Solution to Code Challenge 6 from "Refactoring Tweaks Workbook"

code-challenge-6.php

/* Code Challenge 6, from “Refactoring Tweaks Workbook” by Tonya Mork ( 2016, LeanPub (https://leanpub.com/littlegreenbookofrefactoringtweaks-workbook) ). */  

/***************************************************
 *
 * Original code to be refactored.
 *
 **************************************************/
 

/**
 * Return the special URL of a paged post.
 *
 * Taken from _wp_link_page() in WordPress core, but instead of anchor markup, just return the URL.
 *
 * @since 2.2.0
 *
 * @param int $i The page number to generate the URL from.
 * @param int $post_id The post ID
 *
 * @return string Unescaped URL
 */
function prefix_paged_post_url( $i, $post_id = 0 ) {

	global $wp_rewrite;

	$post = get_post( $post_id );

	if ( 1 == $i ) {
		$url = get_permalink( $post_id );
	} else {
		if ( '' == get_option( 'permalink_structure' ) || in_array( $post->post_status, array( 'draft', 'pending' ) ) ) {
			$url = add_query_arg( 'page', $i, get_permalink( $post_id ) );
		} elseif ( 'page' == get_option( 'show_on_front' ) && get_option( 'page_on_front' ) == $post->ID ) {
			$url = trailingslashit( get_permalink( $post_id ) ) . user_trailingslashit( "$wp_rewrite->pagination_base/" . $i, 'single_paged' );
		} else {
			$url = trailingslashit( get_permalink( $post_id ) ) . user_trailingslashit( $i, 'single_paged' );
		}
	}

	return $url;

}

/***************************************************
 *
 * Refactored Code
 *
 **************************************************/
 
 /**
 * Return the special URL of a paged post.
 *
 * Taken from _wp_link_page() in WordPress core, but instead of anchor markup, just return the URL.
 *
 * @since 2.2.0
 *
 * @param int $page_number The page number to generate the URL from.
 * @param int $post_id The post ID
 *
 * @return string Unescaped URL
 */
function prefix_paged_post_url( $page_number, $post_id = 0 ) {
	$post = get_post( $post_id );
	
	if ( 1 == $page_number ) {
		$url = get_permalink( $post_id );
	} else {
		url_when_page_number_does_not_equal_one( $page_number, $post_id );
	}

	return $url;
}

/*
 * Decision logic to get permalink when $page_number is not equal to 1. 
 */
function url_when_page_number_does_not_equal_one( $page_number, $post_id ) {
	$wp_rewrite = new \WP_Rewrite();
  
	if ( '' == get_option( 'permalink_structure' ) || in_array( $post->post_status, array( 'draft', 'pending' ) ) ) {
		$url = add_query_arg( 'page', $page_number, get_permalink( $post_id ) );
	} elseif ( 'page' == get_option( 'show_on_front' ) && get_option( 'page_on_front' ) == $post->ID ) {
		$url = trailingslashit( get_permalink( $post_id ) ) . user_trailingslashit( "$wp_rewrite->pagination_base/" . $page_number, 'single_paged' );
	} else {
		$url = trailingslashit( get_permalink( $post_id ) ) . user_trailingslashit( $i, 'single_paged' );
	}
}