Count / Save / Add Wordcount Column to Pages

word_count_column.php

<?php
/**
 * Plugin Name: Word Count Tracker
 * Description: Simply saves the word count with the post.
 * Version: 1.0.0
 */

if( ! defined( 'ABSPATH' ) ) {
	die( 'There was a HOLE here. It\'s gone now.' );
}


/**
 * Count number of words in a given string
 * @link http://php.net/manual/en/function.str-word-count.php#107363
 *
 * @param String $str - The given string of content
 *
 * @return Integer $count - Number of counted words in given string
 */
function wpse_wct_word_count( $str ) {
	
	$count = 0;
	
	if( ! empty( $str ) ) {
		
		$content 	= strip_tags( $str );	// Strip any HTML so they're not counted
		$word_arr	= array_filter( preg_split( '~[^\p{L}\p{N}\']+~u', $content ) );	// Retrieve an array of words based on our content
		$count		= count( $word_arr );	// Count items in array
		
	}
	
	
	/**
	 * Allow modification of count variable
	 * 
	 * @param Integer $count 	- Number of words expected to be returned
	 * @param String $str 		- Unmodified given user string
	 *
	 * @return $count
	 */
	$count = apply_filters( 'wpse_wct_count_modify', $count, $str );
	
	return intval( $count );
	
}


/**
 * Get acceptable post types
 *
 * @return Array $types - Array of WordPress post types
 */
function wpse_wct_get_post_types() {
	
	/**
	 * Allow modification of acceptable post types
	 *
	 * @param Array of default post types
	 *
	 * @return Array of acceptable post types
	 */
	return apply_filters( 'wpse_wct_accepted_post_types', array( 'post', 'page' ) );
	
}


/**
 * Save word count as postmeta '_wct_word_count'
 *
 * @param Integer $post_id 	- The saved Post ID
 * @param WP_Post $post 	- The saved WP_Post Object
 *
 * @return void
 */
function wpse_wct_save_post( $post_id, $post ) {
	
	// If we're not in the right place, bailout
	if( ! is_object( $post ) || wp_is_post_autosave( $post ) || wp_is_post_revision( $post ) ) {
		return $post_id;
	}
	
	// Get Acceptable post types
	$acceptable_post_types = wpse_wct_get_post_types();
	
	// If this post is of an acceptable type
	if( ! empty( $acceptable_post_types ) && in_array( $post->post_type, $acceptable_post_types ) ) {
		
		update_post_meta( $post->ID, '_wct_word_count', wpse_wct_word_count( $post->post_content ) );
		
	}
	
}
add_action( 'save_post', 'wpse_wct_save_post', 10, 2 );


/**
 * Admin Initialization - setup admin hooks
 *
 * @return void
 */
function wpse_wct_admin_hooks() {
	
	// Get Acceptable post types
	$acceptable_post_types = wpse_wct_get_post_types();
	
	// Ensure we have an workable array
	if( ! empty( $acceptable_post_types ) ) {
		
		// Loop through array of post types and assign hooks
		foreach( $acceptable_post_types as $post_type ) {
			
			// Add in new word count column
			add_filter( "manage_edit-{$post_type}_columns", 'wpse_wct_word_count_col' );
			
			// Display post word count
			add_action( "manage_{$post_type}_posts_custom_column", 'wpse_wct_word_count_col_display', 10, 2 );
			
			// Allow word count column to be sortable
			add_filter( "manage_edit-{$post_type}_sortable_columns", 'wpse_wct_word_count_col_sort' );
			
		}
		
	}
	
}
add_action( 'admin_init', 'wpse_wct_admin_hooks' );


/**
 * Add the new word count column
 *
 * @hook_added wpse_wct_admin_hooks()
 *
 * @param Array $cols - Array of columns : array( 'col-slug', 'Column Name' )
 *
 * @return Array $cols
 */
function wpse_wct_word_count_col( $cols ) {
	
	$cols['wct-count'] = __( 'Word Count' );
	
	return $cols;
	
}


/**
 * Display the post word count
 *
 * @hook_added wpse_wct_admin_hooks()
 *
 * @param String $col_name - The current columns name
 * @param Integer $post_id - The current Post ID
 *
 * @return void
 */
function wpse_wct_word_count_col_display( $col_name, $post_id ) {
	
	$post = get_post( $post_id );
	
	// Ensure we're displaying the correct column
	if( is_object( $post ) && 'wct-count' === $col_name ) {
		
		$count = get_post_meta( $post_id, '_wct_word_count', true );	// Get word count
		
		// Check if the count exists
		if( empty( $count ) && ! empty( $post->post_content ) ) { 		// Doesn't exist
			
			$count = wpse_wct_word_count( $post->post_content );		// Get word count
			update_post_meta( $post_id, '_wct_word_count', $count );	// Set word count
			
		}
		
		// Display word count
		printf( _n( '%1$s word', '%1$s words', $count ), number_format( $count ) );
		
	}
	
}


/**
 * Allow WordPress to sort on the column
 *
 * @hook_added Function wpse_wct_admin_hooks()
 *
 * @param Array $cols - Sortable admin columns
 *
 * @return Array $cols - Sortable admin columns
 */
function wpse_wct_word_count_col_sort( $cols ) {
	
	// Append columns
	$cols['wct-count'] = 'word_count';
	
	return $cols;
	
}


/**
 * Set sortable query
 *
 * @param WP_Query Object $query - Current admin WP_Query
 *
 * @return void
 */
function wpse_wct_pre_get_posts( $query ) {
	
	// Only run on the admin side
	if( ! is_admin() ) {
		return;
	}
	
	// Ensure we have our sortable var set
	if( 'word_count' !== $query->get( 'orderby' ) ) {
		return;
	}
	
	// Get Acceptable post types
	$acceptable_post_types = wpse_wct_get_post_types();
	
	// Get current post type
	$current_post_type = $query->get( 'post_type' );
	
	// Ensure this post type is an acceptable one
	if( ! empty( $acceptable_post_types ) && in_array( $current_post_type, $acceptable_post_types ) ) {
		$query->set( 'meta_key', '_wct_word_count' );	// Set metakey
		$query->set( 'orderby', 'meta_value_num' );		// Order by meta value as a number
	}
	
}
add_action( 'pre_get_posts', 'wpse_wct_pre_get_posts' );


/**
 * Change custom admin column width
 * Ugh...
 *
 * @retun void
 */
function wpse_wct_admin_col_styles() {
	
  ?>
  
	<style>
		.column-wct-count	{}
	</style>
	
  <?php
	
}
add_action( 'admin_head', 'wpse_wct_admin_col_styles' );