Custom API Development of outside the usual WordPress custom post type data fetching

To create an API for a custom post type taxonomy in WordPress using wp-load.php, you can create a standalone PHP script that loads the WordPress environment and fetches the taxonomy terms. This is particularly useful if you need to create a custom API outside the usual WordPress REST API structure or for custom data fetching.

Step 1: Create the PHP File

Create a new file called custom-api.php and place it in the root of your WordPress installation or a suitable directory.

Step 2: Add Code to Load WordPress Environment and Fetch Data

Add the following code to custom-api.php:

<?php

header('Access-Control-Allow-Origin: *');
header('Access-Control-Allow-Methods: POST, GET');
  
$path = dirname(__DIR__, 3);
$wp_load = $path.'\wp-load.php'; 
 
require($wp_load); 

if(isset($_POST['state_slug'])){
    
    $slug = $_POST['state_slug']; 
    $result =  array(); 

        $args = array( 'post_type' => 'taxonomy_name', 'taxonomy_name'=> 'category_name');
    
        $the_query = new WP_Query( $args ); ?>
 

        <?php while ( $the_query->have_posts() ) : $the_query->the_post(); ?>
        
            <?php 
                
                $result[] = array(
                    'title' => get_the_title(), 
                    'content' => get_the_content(), 
                    );

                ?>

            <?php endwhile;

                wp_reset_postdata(); ?>
  
            <?php
            // Encode the data to JSON format and output it
            
                $response = array(
                    'result' => 'Success',
                    'data' => $result
                );
    
                header('Content-type: application/json; charset=utf-8');
                echo json_encode($response);
                ?>

            <?php
                }
            ?>        

Step 3: Access the API

Access the script in your browser or via an HTTP request:

http://localhost/myfreeonlinetools/wp-content/themes/myfreeonlinetools-blog/custom-api.php