Solution to Code Challenge 4 from "Refactoring Tweaks Workbook"

code-challenge-4.php

/* Code Challenge 4, from “Refactoring Tweaks Workbook” by Tonya Mork ( 2016, LeanPub (https://leanpub.com/littlegreenbookofrefactoringtweaks-workbook) ). */  

/***************************************************
 *
 * Original code to be refactored.
 *
 **************************************************/
 
class Prefix_Shortcode_Course_Categories implements Prefix_Shortcode_Interface {

	/**
	 * Setup the shortcode object
	 *
	 * @since 1.9.0
	 *
	 * @param array $attributes
	 * @param string $content
	 * @param string $shortcode the shortcode that was called for this instance
	 */
	public function __construct( $attributes, $content, $shortcode ) {
		$this->orderby = isset( $attributes['orderby'] ) ? $attributes['orderby'] : 'name';
		$this->order   = isset( $attributes['order'] ) ? $attributes['order'] : 'ASC';
		$this->number  = isset( $attributes['number'] ) ? $attributes['number'] : '100';
		$this->parent  = isset( $attributes['parent'] ) ? $attributes['parent'] : '';

		$include       = isset( $attributes['include'] ) ? explode( ',', $attributes['include'] ) : '';
		$this->include = $this->generate_term_ids( $include );

		$exclude       = isset( $attributes['exclude'] ) ? explode( ',', $attributes['exclude'] ) : '';
		$this->exclude = $this->generate_term_ids( $exclude );

		// make sure we handle string true/false values correctly with respective defaults
		$hide_empty       = isset( $attributes['hide_empty'] ) ? $attributes['hide_empty'] : 'false';
		$this->hide_empty = 'true' == $hide_empty ? true : false;


		$this->setup_course_categories();
	}
}

/**************************************************
 *
 * Refactored Code
 *
 **************************************************/
class Prefix_Shortcode_Course_Categories implements Prefix_Shortcode_Interface {

	/**
	 * Setup the shortcode object
	 *
	 * @param array  $attributes
	 * @param string $content
	 * @param string $shortcode the shortcode that was called for this instance
	 * @since 1.9.0
	 *
	 */
	public function __construct( $attributes, $content, $shortcode ) {
		$this->orderby  = $this->check_attribute_isset( 'orderby' );
		$this->order    = $this->check_attribute_isset( 'order', 'ASC' );
		$this->number   = $this->check_attribute_isset( 'number', '100' );
		$this->parent   = $this->check_attribute_isset( 'parent' );

		$include       = $this->check_attribute_isset( 'include' );
		$this->include = $this->generate_term_ids( $include );

		$exclude       = $this->check_attribute_isset( 'exclude' );
		$this->exclude = $this->generate_term_ids( $exclude );

		$hide_empty       = $this->check_attribute_isset( 'hide_empty' );
		$this->hide_empty = ( $hide_empty ) ? true : false;

		$this->setup_course_categories();
	}

	protected function check_attribute_isset( $att, $default = '' ) {
		if ( empty( $attributes[ $att ] ) ) {
			return $default;
		}

		if ( is_array( $attributes[ $att ] ) ) {
			return explode( ',', $attributes[ $att ] );
		}

		return $attributes[ $att ];
	}
}