PHPChartsJs

PHPHistogram is a comprehensive collection of functions that simplifies the process of generating histograms/charts for web pages served through PHP. It leverages PHP and Charts.js to create dynamic histograms from arrays, commonly obtained from queries returned by a MySQL database.

Demo Link: http://josephiturner.com/PHPChartsJs_Example.html

Usage

To use PHPChartsJs, follow these steps:

1. Ensure that Chart.js is included somewhere in your page using the following script tag: <script src="https://cdn.jsdelivr.net/npm/chart.js"></script>

2. Include the PHPChartsJs library in your PHP page by adding the following line of code: include_once('PHPCharts.php');

3. Prepare the data you wish to visualize by creating an array of keyed arrays (basically a JSON). If you are querying a MySQL database, you can conveniently generate this array using the queryToArray($connection, $query) function, or the native mysqli_fetch_all($result, MYSQLI_ASSOC) function.

4. Generate a histogram by calling the generateHistogram($data, $columnName) function, providing the data array and the desired field for plotting. This function will return an HTML string containing the generated histogram.

5. If you want to generate multiple parallel histograms from the same data array, you can use the generateMultiHistogram($data, $columnNames) function. The $columnNames argument should be an array of the fields you want to plot.

6. To automatically generate histograms for all possible fields in the data array, pass the result of the getColumnNames($data) function as the $columnNames argument to the generateMultiHistogram($data, $columnNames) function.

7. Make stacked bar charts using the generateStackedBarChart($data, $x_key, $y_key, $stack_key) function. $x_key is the array key for the fields to be plotted along the x axis. $y_key is the array key for the fields to be plotted along the y axis. $stack_key is the array key to separate values into stacks in the y dimension. Take a look at the Charts.Js documentation to see more: https://www.chartjs.org/docs/latest/samples/bar/stacked.html

Example

Here's an example code snippet demonstrating the usage of PHPChartsJs:

// Include Chart.js
echo '<script src="https://cdn.jsdelivr.net/npm/chart.js"></script>';

// Include PHPHistogram library
include_once('PHPCharts.php');

// Establish database connection
$connection = mysqli_connect(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME);   

// Fetch data from MySQL database
$query = "SELECT * FROM your_table";
$data = queryToArray($connection, $query);

// Generate a histogram for a specific field
$histogram = generateHistogram($data, 'your_field_name');
echo $histogram;

// Generate multiple histograms separate by html tab groups based on all fields in the data array:
$multiHistogram = generateMultiHistogram($data, getColumnNames($data));
echo $multiHistogram;

$stackedBarChart = generateStackedBarChart($data, 'x_key', 'y_key', 'stack_key');
echo $stackedBarChart; 

By following these simple steps, you can effortlessly generate dynamic histograms for webpages using PHPHistogram.