Question

I am using this script which is one of the examples provided by jpgraph itself. When I put this on a web-page (blank) by itself, it’s drawing the graph. But when I embed the code in already existing web-page (with some content), it ain’t drawing a graph.

GD is already enabled according to phpinfo(). Iam using jpgraph 3.5.0b1.

Answer 1

The problem is that you are mixing HTML/text output with image output.

Any time you have a PHP script generate graphical content you have to handle the output differently than normal HTML or text.

There are a few routes, I’ll cover them briefly here.

Save the output to a file and use that filename in your HTML

//replace this line:
// Display the graph
//$graph->Stroke();

// with these lines:

    // Default is PNG so use ".png" as suffix
    $fileName = "/tmp/imagefile.png";
    $graph->img->Stream($fileName);

.. then use $filename in an image tag, like this (for example):

print '<img src="'.$filename.'" />';

Create a standalone PHP script that will output the graphic

You can use the example script as-is, alone in a file called graph_render_script.php. Then, in your HTML, you use that script as a source:

<img src="graph_render_script.php" />

Output base-64 encoded data

Another route is to use base-64 encoded image data. This is relatively simple to do:

print '<img src="data:image/png;base64,'.base64_encode($graph->Stroke()).'" />';

As always, the documentation should be your guide!

Documentation

• http://jpgraph.net/download/manuals/chunkhtml/ch05s05.html
• base64_encode – http://php.net/manual/en/function.base64-encode.php