Get the value of an ECF field for a comment

ecf_get_field_value.php

<?php
/**
 * Get the value of an Extra Comment Field.
 * @param string $ref The ref code of the field to retrieve e.g. 'ecf_3'.
 * @param integer $comment_id The id of the comment.
 * @return string|null The value of the user's response to the field.
 * @see ecfdb::get_comment_data()
 */
function ecf_get_field_value( $ref, $comment_id = null ) {
	// Make use of the global variable containing the Extra Comment Fields 
	// database and WordPress comment objects
	global $ecfdb, $comment;

	// If no comment id has been specified, use the id of the current comment
	if (is_null($comment_id)) $comment_id = $comment->ID;

	// Retrieve the Extra Comment Fields data from the comment metadata
	$comment_data = $ecfdb->get_comment_data($comment_id);

	// Retrieve the data for the current field, if found, otherwise null
	return isset($comment_data[$ref]) ? $comment_data[$ref] : null;
}

// Get the value of field ecf_3 for the current comment
$a = ecf_get_field_value( 'ecf_3' );

// Get the value of field ecf_3 for comment id 4
$b = ecf_get_field_value( 'ecf_3', 4 );