<?php

/* Posts */
function ad_column_custom_post_column( $column, $post_id ) 
{
	if ( $column == 'name' ) 
	{
		$p = get_post( $post_id );
		echo esc_attr( $p->post_name );
	} else if ( $column == 'modified' ) {
		echo esc_attr( get_the_date( 'Y-m-d H:i:s', $post_id ) );
	}
}
add_action( 'manage_pages_custom_column' , 'ad_column_custom_post_column', 10, 2 );
add_action( 'manage_posts_custom_column' , 'ad_column_custom_post_column', 10, 2 );

function ad_column_custom_add_post_column($columns) 
{	
	if( is_array($columns) && count($columns) ) {
		$new = array();
		foreach ( $columns as $key => $value ) {
			$new[$key] = $value;
			if( $key == 'title' ) {
				$new['name'] = esc_attr( __( 'Name', 'ad-column-custom' ) );
			}
		}
		
		$columns = $new;
	}
	
	$columns = array_merge( $columns, array( 'modified' => esc_attr( __('Modified') ) ) );
	
	return $columns;
}
add_filter( 'manage_pages_columns' , 'ad_column_custom_add_post_column');
add_filter( 'manage_posts_columns' , 'ad_column_custom_add_post_column');

/* Users */
function ad_column_custom_add_user_id_column($columns) 
{
	if( is_array($columns) && count($columns) ) {
		$new = array();
		foreach ( $columns as $key => $value ) {
			if( $key == 'email' ) 
			{
				$new['display_name'] = esc_attr( __( 'Display Name', 'ad-column-custom' ) );
			}

			$new[$key] = $value;
		}
		
		$columns = $new;
	}
	
	return $columns;
}
add_filter('manage_users_columns', 'ad_column_custom_add_user_id_column');

function ad_column_custom_show_user_id_column_content($value, $column_name, $user_id) 
{
	$user = get_userdata( $user_id );

	if ( $column_name == 'display_name' )
	{
		return esc_attr( $user->display_name );
	}
	else if ( $column_name == 'custom_field' )
	{
		return esc_attr( get_user_meta( $user_id, 'custom_field', true ) );
	}
	
	return $value;
}
add_filter('manage_users_custom_column',  'ad_column_custom_show_user_id_column_content', 10, 3);