Function to dynamically sync CPT team posts with WP users. The post type requires custom meta fields for linked_author (user ID) and email.

wp-team-post-save-link-user.php

<?php
/**
 * Helper funnction to remove name suffixes.
 *
 * @param  string $name Name.
 * @return array        Suffix-free name parts.
 */
function xx_get_suffix_free_name_parts( $name ) {
	// Format first and last names.
	$parts = explode( ' ', (string) $name );

	// Trim whitespace and punctuation.
	$parts = array_map( function( $part ) {
		return trim( $part, " \t\n\r\0\x0B,.;:'\"[]{}|\\/><()`~!@#$%^&*" );
	}, $parts );

	// Filter out suffixes and one-letter initials.
	$parts = array_filter( $parts, function( $part ) {
		$suffixes = [
			'Jr',
			'Sr',
			'II',
			'III',
			'IV',
			'V',
			'VI',
			'VII',
			'VIII',
			'IX',
			'X',
		];
		return ! ( in_array( $part, $suffixes, true ) || empty( $part ) || strlen( $part ) === 1 );
	} );

	return $parts;
}

/**
 * Create new users to match team members.
 *
 * @param  integer $post_id Post ID.
 */
function xx_team_post_save_link_user( $post_id ) {

	// If not a team post, let's bail.
	if ( 'team' !== get_post_type( $post_id ) ) {
		return;
	}
	
	// Format first and last names.
	$name_parts = xx_get_suffix_free_name_parts( get_the_title( $post_id ) );
	$first_name = $name_parts[0];
	$last_name  = $name_parts[ count( $name_parts ) - 1 ];

	// Get user meta and data.
	$author_id  = get_post_meta( $post_id, 'linked_author', true );
	$user_email = get_post_meta( $post_id, 'email', true );
	
	// Create phony email if the email field isn't set.
	if ( empty( $user_email ) ) {
		$user_email = sanitize_text_field( $first_name ) . sanitize_text_field( $last_name ) . '@enablecomp.com';
	}

	// Check if Linked user is already set.
	if ( $author_id ) {
		$user_meta = get_user_meta( $author_id );
		$user_data = get_userdata( $author_id );

		// If field is set...
		if ( username_exists( $user_data->user_login ) ) {
			// Get the user.
			// Compare fields and data.
			if ( get_the_title( $post_id ) !== $user_data->display_name ) {
				wp_update_user( [
					'ID'           => (int) $author_id,
					'display_name' => sanitize_text_field( get_the_title( $post_id ) ),
				] );
			}
			if ( is_email( $user_email ) ) {
				if ( $user_email !== $user_data->user_email ) {
					wp_update_user( [
						'ID'         => (int) $author_id,
						'user_email' => sanitize_email( $user_email ),
					] );
				}
			}
			if ( $user_meta['first_name'] !== $first_name ) {
				wp_update_user( [
					'ID'         => (int) $author_id,
					'first_name' => sanitize_text_field( $first_name ),
				] );
			}
			if ( $user_meta['last_name'] !== $last_name ) {
				wp_update_user( [
					'ID'        => (int) $author_id,
					'last_name' => sanitize_text_field( $last_name ),
				] );
			}

			return;
		}
	} else { // Look for user with matching email address and link the user if they exist.
		if ( is_email( $user_email ) ) {
			foreach ( get_users() as $user ) {
				if ( $user_email === $user->data->user_email ) {
					update_post_meta( $post_id, 'linked_author', $user->ID );
					break;
					return;
				}
			}
		}
	}

	// If not, let's create a user (author).
	if ( is_email( $user_email ) ) {
		$username = $first_name && $last_name ? strtolower( $first_name ) . '.' . strtolower( preg_replace( '/\s+/', '', $last_name ) ) : strtolower( get_the_title( $post_id ) );
		// For reference, wp_insert_user sanitizes the user login before it is updated in the DB.
		wp_insert_user( [
			'user_login'   => strtolower( $username ),
			'user_pass'    => wp_generate_password(),
			'user_email'   => sanitize_email( $user_email ),
			'display_name' => sanitize_text_field( get_the_title( $post_id ) ),
			'first_name'   => sanitize_text_field( $first_name ),
			'last_name'    => sanitize_text_field( $last_name ),
			'role'         => 'author',
		] );
		// Link the post with the new author.
		update_post_meta( $post_id, 'linked_author', get_user_by( 'email', sanitize_email( $user_email ) )->ID );
	}

	return;
}
add_action( 'save_post', 'xx_team_post_save_link_user' );