Custom block shortcode template

Wouldn’t it be nice to have the option to output custom HTML when using shortcodes? Based on the possibility to change the widget layout I’d suggest to enhance post-widget.php like in the following:

function custom_post_widget_shortcode( $atts ) {
	extract( shortcode_atts( array(
		'id' => '',
		'slug' => '',
		'class' => 'content_block',
		'suppress_content_filters' => 'no',
		'title' => 'no',
		'title_tag' => 'h3'
	), $atts ) );

	if ( $slug ) {
		$block = get_page_by_path( $slug, OBJECT, 'content_block' );
		if ( $block ) {
			$id = $block->ID;
		}
	}

	$content = "";

	if( $id != "" ) {
		$args = array(
			'post__in' => array( $id ),
			'post_type' => 'content_block',
		);

		$content_post = get_posts( $args );

		if ( $located = locate_template( 'custom-post-shortcode.php' ) ) {
			require $located;
			return;
		}

		foreach( $content_post as $post ) :
			$content .= '<div class="'. esc_attr($class) .'" id="custom_post_widget-' . $id . '">';
			if ( $title === 'yes' ) {
				$content .= '<' . esc_attr( $title_tag ) . '>' . $post->post_title . '</' . esc_attr( $title_tag ) . '>';
			}
			if ( $suppress_content_filters === 'no' ) {
				$content .= apply_filters( 'the_content', $post->post_content);
			} else {
				$content .= $post->post_content;
			}
			$content .= '</div>';
		endforeach;
	}

	return $content;
}
add_shortcode( 'content_block', 'custom_post_widget_shortcode' );

A custom shortcode template:

<?php

foreach( $content_post as $post ) :
    $content .= '<div class="'. esc_attr($class) .'" id="custom_post_widget-' . $id . '">';
    if ( $title === 'yes' ) {
        $content .= '<' . esc_attr( $title_tag ) . '>' . $post->post_title . '</' . esc_attr( $title_tag ) . '>';
    }
    if ( $suppress_content_filters === 'no' ) {
        $content .= apply_filters( 'the_content', $post->post_content);
    } else {
        $content .= $post->post_content;
    }
    $content .= '</div>';
endforeach;

echo $content

?>