通过 AJAX 请求根据用户输入重绘谷歌图表答案

【问题标题】：Redraw google chart based on user input via AJAX request通过 AJAX 请求根据用户输入重绘谷歌图表
【发布时间】：2016-12-21 05:38:08
【问题描述】：

我有一个从我的数据库中提取数据的谷歌图表，它可以按我的意愿工作。根据 URL 中的 get 请求，它从选定的表中提取数据。

我想根据从下拉菜单中选择的表格通过 ajax 更新此图表。我无法突破的部分是通过 ajax 让数据响应。我认为下面的代码很接近，但我得到了下面我似乎无法摆脱的错误。

getdata.php:22 Uncaught ReferenceError: $ is not defineddrawVisualization@getdata.php:22onchange@getdata.php:47

我尝试从 getdata.php 中删除 GET 请求并硬编码一个表，认为 $ 未定义，但这并没有解决错误。

工作图代码

<!DOCTYPE>
<html>
<head> 
<meta http-equiv="content-type" content="text/html; charset=utf-8"/>
<title>
Wind Graph
</title>
<script type="text/javascript" src="http://www.google.com/jsapi"></script>
<script type="text/javascript">
google.load('visualization', '1', {packages: ['corechart']});
</script>
<script type="text/javascript">

function drawVisualization() {

var data = new google.visualization.DataTable();

<?php
require("dbconnect.php");

echo " data.addColumn('string', 'Time');";
echo " data.addColumn('number', 'Wind_Speed');";
echo " data.addColumn('number', 'Wind_Gust');";

$db = mysql_connect($server, $user_name, $password);
mysql_select_db($database);

$sqlQuery = "SELECT * FROM ".$_GET['q']." WHERE Date(Time + INTERVAL 10 HOUR) = Date(UTC_TIMESTAMP() + INTERVAL 10 HOUR)";
$sqlResult = mysql_query($sqlQuery);
while ($row = mysql_fetch_assoc($sqlResult)) {

echo " data.addRow(['{$row['Time']}', {v: {$row['Wind_Speed']}, f: '{$row['Wind_Speed']}' }, {v: {$row['Wind_Gust']}, f: '{$row['Wind_Gust']}' } ]); ";

}

?>

// Create and draw the visualization.
new google.visualization.LineChart(document.getElementById('visualization')).
draw(data, {curveType: "none",
title: "AU0001 Wind Chart",
titleTextStyle: {color: "orange"},
//width: 800, height: 400,
//vAxis: {maxValue: 10},
vAxis: {minValue: 0},
vAxis: {title: 'Wind Speed (Knots)'},
vAxis: {baseline: 0},
vAxis: {gridlines: {count: 10}  },
vAxis: {title: "Wind Speed (Knots)", titleTextStyle: {color: "orange"}},
hAxis: {title: "Time", titleTextStyle: {color: "orange"}},
interpolateNulls: 1
}
);
}

google.setOnLoadCallback(drawVisualization);
</script>
</head>
<body>
<div id="visualization" style="width: 100%; height: 400px;"></div>
</body>
</html>

带有 AJAX 请求的新代码

<!DOCTYPE>
<html>
<head> 
<meta http-equiv="content-type" content="text/html; charset=utf-8"/>
<title>
Wind Graph
</title>
<script type="text/javascript" src="http://www.google.com/jsapi"></script>
<script type="text/javascript">
google.load('visualization', '1', {packages: ['corechart']});
</script>
<script type="text/javascript">

function drawVisualization(num) {

var data = new google.visualization.DataTable(TableData);
var TableData = $.ajax({
  url: "getdata.php",
  data: "q="+num,
  dataType:"json",
  async: false
}).responseText;

// Create and draw the visualization.
new google.visualization.LineChart(document.getElementById('visualization')).
draw(data, {curveType: "none",
title: "Wind Chart",
titleTextStyle: {color: "orange"},
//width: 800, height: 400,
//vAxis: {maxValue: 10},
vAxis: {minValue: 0},
vAxis: {title: 'Wind Speed (Knots)'},
vAxis: {baseline: 0},
vAxis: {gridlines: {count: 10}  },
vAxis: {title: "Wind Speed (Knots)", titleTextStyle: {color: "orange"}},
hAxis: {title: "Time", titleTextStyle: {color: "orange"}},
interpolateNulls: 1
}
);
}

//  google.setOnLoadCallback(drawVisualization);
</script>
</head>
<body style="font-family: Arial;border: 0 none;">
<form>
<select name="users" onchange="drawVisualization(this.value)">
<option value="">Select unit:</option>
<option value="0001">0001</option>
<option value="0002">0002</option>

