Your first chunk of code is PHP, the second is javascript.
Here is how a full example might look:
In PHP (your theme’s functions.php file or a plugin file):
//First enqueue your javascript in WordPress
function your_prefix_enqueue_scripts(){
//Enqueue your Javascript (this assumes your javascript file is located in your plugin in an "includes/js" directory)
wp_enqueue_script( 'your_unique_js_name', plugins_url('js/yourjavascriptfile.js', dirname(__FILE__) ), array( 'jquery' ) );
//OR (simpler but not recommended)
wp_enqueue_script( 'your_unique_js_name', 'http://domain.com/myjavascriptfile.js', array( 'jquery' ) );
//Here we create a javascript object variable called "youruniquejs_vars". We can access any variable in the array using youruniquejs_vars.name_of_sub_variable
wp_localize_script( 'your_unique_js_name', 'youruniquejs_vars',
array(
//To use this variable in javascript use "youruniquejs_vars.ajaxurl"
'ajaxurl' => admin_url( 'admin-ajax.php' ),
)
);
}
add_action( 'wp_enqueue_scripts', 'your_prefix_enqueue_scripts' );
Then also in PHP, create your ajax callback function:
//This is your Ajax callback function
function your_ajax_callback_function_name(){
//Get the post data
$my_var = $_POST["my_var"];
//Do your stuff here - maybe an update_option as you mentioned...
//Create the array we send back to javascript here
$array_we_send_back = array( 'test' => "Test" );
//Make sure to json encode the output because that's what it is expecting
echo json_encode( $array_we_send_back );
//Make sure you die when finished doing ajax output.
die();
}
add_action( 'wp_ajax_' . 'wpa_49691', 'your_ajax_callback_function_name' );
add_action( 'wp_ajax_nopriv_' . 'wpa_49691', 'your_ajax_callback_function_name' );
And then in your javascript file do something like this:
jQuery(document).ready(function($){
/**
* When your ajax trigger button is clicked
* (if the button's class is .my-button)
*
*/
$( document ).on( 'click', '.my-button', function(event){
event.preventDefault();
// Use ajax to do something...
var postData = {
action: 'wpa_49691',
my_var: 'my_data',
}
//Ajax load more posts
$.ajax({
type: "POST",
data: postData,
dataType:"json",
url: youruniquejs_vars.ajaxurl,
//This fires when the ajax 'comes back' and it is valid json
success: function (response) {
alert( response.test );
}
//This fires when the ajax 'comes back' and it isn't valid json
}).fail(function (data) {
console.log(data);
});
});
});