JetEngine REST API modify request arguments (e. g. when you need to set more than one header for the request)

rest-api-args.php

<?php

/**
 * Some APIs required more than one header to be sent, 
 * or they need to give out some token first, and only after that to get the actual info
 * Here we show only example with setting additional header, 
 * but you may run some code to do what you need in a specific case
 *
 * Here we have an API, which requires setting not pnly Authorization token (which may be set in REST API endpoiny options)
 * but also a header with the version - that was a real-life example from our user
 * 
 * To add header - add element to $args['headers'], but only when the request goes to a certain API
 * (you may check it by URL)
 * 
 * $request is a Request object, which has the following useful in similar cases methods:
 * get_url() - get the URL to which the request is sent
 * get_endpoint() - to get edpoint settings, which is an array of:
 *    name - endpoint name
 *    url  - endpoint url
 *    other endpoint settings, choosed on its setup
 *
 * Here, get_url() is used to check if the request goes to Notion API
 */
add_filter( 'jet-engine/rest-api-listings/request/args', 'modify_rest_api_args', 0, 2 );

function modify_rest_api_args( $args, $request ) {

	if ( strpos( $request->get_url(), 'api.notion.com' ) !== false ) {
		$args['headers']['Notion-Version'] = '2021-08-16';
	}
  
	return $args;
}