Passing ajax variable to more than one wordpress plugin function

Question

I'm trying to get information from the front end of my Wordpress site, I used ajax to do that, it gave me the ability to use the data in one of my plugin functions, but in my case I want to use this data in more than just one function.

add_action( 'admin_footer', 'my_action_javascript' ); 

function my_action_javascript() { ?>
    <script type="text/javascript" >
    jQuery(document).ready(function($) {

        var data = {
            'action': 'my_action',
            'whatever': 1234
        };

        jQuery.post(ajaxurl, data);
    });
    </script> <?php
}

add_action( 'wp_ajax_my_action', 'my_action' );

function my_action() {

    $whatever = $_POST['whatever'];

}

In other words I need to use $_POST['whatever'] in other functions in my plugin not only my_action() function, I tried using PHP global variables like so , but it didn't workout:

$whatever;
function my_action(){
    global $whatever = $_POST['whatever'];
}
function my_other_function(){
   global $whatever;
   if(isset($whatever)){
       echo $whatever;
   }
}

Answer 1

If you want to use a global variable, you have to set it outside any local scope, above your functions. For example:

if (isset($_POST['whatever'])) {
    $variable = $_POST['whatever'];
}

This will store it in the superglobal array. Now, access it using the $_GLOBALS array:

function my_action(){
   $whatever = $GLOBALS['variable'];
}

I would however have an easier approach. You can get the variable in one function and call the other one inside it. Take a look at this:

function first_func(){
    $variable = $_POST['whatever'];
    // Do whatever you want here
    echo "First $variable";
    // Now call the second one
    second_func($variable);
}
function second_func($input){
    echo $input;
}

Avoiding the globals is a good practice since you don't know what else could interfere with the array.