Populating Data Using Server-Side Code

Chart data can be populated using server-side code by loading local files, querying databases, or other methods.
The provided example demonstrates using PHP to read chart data from a local text file.
The example utilizes jQuery to fetch JSON data from a server-side PHP script and display it in a pie chart using the Google Visualization API.
The getData.php file reads and returns the content of a local sampleData.json file, which is formatted as a Google DataTable.
The exampleUsingPHP.html file uses the fetched JSON data to create and render a pie chart on the webpage.

You can use server-side code to acquire data to populate your chart. Your server-side code can load a local file, query a database, or get the data in some other way. The following PHP example demonstrates reading chart data from a local text file when a page is requested. You can copy these files to your own server, if it supports PHP.

Note: This sample requires jQuery version 1.6.2 or later.

exampleUsingPHP.html file

This is the file that the user browses to. The drawChart() function calls the jQuery ajax() function to send a query to a URL and get back a JSON string. The URL here is of the local getData.php file. The returned data is actually a DataTable defined in the local sampleData.json file. This DataTable is used to populate a pie chart, which is then rendered on the page.

<html>
  <head>
    <!--Load the AJAX API-->
    <script type="text/javascript" src="https://www.gstatic.com/charts/loader.js"></script>
    <script type="text/javascript" src="//ajax.googleapis.com/ajax/libs/jquery/1.10.2/jquery.min.js"></script>
    <script type="text/javascript">
    
    // Load the Visualization API and the piechart package.
    google.charts.load('current', {'packages':['corechart']});
      
    // Set a callback to run when the Google Visualization API is loaded.
    google.charts.setOnLoadCallback(drawChart);
      
    function drawChart() {
      var jsonData = $.ajax({
          url: "getData.php",
          dataType: "json",
          async: false
          }).responseText;
          
      // Create our data table out of JSON data loaded from server.
      var data = new google.visualization.DataTable(jsonData);

      // Instantiate and draw our chart, passing in some options.
      var chart = new google.visualization.PieChart(document.getElementById('chart_div'));
      chart.draw(data, {width: 400, height: 240});
    }

    </script>
  </head>

  <body>
    <!--Div that will hold the pie chart-->
    <div id="chart_div"></div>
  </body>
</html>

getData.php File

When this file receives a request, it returns a copy of the local sampleData.json file.

<?php 

// This is just an example of reading server side data and sending it to the client.
// It reads a json formatted text file and outputs it.

$string = file_get_contents("sampleData.json");
echo $string;

// Instead you can query your database and parse into JSON etc etc

?>

sampleData.json File

A JSON version of a small DataTable.

{
  "cols": [
        {"id":"","label":"Topping","pattern":"","type":"string"},
        {"id":"","label":"Slices","pattern":"","type":"number"}
      ],
  "rows": [
        {"c":[{"v":"Mushrooms","f":null},{"v":3,"f":null}]},
        {"c":[{"v":"Onions","f":null},{"v":1,"f":null}]},
        {"c":[{"v":"Olives","f":null},{"v":1,"f":null}]},
        {"c":[{"v":"Zucchini","f":null},{"v":1,"f":null}]},
        {"c":[{"v":"Pepperoni","f":null},{"v":2,"f":null}]}
      ]
}

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