simple-new-post-emails.php

<?php
/**
 * Plugin Name:       Simple New Post Emails
 * Plugin URI:        https://github.com/10up/simple-new-post-emails
 * Description:       Allow site members to check a box and get new posts via email. Includes a widget.
 * Version:           0.7.1
 * Requires at least: 3.0
 * Requires PHP:
 * Author:            10up
 * Author URI:        https://10up.com
 * License:           GPL v2 or later
 * License URI:       https://www.gnu.org/licenses/gpl-2.0.html
 */

/*
Copyright 2013 10up

This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.

This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
*/

class Simple_New_Post_Emails {
	/**
	 * Set up hooks.
	 */
	public function __construct() {
		require_once( 'inc/widget-snpe.php' );

		add_action( 'widgets_init', array( $this, 'widgets_init' ) );
		add_action( 'personal_options', array( $this, 'personal_options' ) );
		add_action( 'edit_user_profile_update', array( $this, 'option_save' ) );
		add_action( 'personal_options_update', array( $this, 'option_save' ) );
		add_action( 'wp_ajax_snpe-options-save', array( $this, 'ajax_option_save' ) );
		add_action( 'publish_post', array( $this, 'publish_post' ), 10, 2 );
		add_filter( 'manage_users_columns', array( $this, 'add_snpe_user_column') );
		add_action( 'manage_users_custom_column', array( $this, 'show_snpe_user_column_content'), 10, 3 );
	}

	/**
	 * Register the widget.
	 * @return null
	 */
	public function widgets_init() {
		register_widget( 'SNPE_Widget' );
	}

	/**
	 * Add the setting to the user profile page.
	 * @param  WP_User $user User object.
	 * @return null
	 */
	public function personal_options( $user ) {
?>
<tr class="snpe-option">
	<th scope="row">New Post Emails</th>
	<td>
		<label for="snpe_send">
			<input name="snpe_send" type="checkbox" id="snpe_send" value="Y"<?php checked( $user->snpe_send, 'Y' ); ?> />
			Email me when a new post is published
		</label>
	</td>
</tr>
<?php
	}

	/**
	 * Save our custom profile option.
	 * @param  int $user_id User ID
	 * @return bool         Whether or not the option was successfully saved.
	 */
	public function option_save( $user_id ) {
		if ( ! current_user_can( 'edit_user', $user_id ) ) {
			return false;
		}

		if ( isset( $_POST['snpe_send'] ) && 'Y' === $_POST['snpe_send'] ) {
			return update_user_meta( $user_id, 'snpe_send', 'Y' );
		} else {
			return delete_user_meta( $user_id, 'snpe_send' );
		}
	}

	/**
	 * Save our profile option on Ajax.
	 * @return null
	 */
	public function ajax_option_save() {
		check_admin_referer( 'snpe-options-save' );

		$user = wp_get_current_user();
		if ( ! $this->option_save( $user->ID ) ) {
			wp_send_json_error();
		}

		$data = isset( $_POST['snpe_send'] ) ? true : false;
		wp_send_json_success( $data );
	}

	/**
	 * Fire off emails if this is the first publish.
	 * @param  int     $post_id Post ID.
	 * @param  WP_Post $post    Post object.
	 * @return null
	 */
	public function publish_post( $post_id, $post ) {
		// We've already sent an email for this before, so bail.
		if ( 'Y' === get_post_meta( $post_id, 'snpe_sent', true ) ) {
			return;
		}

		$sent = false;

		// Note: we do not escape anything in the subject line, allowing PHPMailer to handle.
		$subject = '[' . get_bloginfo( 'name' ) . '] ' . $post->post_title;

		$message = '<html><body>';
		$message .= '<h3><a href="' . get_permalink( $post_id ) . '">' . $post->post_title . '</a></h3>';
		$message .= wpautop( wptexturize( wp_kses_post( strip_shortcodes( $post->post_content ) ) ) );
		$message .= '<hr /><p>Posted by <a href="' . get_author_posts_url( $post->post_author ) . '">' . get_the_author_meta( 'display_name', $post->post_author ) . '</a>.</p>';
		$message .= '<p>View the post and comments at <a href="' . get_permalink( $post_id ) . '">' . get_permalink( $post_id ) . '</a>.</p>';
		$message .= '</body></html>';

		// Get the users who want emails
		$users = get_users( array( 'meta_key' => 'snpe_send' ) );

		$subject = apply_filters( 'snpe_subject', $subject, $post );
		$message = apply_filters( 'snpe_message', $message, $post );
		$users = apply_filters( 'snpe_users', $users, $post );

		if ( empty( $users ) ) {
			return;
		}

		$sent = $this->send_mail( $users, $subject, $message, $post );

		if ( $sent ) {
			update_post_meta( $post_id, 'snpe_sent', 'Y' );
		}
	}

	private function send_mail( $users, $subject, $message, $post ) {
		// BCC all users specified
		$headers = array();

		foreach ( (array) $users as $user ) {
			$headers[] = 'Bcc: ' . $user->user_email;
		}

		$headers[] = "Content-Type: text/html; charset=utf-8\r\n";
		$headers = apply_filters( 'snpe_headers', $headers, $post, $users );

		// Get the site domain and get rid of www.
		// Borrowed from wp-includes/pluggable.php
		$sitename = strtolower( $_SERVER['SERVER_NAME'] );
		if ( substr( $sitename, 0, 4 ) == 'www.' ) {
			$sitename = substr( $sitename, 4 );
		}

		$to = apply_filters( 'snpe_to_email', 'wordpress@' . $sitename, $post );

		return wp_mail( $to, $subject, $message, $headers );
	}

	/**
	 * Add a column to the Users admin table indicating subscription status
	 * @param array $columns    User table columns
	 *
	 * @return array
	 */
	public function add_snpe_user_column( $columns ) {
		$columns['snpe_send'] = 'Email New Posts?';
		return $columns;
	}

	/**
	 * Return a user-friendly string based on the value of the user meta field
	 * @param string $value Passed column value
	 * @param string    $column_name    Passed column name
	 * @param int   $user_id    User ID
	 *
	 * @return string
	 */
	public function show_snpe_user_column_content( $value, $column_name, $user_id ) {
		$snpe_send = get_user_meta( $user_id, 'snpe_send', true );
		if ( 'snpe_send' == $column_name ) {
			return ( true == $snpe_send ) ? 'Yes' : 'No';
		}
		return $value;
	}
}

$simple_new_post_emails = new Simple_New_Post_Emails();