</select>
</form>
<div id="visualization" style="width: 100%; height: 400px;"></div>
</body>
</html>

getdata.php 代码

<?php
require("dbconnect.php");

echo " data.addColumn('string', 'Time');";
echo " data.addColumn('number', 'Wind_Speed');";
echo " data.addColumn('number', 'Wind_Gust');";

$db = mysql_connect($server, $user_name, $password);
mysql_select_db($database);


$sqlQuery = "SELECT * FROM ".$_GET['q']." WHERE Date(Time + INTERVAL 10 HOUR) = Date(UTC_TIMESTAMP() + INTERVAL 10 HOUR)";
$sqlResult = mysql_query($sqlQuery);
while ($row = mysql_fetch_assoc($sqlResult)) {

echo " data.addRow(['{$row['Time']}', {v: {$row['Wind_Speed']}, f: '{$row['Wind_Speed']}' }, {v: {$row['Wind_Gust']}, f: '{$row['Wind_Gust']}' } ]); ";

}

?>

【问题讨论】：

标签： php ajax google-visualization

【解决方案1】：

推荐使用php获取google接受的格式的json

以下是使用ajax从php获取json数据并绘制google图表的完整示例

php

<?php
  require("dbconnect.php");

  $db = mysql_connect($server, $user_name, $password);
  mysql_select_db($database);

  $sqlQuery = "SELECT * FROM ".$_GET['q']." WHERE Date(Time + INTERVAL 10 HOUR) = Date(UTC_TIMESTAMP() + INTERVAL 10 HOUR)";
  $sqlResult = mysql_query($sqlQuery);

  $rows = array();
  $table = array();

  $table['cols'] = array(
      array('label' => 'Time', 'type' => 'string'),
      array('label' => 'Wind_Speed', 'type' => 'number'),
      array('label' => 'Wind_Gust', 'type' => 'number')
  );

  while ($row = mysql_fetch_assoc($sqlResult)) {
    $temp = array();
    $temp[] = array('v' => (string) $row['Time']);
    $temp[] = array('v' => (float) $row['Wind_Speed']);
    $temp[] = array('v' => (float) $row['Wind_Gust']);
    $rows[] = array('c' => $temp);
  }

  $table['rows'] = $rows;

  echo json_encode($table);
?>

不推荐使用 --> async: false
或内联事件处理程序 --> <select name="users" onchange="drawVisualization(this.value)">

另外，hAxis 和 vAxis 在图表选项中只能出现一次

html/javascript

<!DOCTYPE>
<html>
  <head>
    <meta http-equiv="content-type" content="text/html; charset=utf-8"/>
    <title>
      Wind Graph
    </title>
    <script src="http://www.google.com/jsapi"></script>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
    <script>
      google.load('visualization', '1', {
        // google-vis callback
        callback: function () {
          // add event listener to select element
          $("#users").change(drawChart);

          function drawChart() {
            $.ajax({
              url: 'getdata.php',
              // use value from select element
              data: 'q=' + $("#users").val(),
              dataType: 'json',
              success: function (responseText) {
                // use response from php for data table
                var data = new google.visualization.DataTable(responseText);
                new google.visualization.LineChart(document.getElementById('visualization')).
                draw(data, {
                  curveType: 'none',
                  title: 'Wind Chart',
                  titleTextStyle: {
                    color: 'orange'
                  },
                  interpolateNulls: 1
                });
              },
              error: function(jqXHR, textStatus, errorThrown) {
                console.log(errorThrown + ': ' + textStatus);
              }
            });
          }
        },
        packages: ['corechart']
      });
    </script>
  </head>
  <body style="font-family: Arial;border: 0 none;">
    <form>
      <select id="users">
        <option value="" selected disabled>Select unit:</option>
        <option value="0001">0001</option>
        <option value="0002">0002</option>
      </select>
    </form>
    <div id="visualization" style="width: 100%; height: 400px;"></div>
  </body>
</html>

【讨论】：

嗨@WhiteHat，感谢您的帮助！我在 html 文件的页面加载时收到以下错误： graphindexnew1.php:14 Uncaught ReferenceError: $ is not definedcallback @ graphindexnew1.php:14 它指向这行代码$("#users").change(drawChart);
您是否在某处包含了 jquery？假设它在那里，$.ajax 已经在那里，请参阅上面答案的编辑..
就是这样！非常感谢你！上面的代码有效