_make_url_clickable_cb() │ WP 2.3.2

Callback to convert URI match to HTML A element.

This function was backported from 2.5.0 to 2.3.2. Regex callback for make_clickable().

Internal function — this function is designed to be used by the kernel itself. It is not recommended to use this function in your code.

No Hooks.

Return

String. HTML A element with URI address.

Usage

_make_url_clickable_cb( $matches );
$matches(array) (required)
Single Regex Match.

Changelog

Since 2.3.2 Introduced.

_make_url_clickable_cb() code WP 6.7.1

wp-includes/formatting.php 
function _make_url_clickable_cb( $matches ) {
	$url = $matches[2];

	if ( ')' === $matches[3] && strpos( $url, '(' ) ) {
		/*
		 * If the trailing character is a closing parenthesis, and the URL has an opening parenthesis in it,
		 * add the closing parenthesis to the URL. Then we can let the parenthesis balancer do its thing below.
		 */
		$url   .= $matches[3];
		$suffix = '';
	} else {
		$suffix = $matches[3];
	}

	if ( isset( $matches[4] ) && ! empty( $matches[4] ) ) {
		$url .= $matches[4];
	}

	// Include parentheses in the URL only if paired.
	while ( substr_count( $url, '(' ) < substr_count( $url, ')' ) ) {
		$suffix = strrchr( $url, ')' ) . $suffix;
		$url    = substr( $url, 0, strrpos( $url, ')' ) );
	}

	$url = esc_url( $url );
	if ( empty( $url ) ) {
		return $matches[0];
	}

	$rel_attr = _make_clickable_rel_attr( $url );

	return $matches[1] . "<a href=\"{$url}\"{$rel_attr}>{$url}</a>" . $suffix;
}