Applies tags when a post is viewed based on the names of the categories and post tags assigned to the post

wpf-apply-tags-post-terms.php

<?php

function wpf_apply_tags_on_view( $post ) {

	if( ! function_exists( 'wp_fusion' ) ) {
		return;
	}

	if ( is_admin() || ! is_singular() || ! is_user_logged_in() || $post->post_type != 'post' ) {
		return;
	}

	$tags_to_apply = array();

	$categories = get_the_terms( $post, 'category' );

	if( ! empty( $categories ) && ! is_wp_error( $categories ) ) {

		foreach( $categories as $category ) {

			$tags_to_apply[] = $category->name;

		}

	}

	$tags = get_the_terms( $post, 'post_tag' );

	if( ! empty( $tags ) && ! is_wp_error( $tags ) ) {

		foreach( $tags as $tag ) {

			$tags_to_apply[] = $tag->name;

		}

	}

	wp_fusion()->user->apply_tags( $apply_tags );

}

add_action( 'the_post', 'wpf_apply_tags_on_view' );