset",
            data: [28, 48, 40, 19, 86, 27, 90],
            fill: false,
            borderDash: [5, 5],
            borderColor: "#00A5A8",
            pointBorderColor: "#00A5A8",
            pointBackgroundColor: "#FFF",
            pointBorderWidth: 2,
            pointHoverBorderWidth: 2,
            pointRadius: 4,
        }, {
            label: "My Third dataset - No bezier",
            data: [45, 25, 16, 36, 67, 18, 76],
            lineTension: 0,
            fill: false,
            borderColor: "#FF7D4D",
            pointBorderColor: "#FF7D4D",
            pointBackgroundColor: "#FFF",
            pointBorderWidth: 2,
            pointHoverBorderWidth: 2,
            pointRadius: 4,
        }]
    };

    var config = {
        type: 'line',

        options : chartOptions,

        data : chartData
    };

    var lineChart = new Chart(ctx, config);
});

我想避免使用单独的javascript文件，而只是在Jinja2 / Flask html页面中包含所有内容。可以在this tutorial中找到一个工作示例，这与我想要遵循的方式相同。我试图将js部分的任何粘贴复制到我的html页面并放在<script>标签之间，但不幸的是它不起作用。

以下是我尝试的方式：

# in my jinja2/flask html page
<div class="card-body collapse in">
    <div class="card-block chartjs">
        <canvas id="line-chart" height="500"></canvas>
    </div>
</div>
<script>
    var ctx = $("#line-chart");
    var chartOptions = {
        responsive: true,
        maintainAspectRatio: false,
        legend: {
            position: 'bottom',
        },
        hover: {
            mode: 'label'
        },
        scales: {
            xAxes: [{
                display: true,
                gridLines: {
                    color: "#f3f3f3",
                    drawTicks: false,
                },
                scaleLabel: {
                    display: true,
                    labelString: 'Month'
                }
            }],
            yAxes: [{
                display: true,
                gridLines: {
                    color: "#f3f3f3",
                    drawTicks: false,
                },
                scaleLabel: {
                    display: true,
                    labelString: 'Value'
                }
            }]
        },
        title: {
            display: true,
            text: 'Chart.js Line Chart - Legend'
        }
    };

    // Chart Data
    var chartData = {
        labels: ["January", "February", "March", "April", "May", "June", "July"],
        datasets: [{
            label: "My First dataset",
            data: [65, 59, 80, 81, 56, 55, 40],
            fill: false,
            borderDash: [5, 5],
            borderColor: "#9C27B0",
            pointBorderColor: "#9C27B0",
            pointBackgroundColor: "#FFF",
            pointBorderWidth: 2,
            pointHoverBorderWidth: 2,
            pointRadius: 4,
        }, {
            label: "My Second dataset",
            data: [28, 48, 40, 19, 86, 27, 90],
            fill: false,
            borderDash: [5, 5],
            borderColor: "#00A5A8",
            pointBorderColor: "#00A5A8",
            pointBackgroundColor: "#FFF",
            pointBorderWidth: 2,
            pointHoverBorderWidth: 2,
            pointRadius: 4,
        }, {
            label: "My Third dataset - No bezier",
            data: [45, 25, 16, 36, 67, 18, 76],
            lineTension: 0,
            fill: false,
            borderColor: "#FF7D4D",
            pointBorderColor: "#FF7D4D",
            pointBackgroundColor: "#FFF",
            pointBorderWidth: 2,
            pointHoverBorderWidth: 2,
            pointRadius: 4,
        }]
    };

    var config = {
        type: 'line',

        // Chart Options
        options : chartOptions,

        data : chartData
    };

    // Create the chart
    var lineChart = new Chart(ctx, config);
});
</script>

不幸的是，我对JS并不熟悉，也不知道如何在我的Flask应用中显示图表。如果有人能够向我展示我需要实施的必要修改以使其工作，我将非常感激。

Answer 1

首先确保在模板中引用所需的JS（或它扩展的模板）。

假设您从static/js文件夹中提供服务：

<head>
    ...
    <script src='/static/js/Chart.bundle.min.js'></script>
    ...
</head>

您的脚本标记内容看起来非常精细，只需稍加修改即可获得上下文，并且您似乎需要删除一个尾随});：

<script>
    // get context
    var ctx = document.getElementById("line-chart").getContext("2d");

    ....

    // Create the chart
    var lineChart = new Chart(ctx, config);

    // REMOVE THIS FROM THE END OF YOUR SCRIPT
    //});
</script>

Answer 2

正如bgse在他的回答中所说，你需要先加载库。我建议您使用CDN，因为您不需要下载ChartJS库。

其次，您正在编写一些可能在将库提取到页面之前执行的JS。那么我要补充的是：

<div class="card-body collapse in">
    <div class="card-block chartjs">
        <canvas id="line-chart" height="500"></canvas>
    </div>
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/Chart.js/2.6.0/Chart.min.js"></script>
<script src="https://code.jquery.com/jquery-3.2.1.min.js" integrity="sha256-hwg4gsxgFZhOsEEamdOYGBf13FyQuiTwlAQgxVSNgt4=" crossorigin="anonymous"></script>
<script>
    $(document).ready(function(){
        // Your JS code here
        // ...
    });
</script>

这样，当加载所有JS时，脚本代码就会执行。

将Chart.js折线图添加到js文件中的Jinja2 / Flask html页面

2 个答案: