How to pass php variable to wordpress AJAX handler - php

Question

Struggling to pass through some php variables into my ajax handler function in functions.php
Example provided below doesn't work, probably has something to do with the hooks but I can't find any info on how to do this:
/*Unsubscribe*/
$test_variable = "derp";
function user_unsubscribe($test_variable){
echo json_encode($test_variable);
wp_die();
};
add_action('wp_ajax_user_unsubscribe', 'user_unsubscribe');
add_action('wp_ajax_nopriv_user_unsubscribe', 'user_unsubscribe');

Answer 1

Solved it with this solution: can I pass arguments to my function through add_action?
Working code solution is:
/*Unsubscribe*/
$test_variable = "derp";
function user_unsubscribe($test_variable){
echo json_encode($test_variable);
wp_die();
};
add_action('wp_ajax_user_unsubscribe', function() use ($test_variable){
user_unsubscribe($test_variable);
});
add_action('wp_ajax_nopriv_user_unsubscribe', function() use ($test_variable){
user_unsubscribe($test_variable);
});

Answer 2

You can pass that PHP variable in ajax data. Please check below files in which I had send the "test_variable" Value to Ajax Function from jQuery.
Jquery File Code
jQuery(document).ready(function($) {
$('#btn').on('click',function(){
$.ajax({
data: {action: 'get_listing_names','test': global.test_variable},
type: 'post',
url: global.ajax,
success: function(data) {
console.log(data);
}
});
});
});
Functions.php file Code.
<?php
/**
* Enqueue scripts and styles.
*
* #since 1.0.0
*/
function ja_global_enqueues() {
wp_enqueue_script(
'global',
get_template_directory_uri() . '/js/global.js',
array( 'jquery' ),
'1.0.0',
true
);
wp_localize_script(
'global',
'global',
array(
'ajax' => admin_url( 'admin-ajax.php' ),
'test_variable' => 'Test Value',
)
);
}
add_action( 'wp_enqueue_scripts', 'ja_global_enqueues' );
add_action('wp_ajax_nopriv_get_listing_names', 'ajax_listings');
add_action('wp_ajax_get_listing_names', 'ajax_listings');
function ajax_listings() {
$test_variable = $_POST['test_variable'];
wp_send_json_success( $test_variable );
}

Answer 3

The prefered way to pass variables to ajax is to add them to the request and read them from $_GET or $_POST official documentation
If you need other variables you'll either have to use globals or call a extra function.
favorite
Struggling to pass through some php variables into my ajax handler function in functions.php
Example provided below doesn't work, probably has something to do with the hooks but I can't find any info on how to do this:
function user_unsubscribe(){
$test_variable = get_test_variable();
echo json_encode($test_variable);
wp_die();
};
add_action('wp_ajax_user_unsubscribe', 'user_unsubscribe');
add_action('wp_ajax_nopriv_user_unsubscribe', 'user_unsubscribe');
function get_test_variable() {
// here get/fetch your variable;
/*Unsubscribe*/
$test_variable = "derp";
return $test_variable;
}