Create custom columns for WordPress Custom Post Types Admin Screen.

CPT_Columns.php

<?php

//Based on Ohad Raz - https://en.bainternet.info/custom-post-types-columns/
//Some info:
//  The classes read the meta field of the CPT ID and enable the sorting
//  Is possible remove other column
//  Support 4 type of object natively: Title, Thumbnail, Custom taxonomy, Custom Field
//  Add a filter cpt_columns_text_{column_name_id} in Title type
//  prefix/suffix values are for all the objects except post_thumb
//  New features by Mte90:
//    Fix for def value
//    New order columns value
//Check the example!

/* Example
  //create an instance
  $post_columns = new CPT_columns('post'); // if you want to replace and reorder columns then pass a second parameter as true
  //add native column
  $post_columns->add_column('title',
  array(
  'label'    => __('Title'),
  'type'     => 'native',
  'sortable' => true
  )
  );
  //add thumbnail column
  $post_columns->add_column('post_thumb',
  array(
  'label' => __('Thumb'),
  'type'  => 'thumb',
  'size'  => array('80,80') //size accepted  by the_post_thumbnail as array or string
  )
  );
  //add taxonomy
  $post_columns->add_column('custom_tax_id',
  array(
  'label'    => __('Custom Taxonomy'),
  'type'     => 'custom_tax',
  'taxonomy' => 'category' //taxonomy name
  )
  );
  //custom field column
  $post_columns->add_column('price',
  array(
  'label'    => __('Custom Field'),
  'type'     => 'post_meta',
  'meta_key' => 'price', //meta_key
  'orderby' => 'meta_value', //meta_value,meta_value_num
  'sortable' => true,
  'prefix' => "$",
  'suffix' => "",
  'def' => "", // default value in case post meta not found
  'order' => "-1" //before the date column
  )
  );
  //remove date column
  $post_columns->remove_column('date');
 */

if ( !class_exists( 'CPT_columns' ) ) {

	/**
	 * CPT_columns 
	 * Simple class to add remove and manage admin post columns 
	 * @author Ohad Raz <[email protected]>
	 * @version 0.1
	 * @copyright 2013 Ohad Raz
	 */
	class CPT_columns {

		/**
		 * $cpt_columns
		 *
		 * holds columns
		 * @var array
		 */
		public $cpt_columns = array();

		/**
		 * $cpt_remove_columns
		 *
		 * holds columns to be removed
		 * @var array
		 */
		public $cpt_remove_columns = array();

		/**
		 * $cpt_sortable_columns
		 *
		 * holds sortable columns
		 * @var array
		 */
		public $cpt_sortable_columns = array();

		/**
		 * $cpt_name 
		 *
		 * Holds custom post type name
		 * @var string
		 */
		public $cpt_name = '';

		/**
		 * $replace 
		 *
		 * Should coulmns be replace (true) or added (false)
		 * @var boolean
		 */
		public $replace = false;

		/**
		 * __construct 
		 * 
		 * @author Ohad Raz <[email protected]>
		 * @since 0.1
		 * @param string  $cpt     custom post type name
		 * @param boolean $replace (optional) replace or add
		 */
		function __construct( $cpt = '', $replace = false ) {
			$this->cpt_name = $cpt;
			$this->replace = $replace;
			//add columns
			add_filter( "manage_{$cpt}_posts_columns", array( $this, '_cpt_columns' ), 50 );
			//remove columns
			add_filter( "manage_{$cpt}_posts_columns", array( $this, '_cpt_columns_remove' ), 60 );
			//display columns
			add_action( "manage_{$cpt}_posts_custom_column", array( $this, '_cpt_custom_column' ), 50, 2 );
			//sortable columns
			add_filter( "manage_edit-{$cpt}_sortable_columns", array( $this, "_sortable_columns" ), 50 );
			//sort order
			add_filter( 'pre_get_posts', array( $this, '_column_orderby' ), 50 );
		}

		/**
		 * _cpt_columns 
		 * 
		 * @author Ohad Raz <[email protected]> & Mte90 <[email protected]>
		 * @since 0.2
		 * @param  array $defaults 
		 * @return array
		 */
		function _cpt_columns( $defaults ) {
			global $typenow;
			if ( $this->cpt_name == $typenow ) {
				$tmp = array();
				if ( $this->replace ) {
					foreach ( $this->cpt_columns as $key => $args ) {
						$tmp[ $key ] = $args[ 'label' ];
					}
					return $tmp;
				} else {
					foreach ( $this->cpt_columns as $key => $args ) {
						$tmp[ $key ] = $args[ 'label' ];
						if ( isset( $args[ 'order' ] ) ) {
							$before = array_slice( $defaults, 0, $args[ 'order' ] );
							$after = array_slice( $defaults, $args[ 'order' ] );
							$return = array_merge( $before, ( array ) $tmp );
							$defaults = array_merge( $return, $after );
						} else {
							$defaults = array_merge( $defaults, $tmp );
						}
						$tmp = '';
					}
				}
			}

			return $defaults;
		}

		/**
		 * _cpt_columns_remove 
		 *
		 * used to remove columns 
		 * @author Ohad Raz <[email protected]>
		 * @since 0.1
		 * @param  array $columns 
		 * @return array         
		 */
		function _cpt_columns_remove( $columns ) {
			foreach ( $this->cpt_remove_columns as $key ) {
				if ( isset( $columns[ $key ] ) ) {
					unset( $columns[ $key ] );
				}
			}
			return $columns;
		}

