Ajax script generator - Easily create starter ajax js and php code - https://www.damiencarbery.com/2018/11/ajax-script-generator/

ajax-code-generator.js

jQuery(document).ready( function( $ ){
	$( '#plugin_php_code' ).html( 'Waiting for PHP code...' );
	$( '#plugin_js_code' ).html( 'Waiting for JavaScript code...' );

	jQuery( '#generate_ajax_code' ).on('click', function( e ) {
	//jQuery( 'header' ).on('click', function( e ) {
		
		e.preventDefault();
		$( '#plugin_php_code' ).html( 'Waiting for PHP code...' );
		$( '#plugin_js_code' ).html( 'Waiting for JavaScript code...' );

        jQuery.ajax({
			url : ajax_code_generator_js_obj.ajax_url, // Note that 'aj_ajax_demo' is from the wp_localize_script() call.
			type : 'post',
			data : {
				action : 'ajax_code_generator_name',  // Note that this is part of the add_action() call.
				submitted_nonce : ajax_code_generator_js_obj.the_nonce,  // Note that 'aj_demo_nonce' is from the wp_localize_script() call.
				script_filename : $( '#script_filename' ).val(),
				ajax_handler_function : $( '#ajax_handler_function' ).val(),
				script_handle : $( '#script_handle' ).val(),
				ajax_handler_name : $( '#ajax_handler_name' ).val(),
				ajax_js_object_name : $( '#ajax_js_object_name' ).val(),

			},
			success : function( response ) {
				console.log( response );
				// Display both pieces of returned data in their respective 'pre' blocks.
				$( '#plugin_php_code' ).html( response.data.ajax_php_code );
				$( '#plugin_js_code' ).html( response.data.ajax_js_code );
			},
			error : function( response ) {
				alert('Error retrieving the information: ' + response.status + ' ' + response.statusText);
				console.log( response );
			}
		});

	});
});

ajax-code-generator.php

<?php
/*
Plugin Name: AJAX Code Generator
Plugin URI: https://www.damiencarbery.com/2018/11/ajax-script-generator/
Description: Ajax code generated by code.
Author: Damien Carbery
Author URI: https://www.damiencarbery.com
Version: 0.1
*/


if ( ! defined( 'ABSPATH' ) ) exit; // Exit if accessed directly


add_shortcode( 'ajax_generator_form', 'dcwd_ajax_generator_form' );
function dcwd_ajax_generator_form() {
	$form = <<< EOF
<form>
<p><label for="script_filename">Script Filename</label><input type="text" name="script_filename" id="script_filename" required="required" value="my_ajax_code.js" /> <span>What is the name of your JS file?</span></p>
<p><label for="ajax_handler_function">Ajax Handler Function</label><input type="text" name="ajax_handler_function" id="ajax_handler_function" required="required" value="my_ajax_function" /> <span>What is the name of the php function that will be called?</span></p>

<p>The following are internal names that you can customise but do not need to.</p>
<p><label for="script_handle">Script Handle</label><input type="text" name="script_handle" id="script_handle" required="required" value="script_handle" /></p>
<p><label for="ajax_handler_name">Ajax Handler Name</label><input type="text" name="ajax_handler_name" id="ajax_handler_name" required="required" value="ajax_handle_name" /></p>
<p><label for="ajax_js_object_name">Ajax Javascript Object Name</label><input type="text" name="ajax_js_object_name" id="ajax_js_object_name" required="required" value="ajax_js_obj" /></p>
</form>
<button id="generate_ajax_code">Generate Code</button>

