WordPress transients example

WordPress transient example

<?php
/**
 * Get a list of email subscribers.
 *
 * @return object The HTTP response that comes as a result of a wp_remote_get().
 */
function css_t_subscribers() {

  // Do we have this information in our transients already?
  $transient = get_transient( 'css_t_subscribers' );
  
  // Yep!  Just return it and we're done.
  if( ! empty( $transient ) ) {
    
    // The function will return here every time after the first time it is run, until the transient expires.
    return $transient;

  // Nope!  We gotta make a call.
  } else {
  
    // We got this url from the documentation for the remote API.
    $url = 'https://api.example.com/v4/subscribers';
    
    // We are structuring these args based on the API docs as well.
    $args = array(
      'headers' => array(
        'token' => 'example_token'
      ),
    );
    
    // Call the API.
    $out = wp_remote_get( $url, $args );
    
    // Save the API response so we don't have to call again until tomorrow.
    set_transient( 'css_t_subscribers', $out, DAY_IN_SECONDS );
    
    // Return the list of subscribers.  The function will return here the first time it is run, and then once again, each time the transient expires.
    return $out;
    
  }
  
}