Creating custom REST endpoints in #WordPress (Custom API)

functions.php

<?php

add_action('rest_api_init', 'register_rest_routes' );

function register_rest_routes(){
  // URL will be /wp-json/custom-route/v1/add-list
  register_rest_route( 'custom-route/v1', 'add-list',array(
    'methods'  => 'POST',
    'callback' => array('Custom_InfusionWP', 'add_list'),
    'permission_callback' => function() {
      return current_user_can('edit_posts'); // Can just return true if it's a public endpoint
    }
  ));
}

function add_to_list($response){
  write_log('From our API call');
  //write_log($_POST);
  write_log( $response->get_json_params() ); // If payload is sent as a JSON body, this is how you access
  
  wp_send_json_success( $_POST );
}

// Alt method
add_action( 'wp_ajax_add_to_list', array( $this, 'add_to_list' ) );
add_action( 'wp_ajax_nopriv_add_to_list', array( $this, 'add_to_list' ) );

snippet.js

// How to pass user nonce through PHP

async search( searchTerm ) {
  let data = {
    "searchTerm": "foo",
  };

  // Ref: https://developer.mozilla.org/en-US/docs/Web/API/Fetch_API/Using_Fetch
  // Ref 2: https://stackoverflow.com/a/43263012
  let results = await fetch(this.apiUrl + 'search-orgs', {
    method: "POST", // *GET, POST, PUT, DELETE, etc.
    mode: "cors", // no-cors, *cors, same-origin
    cache: "no-cache", // *default, no-cache, reload, force-cache, only-if-cached
    credentials: "same-origin", // include, *same-origin, omit
    headers: {
      "Content-Type": "application/json",
      // 'Content-Type': 'application/x-www-form-urlencoded',
      "X-WP-Nonce": "<?php echo wp_create_nonce('wp_rest'); ?>",
    },
    redirect: "follow", // manual, *follow, error
    referrerPolicy: "no-referrer", // no-referrer, *no-referrer-when-downgrade, origin, origin-when-cross-origin, same-origin, strict-origin, strict-origin-when-cross-origin, unsafe-url
    body: JSON.stringify(data), // body data type must match "Content-Type" header
  });

},