Jinja通過“ SyntaxError：預期的屬性名稱，得到了'％'”錯誤

Question

我將Flask框架與render_template一起使用。 Flask返回列表到if.html文件。 我在if.html文件中使用Chart.js從燒瓶返回的列表中創建圖形。 當我使用HTML里面的chart.js之代碼文件，它工作正常，但是當我想同樣的JavaScript代碼復制到外部line.js文件，並鏈接回我的whether.html然后我看到語法錯誤：預期的屬性名稱，在控制台中出現“％” JavaScript錯誤。

對於這個問題，我將不勝感激。

在if.html中的JavaScript

{% extends "index.html" %}
{% block content %}
<!-- bar chart canvas element -->
<canvas id="myChart" width="600" height="400"></canvas>
<p id="pointSelected">Point selected:</p>

<script>
  // Global parameters:
  // do not resize the chart canvas when its container does (keep at 600x400px)
  Chart.defaults.global.responsive = false;

  // define the chart data
  var chartData = {
    labels : [{% for item in labels %}
               "{{item}}",
              {% endfor %}],
    datasets : [{
        label: '{{ legend }}',
        fill: false,
        lineTension: 0.1,
        backgroundColor: "rgba(75,192,192,0.4)",
        borderColor: "rgba(75,192,192,1)",
        borderCapStyle: 'butt',
        borderDash: [],
        borderDashOffset: 0.0,
        borderJoinStyle: 'miter',
        pointBorderColor: "rgba(75,192,192,1)",
        pointBackgroundColor: "#fff",
        pointBorderWidth: 1,
        pointHoverRadius: 5,
        pointHoverBackgroundColor: "rgba(75,192,192,1)",
        pointHoverBorderColor: "rgba(220,220,220,1)",
        pointHoverBorderWidth: 2,
        pointRadius: 1,
        pointHitRadius: 10,
        data : [{% for item in values %}
                  {{item}},
                {% endfor %}],
        spanGaps: false
    },

    {
        label: 'Sensor 2',
        fill: false,
        lineTension: 0.1,
        borderColor: "#3e95cd",
        data : [{% for item in values %}
                  {{item + 3}},
                {% endfor %}],

    }
    ]
  }

  // get chart canvas
  var holder = document.getElementById("myChart");
  var ctx = document.getElementById("myChart").getContext("2d");

  // create the chart using the chart canvas
  var myChart = new Chart(ctx, {
    type: 'line',
    data: chartData,
    options: {
      tooltips: {
        enabled: true,
        mode: 'single',
        callbacks: {
          label: function(tooltipItems, data) {
                   return tooltipItems.yLabel + ' degrees';
                 }
        }
      },
    }
  });

  // get the text element below the chart
  var pointSelected = document.getElementById("pointSelected");

  // create a callback function for updating the selected index on the chart
  holder.onclick = function(evt){
    var activePoint = myChart.getElementAtEvent(evt);
    console.log(activePoint);
    console.log('x:' + activePoint[0]._view.x);
    console.log('maxWidth: ' + activePoint[0]._xScale.maxWidth);
    console.log('y: ' + activePoint[0]._view.y);
    console.log('index: ' + activePoint[0]._index);
    pointSelected.innerHTML = 'Point selected... index: ' + activePoint[0]._index;
  };
</script>

{% endblock %}

line.js文件

  // Global parameters:
  // do not resize the chart canvas when its container does (keep at 600x400px)
  Chart.defaults.global.responsive = false;

  // define the chart data
  var chartData = {
    labels : [{% for item in labels %}
               "{{item}}",
              {% endfor %}],
    datasets : [{
        label: '{{ legend }}',
        fill: false,
        lineTension: 0.1,
        backgroundColor: "rgba(75,192,192,0.4)",
        borderColor: "rgba(75,192,192,1)",
        borderCapStyle: 'butt',
        borderDash: [],
        borderDashOffset: 0.0,
        borderJoinStyle: 'miter',
        pointBorderColor: "rgba(75,192,192,1)",
        pointBackgroundColor: "#fff",
        pointBorderWidth: 1,
        pointHoverRadius: 5,
        pointHoverBackgroundColor: "rgba(75,192,192,1)",
        pointHoverBorderColor: "rgba(220,220,220,1)",
        pointHoverBorderWidth: 2,
        pointRadius: 1,
        pointHitRadius: 10,
        data : [{% for item in values %}
                  {{item}},
                {% endfor %}],
        spanGaps: false
    },

    {
        label: 'Sensor 2',
        fill: false,
        lineTension: 0.1,
        borderColor: "#3e95cd",
        data : [{% for item in values %}
                  {{item + 3}},
                {% endfor %}],

    }
    ]
  }

  // get chart canvas
  var holder = document.getElementById("myChart");
  var ctx = document.getElementById("myChart").getContext("2d");

  // create the chart using the chart canvas
  var myChart = new Chart(ctx, {
    type: 'line',
    data: chartData,
    options: {
      tooltips: {
        enabled: true,
        mode: 'single',
        callbacks: {
          label: function(tooltipItems, data) {
                   return tooltipItems.yLabel + ' degrees';
                 }
        }
      },
    }
  });

  // get the text element below the chart
  var pointSelected = document.getElementById("pointSelected");

  // create a callback function for updating the selected index on the chart
  holder.onclick = function(evt){
    var activePoint = myChart.getElementAtEvent(evt);
    console.log(activePoint);
    console.log('x:' + activePoint[0]._view.x);
    console.log('maxWidth: ' + activePoint[0]._xScale.maxWidth);
    console.log('y: ' + activePoint[0]._view.y);
    console.log('index: ' + activePoint[0]._index);
    pointSelected.innerHTML = 'Point selected... index: ' + activePoint[0]._index;
  };

if.html文件

{% extends "index.html" %}
{% block content %}

<!-- <script src='static/Chart.min.js'></script> -->
<script src='static/js/Chart.js'></script>
<script src='static/js/line.js'></script>
<!-- <canvas id="line-chart" width="300" height="150"></canvas> -->

<h1>Temperature Sensor #1</h1>
    <!-- bar chart canvas element -->
    <canvas id="myChart" width="600" height="400"></canvas>
    <p id="pointSelected">Point selected:</p>
{% endblock %}

Answer 1

Jinja僅適用於html文件，您不能在其他文件中使用它的標簽。 但是，您可以簡單地用變量來渲染小腳本，該變量在html模板中包含所需的值，然后在外部腳本中使用它們，例如：

    {% extends "index.html" %}
    {% block content %}
    <!-- bar chart canvas element -->
    <canvas id="myChart" width="600" height="400"></canvas>
    <p id="pointSelected">Point selected:</p>

    <script>
        var labels = [{% for item in labels %}
           "{{item}}",
          {% endfor %}]
        var data = [{% for item in values %}
              {{item}},
            {% endfor %}]
        // and so on for each variable
        // it's important to import external script 
        // after variables declaration, not before
    </script>

    <script src="external-script.js"></script>

    {% endblock %}

然后您可以簡單地在外部腳本中使用它們，例如：

    var chartData = {
        labels : labels,
        // and so on
    };