transient_slider.php

<div u="slides" style="cursor: move; position: absolute; overflow: hidden; left: 0px; top: 0px; width: 1090px; height: 550px;">
	<?php
	$slides_trans = get_transient( "slides_rest_api");
	$allslides = array();
	if( !$slides_trans || $_REQUEST['reset_trans'] == 'please' ) {
		// Best to use wp_remote_get here but for brevity in example we use file_get_contents
		$callret = file_get_contents( site_url() . '/wp-json/posts?filter[category_name]=home-slides&filter[posts_per_page]=-1' );
		$allslides = json_decode( $callret, true );
		set_transient( "slides_rest_api", $callret, 60*60*12 );
	} else {
		$allslides = json_decode( $slides_trans, true );
	}

	$cnt = 0;
	foreach ($allslides as $slide) {
		$thumbnail_id = get_post_thumbnail_id($slide['ID']);
		$thumbnail = wp_get_attachment_image_src($thumbnail_id, 'large');

		?>
		<div data-idle="6500">
		<a href="<?php echo esc_url( $slide['link'] ); ?>"><img u="image" src='<?php echo $thumbnail[0]; ?>' /></a>
		</div>
		<?php
		$cnt++;
	}
	?>
</div>