Home/ Questions/Q 3312764
In Process

The Archive Base Latest Questions

Editorial Team
  • 0
Asked: 2026-05-17T22:02:03+00:00

I’m creating a graph that does some database queries then builds the graph using

  • 0

I’m creating a graph that does some database queries then builds the graph using GD functions then also puts the info from the database into an array that is stored in $_SESSION[‘my_data’]. This graph is displayed on the web page using img tags.

<img src="my_graph.php?time=$time">

<?
    print_r($_SESSION['my_data']);
?>

The problem is when I print_r() the array from the session variable it doesn’t print the current graphs data; it prints the data that was in the graph last time the page was loaded. It’s acting like a cookie.

I have tried putting session_write_close() immediately after I store the array in the session because I thought $_SESSION might have been locked until my_graph.php finished loading the image. That did not work.

I also tried putting sleep(10) before I print the array and that did not work.

Why this would happen?

Share

Leave an answer

You must login to add an answer.

Need An Account,

1 Answer

  1. Editorial Team

    I suppose, when your web server executes PHP code, which draws our page, it already has $_SESSION array initialized. And this array is not updated in current script runtime. When browser finds image tag, it makes another request to web server, which executes image generation script, which updates $_SESSION array in another runtime.

    You may:

    • either make all calculations in your web page generation code
    • or reload page after image generation script completes calculations and sets all necessary data in $_SESSION array
    • 0