Class which will retrieve custom fields when passed an array of field names.

Meta.php

<?php
/**
 * Simple class designed to return
 * multiple custom fields.
 *
 * This is a simple class which will
 * return custom fields in the format
 * $this->field_name when passed an
 * array of custom field names.
 *
 * @author Craig Simpson
 * @package
 * @since 1.0
 */

class Retrieve_Meta {

	protected $post_id;

	/**
	 * Retrieve_Meta constructor.
	 *
	 * @param array $fields Array of field names to be assigned and retrieved.
	 * @param int $post_id Post id to be used for lookup, defaults to $post->ID.
	 */
	public function __construct( array $fields, $post_id = 0) {

		$this->get_meta( $fields );

	}

	/**
	 * Function assigns field name and corresponding value to $this->field.
	 *
	 * @param array $fields Array of field names to be assigned and retrieved.
	 * @param int $post_id Post ID to be used for lookup, defaults to $post->ID.
	 */
	protected function get_meta( array $fields, $post_id = 0 ) {

		global $post;

		$this->post_id = $post_id > 0 ? $post_id : $post->ID;

		foreach( $fields as $field ) {
				$this->$field = get_post_meta( $this->post_id, $field, true );
		}

	}

}