		/**
		 * _sortable_columns 
		 *
		 * sets sortable columns
		 * @author Ohad Raz <[email protected]>
		 * @since 0.1
		 * @param  array $columns 
		 * @return array
		 */
		function _sortable_columns( $columns ) {
			global $typenow;
			if ( $this->cpt_name == $typenow ) {
				foreach ( $this->cpt_sortable_columns as $key => $args ) {
					$columns[ $key ] = $key;
				}
			}
			return $columns;
		}

		/**
		 * _cpt_custom_column
		 *
		 * calls do_column() when the column is set
		 * @author Ohad Raz <[email protected]>
		 * @since 0.1
		 * @param  string $column_name column name
		 * @param  int $post_id     post ID
		 * @return void
		 */
		function _cpt_custom_column( $column_name, $post_id ) {
			if ( isset( $this->cpt_columns[ $column_name ] ) ) {
				$this->do_column( $post_id, $this->cpt_columns[ $column_name ], $column_name );
			}
		}

		/**
		 * do_column
		 *
		 * used to display the column
		 * @author Ohad Raz <[email protected]>
		 * @since 0.1
		 * @param  int $post_id     	post ID
		 * @param  array $column      	column args
		 * @param  string $column_name 	column name
		 * @return void
		 */
		function do_column( $post_id, $column, $column_name ) {
			if ( in_array( $column[ 'type' ], array( 'text', 'thumb', 'post_meta', 'custom_tax' ) ) ) {
				echo $column[ 'prefix' ];
			}
			switch ( $column[ 'type' ] ) {
				case 'text':
					echo apply_filters( 'cpt_columns_text_' . $column_name, $column[ 'text' ], $post_id, $column, $column_name );
					break;
				case 'thumb':
					if ( has_post_thumbnail( $post_id ) ) {
						the_post_thumbnail( $column[ 'size' ] );
					} else {
						echo 'N/A';
					}
					break;
				case 'post_meta':
					$tmp = get_post_meta( $post_id, $column[ 'meta_key' ], true );
					echo (!empty( $tmp )) ? $tmp : $column[ 'def' ];
					break;
				case 'custom_tax':
					$post_type = get_post_type( $post_id );
					$terms = get_the_terms( $post_id, $column[ 'taxonomy' ] );
					if ( !empty( $terms ) ) {
						foreach ( $terms as $term ) {
							$href = "edit.php?post_type={$post_type}&{$column[ 'taxonomy' ]}={$term->slug}";
							$name = esc_html( sanitize_term_field( 'name', $term->name, $term->term_id, $column[ 'taxonomy' ], 'edit' ) );
							$post_terms[] = "<a href='{$href}'>{$name}</a>";
						}
						echo join( ', ', $post_terms );
					} else {
						echo '';
					}
					break;
			}//end switch
			if ( in_array( $column[ 'type' ], array( 'text', 'thumb', 'post_meta', 'custom_tax' ) ) ) {
				echo $column[ 'suffix' ];
			}
		}

		/**
		 * _column_orderby 
		 *
		 * used to roder by meta keys
		 * @author Ohad Raz <[email protected]>
		 * @since 0.1
		 * @param  object $query 
		 * @return void
		 */
		function _column_orderby( $query ) {
			if ( !is_admin() ) {
				return;
			}

			$orderby = $query->get( 'orderby' );
			$keys = array_keys( ( array ) $this->cpt_sortable_columns );
			if ( in_array( $orderby, $keys ) ) {
				//order by meta
				if ( 'post_meta' == $this->cpt_sortable_columns[ $orderby ][ 'type' ] ) {
					$query->set( 'meta_key', $orderby );
					$query->set( 'orderby', $this->cpt_sortable_columns[ $orderby ][ 'orderby' ] );
				}
			}
		}

		/**
		 * add_column
		 *
		 * used to add column
		 * @author Ohad Raz <[email protected]>
		 * @since 0.1
		 * @param string $key column id
		 * @param array $args column arguments
		 * @return void
		 */
		function add_column( $key, $args ) {
			$def = array(
				'label' => 'column label',
				'size' => array( '80', '80' ),
				'taxonomy' => '',
				'meta_key' => '',
				'sortable' => false,
				'text' => '',
				'type' => 'native', //'native','post_meta','custom_tax',text
				'orderby' => 'meta_value',
				'prefix' => '',
				'suffix' => '',
				'def' => '',
			);
			$this->cpt_columns[ $key ] = array_merge( $def, $args );

			if ( $this->cpt_columns[ $key ][ 'sortable' ] ) {
				$this->cpt_sortable_columns[ $key ] = $this->cpt_columns[ $key ];
			}
		}

		/**
		 * remove_column 
		 *
		 * Used to remove columns
		 * 
		 * @author Ohad Raz <[email protected]>
		 * @since 0.1
		 * @param  string $key column key to be removed
		 * @return void
		 */
		function remove_column( $key ) {
			$this->cpt_remove_columns[] = $key;
		}

	}

}