<pre id="plugin_php_code" class="ajax_code">Waiting for PHP code...</pre>
<pre id="plugin_js_code" class="ajax_code">Waiting for JavaScript code...</pre>
EOF;
	return $form;
}


add_action( 'wp_enqueue_scripts', 'dcwd_admin_enqueue_script' );
function dcwd_admin_enqueue_script() {
	wp_enqueue_script( 'ajax_code_generator', plugin_dir_url( __FILE__ ). 'ajax-code-generator.js', array('jquery') );
	wp_localize_script( 'ajax_code_generator', 'ajax_code_generator_js_obj', array(
                      'ajax_url' => admin_url( 'admin-ajax.php' ),
                      'the_nonce' => wp_create_nonce('MY_NONCE_VAR') 
	));
}


add_action( 'wp_ajax_nopriv_ajax_code_generator_name', 'ajax_code_generator_func' );
add_action( 'wp_ajax_ajax_code_generator_name', 'ajax_code_generator_func' );  // For logged in users.
function ajax_code_generator_func() {
    check_ajax_referer( 'MY_NONCE_VAR', 'submitted_nonce' );  // This function will die if submitted_nonce is not correct.
    
	$script_filename = sanitize_text_field( $_POST[ 'script_filename' ] );
	$ajax_handler_function = sanitize_text_field( $_POST[ 'ajax_handler_function' ] );
	$script_handle = sanitize_text_field( $_POST[ 'script_handle' ] );
	$ajax_handler_name = sanitize_text_field( $_POST[ 'ajax_handler_name' ] );
	$ajax_js_object_name = sanitize_text_field( $_POST[ 'ajax_js_object_name' ] );
	

	$php_code = htmlentities ( "<?php
/*
Plugin Name: Generated AJAX
Plugin URI: http://www.damiencarbery.com
Description: Ajax code generated by code.
Author: The Author
Version: 0.1
*/


if ( ! defined( 'ABSPATH' ) ) exit; // Exit if accessed directly


add_action( 'wp_enqueue_scripts', 'dcwd_ajax_enqueue_script' );
function dcwd_ajax_enqueue_script() {
	wp_enqueue_script( '". $script_handle . "', plugin_dir_url( __FILE__ ). '" . $script_filename . "', array('jquery') );
	wp_localize_script( '" . $script_handle . "', '" . $ajax_js_object_name . "', array(
                      'ajax_url' => admin_url( 'admin-ajax.php' ),
                      'the_nonce' => wp_create_nonce('MY_NONCE_VAR') 
	));
}


add_action( 'wp_ajax_nopriv_" . $ajax_handler_name . "', '" . $ajax_handler_function . "' );
add_action( 'wp_ajax_" . $ajax_handler_name . "', '" . $ajax_handler_function . "' );  // For logged in users.
function " . $ajax_handler_function . "() {
    check_ajax_referer( 'MY_NONCE_VAR', 'submitted_nonce' );  // This function will die if submitted_nonce is not correct.
    
    //\$post_type = sanitize_text_field(\$_POST['post_type']);
		// How to return multiple pieces of data.
		\$response = array( 'first_message' => 'Hello', 'second_message' => 'This is the second message.' );
    wp_send_json_success( \$response );
    
    wp_send_json_error();
    wp_die();
}" );

	$js_code = "jQuery(document).ready( function( $ ){
    jQuery( 'header' ).on( 'click', function(e) {  // Click on the &lt;header&gt; area.
        e.preventDefault();

        jQuery.ajax({
            url : " . $ajax_js_object_name . ".ajax_url,
            type : 'post',
            data : {
                action : '" . $ajax_handler_name . "',  // Note that this is part of the add_action() call.
                submitted_nonce : " . $ajax_js_object_name . ".the_nonce,
                //post_type : post_type
            },
            success : function( response ) {
				// Display both pieces of returned data in different alert boxes.
				alert( response.data.first_message );
				alert( response.data.second_message );
            },
            error : function( response ) {
                alert('Error retrieving the information: ' + response.status + ' ' + response.statusText);
                console.log( response );
            }
        });
    });
});";


	$response = array( 'ajax_php_code' => $php_code, 'ajax_js_code' => $js_code );
	wp_send_json_success( $response );
	
	wp_send_json_error();
	wp_die();
}