javascript - 使用 WKHTMLTOPDF 工具以 pdf 形式渲染 JS 图表

Question

我正在使用WKHTMLTOPDF用于打印 HTML 页面。一切正常，但 JS 图表未呈现。我尝试渲染图表

http://www.amcharts.com/tips/plotting-a-bell-curve-chart/

但 pdf 中的页面变为空白。

我尝试过的:

我尝试了以下命令来渲染 HTML:

wkhtmltopdf http://example.com/bell.php --javascript-delay 2000 bell.pdf

其中参数 --javascript-delay 2000 用于显示 JS 图表，并为 HTML 页面提供时间来渲染所有必需的 JS。

我的问题:-

Is it possible to render the JS charts in PDF using WKHTMLTOPDF ? If yes than where i'm going wrong ?

Chart Code is :

<style>
    #chartdiv {
    width       : 100%;
    height      : 500px;
    font-size   : 11px;
}           
</style>
<script type="text/javascript" src="http://www.amcharts.com/lib/3/amcharts.js"></script>
<script type="text/javascript" src="http://www.amcharts.com/lib/3/serial.js"></script>
<script type="text/javascript" src="http://www.amcharts.com/lib/3/themes/light.js"></script>
<div id="chartdiv"></div>
<script>
    /*  probability.js    12-25-2008    JavaScript
  Copyright (C)2008 Steven Whitney.
  Initially published by http://25yearsofprogramming.com.

  This program is free software; you can redistribute it and/or
  modify it under the terms of the GNU General Public License (GPL)
  Version 3 as published by the Free Software Foundation.
  This program is distributed in the hope that it will be useful,
  but WITHOUT ANY WARRANTY; without even the implied warranty of
  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  GNU General Public License for more details.
  You should have received a copy of the GNU General Public License
  along with this program; if not, write to the Free Software
  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA.

Functions related to probability calculations.

*/
//----------------------------------------------------------------------------------------------
// Calculates a point Z(x), the Probability Density Function, on any normal curve. 
// This is the height of the point ON the normal curve.
// For values on the Standard Normal Curve, call with Mean = 0, StdDev = 1.
function NormalDensityZx( x, Mean, StdDev ) {
    var a = x - Mean;
    return Math.exp( -( a * a ) / ( 2 * StdDev * StdDev ) ) / ( Math.sqrt( 2 * Math.PI ) * StdDev );
  }
  //----------------------------------------------------------------------------------------------
  // Calculates Q(x), the right tail area under the Standard Normal Curve. 
function StandardNormalQx( x ) {
    if ( x === 0 ) // no approximation necessary for 0
      return 0.50;

    var t1, t2, t3, t4, t5, qx;
    var negative = false;
    if ( x < 0 ) {
      x = -x;
      negative = true;
    }
    t1 = 1 / ( 1 + ( 0.2316419 * x ) );
    t2 = t1 * t1;
    t3 = t2 * t1;
    t4 = t3 * t1;
    t5 = t4 * t1;
    qx = NormalDensityZx( x, 0, 1 ) * ( ( 0.319381530 * t1 ) + ( -0.356563782 * t2 ) +
      ( 1.781477937 * t3 ) + ( -1.821255978 * t4 ) + ( 1.330274429 * t5 ) );
    if ( negative == true )
      qx = 1 - qx;
    return qx;
  }
  //----------------------------------------------------------------------------------------------
  // Calculates P(x), the left tail area under the Standard Normal Curve, which is 1 - Q(x). 
function StandardNormalPx( x ) {
    return 1 - StandardNormalQx( x );
  }
  //----------------------------------------------------------------------------------------------
  // Calculates A(x), the area under the Standard Normal Curve between +x and -x. 
function StandardNormalAx( x ) {
    return 1 - ( 2 * StandardNormalQx( Math.abs( x ) ) );
  }
  //----------------------------------------------------------------------------------------------

/**
 * Define values where to put vertical lines at
 */
var verticals = [
  -1.4, -0.2, 1.2
];

/**
 * Calculate data
 */
var chartData = [];
for ( var i = -5; i < 5.1; i += 0.1 ) {
  var dp = {
    category: i,
    value: NormalDensityZx( i, 0, 1 )
  };
  if ( verticals.indexOf( Math.round( i * 10 ) / 10 ) !== -1 ) {
    dp.vertical = dp.value;
  }
  chartData.push( dp );
}

/**
 * Create a chart
 */
var chart = AmCharts.makeChart( "chartdiv", {
  "type": "serial",
  "theme": "light",
  "dataProvider": chartData,
  "precision": 2,
  "valueAxes": [ {
    "gridAlpha": 0.2,
    "dashLength": 0
  } ],
  "startDuration": 1,
  "graphs": [ {
    "balloonText": "[[category]]: <b>[[value]]</b>",
    "lineThickness": 3,
    "valueField": "value"
  }, {
    "balloonText": "",
    "fillAlphas": 1,
    "type": "column",
    "valueField": "vertical",
    "fixedColumnWidth": 2,
    "labelText": "[[value]]",
    "labelOffset": 20
  } ],
  "chartCursor": {
    "categoryBalloonEnabled": false,
    "cursorAlpha": 0,
    "zoomable": false
  },
  "categoryField": "category",
  "categoryAxis": {
    "gridAlpha": 0.05,
    "startOnAxis": true,
    "tickLength": 5,
    "labelFunction": function( label, item ) {
      return '' + Math.round( item.dataContext.category * 10 ) / 10;
    }
  }

} );
</script> 

Answer 1

我知道这已经晚了，但我刚刚解决了这个问题，您需要为您的#chartdiv设置指定的宽度，尝试这个新的样式标签:

<style>
    #chartdiv {
    width       : 750px;
    height      : 500px;
    font-size   : 11px;
}           
</style>