Carey Dayrit

Caching 404 pages in WordPress

This is to stop WordPress in handling 404, using headers to manage cache expiry. This code should be added to the theme’s functions.php file.

function template_slug_404_cache() {
	if( is_404() ){
		header( 'Cache-Control: max-age=30000, must-revalidate' );
		header( 'Expires: ' . date( 'D, d M Y H:i:s', strtotime( '+5000 minutes' ) ) . 'UTC' );
		header( 'Last-Modified: ' . date( 'D, d M Y H:i:s', strtotime( '-5000 minutes' ) ) . 'UTC' );        
	}
}

/**
 * Redirect a 404 to a cache page
 *
 * @return void
 */
function template_slug_404_redirect() {
	if ( is_404() ) {
		header( 'Location:' . site_url( '/404' ) );
		exit();
	}
}
add_action( 'template_redirect', 'template_slug_404_cache' );

Be sure that there is a 404.php file on the template directory.

November 30, 2022 by Carey Pantheon PHP Wordpress 0

Add a help tab to a WordPress Plugin

This is a help tab that can be found on the WordPress admin dashboard, a custom plugin can have also contextual help that can be found on the rightmost part of the admin screen.

Ever since WordPress Version 3.0, every built-in Administration Panel has contained a contextual help section providing additional information to the user on how to navigate the various settings displayed in that admin panel. This helps WordPress keep the main part of the admin panel clear and concise by eliminating unnecessary text that regular users don’t need to see on a regular basis.
https://codex.wordpress.org/Adding_Contextual_Help_to_Administration_Menus

We should use the Screen class to achieve adding the help tab.

This is a concrete class that is instantiated in the WordPress $screen global. It is primarily used to create and customize WordPress admin screens (as of WordPress 3.3).
https://developer.wordpress.org/reference/classes/wp_screen/

An example function to add a help tab using the WP_Screen class.

function my_add_help_tab() {
	$screen = get_current_screen();
	$screen->add_help_tab(
		array(
			'id' => 'hello_dolly',
			'title' => __( 'Hello Dolly' ),
			'content' => '<p>' . Well, hello, Dolly
It's so nice to have you back where you belong
You're lookin' swell, Dolly . '</p>',
		)
	);
	$screen->set_help_sidebar( __( 'Hello Dolly' ) );
}

There are two methods that are used add_help_tab and the set_help_sidebar. The add_help_tab would add the tab button on the screen and also the left-side title and the content.

The set_help_side_bar would add an additional third column.

Upon activation of an Options page or Menu page, use an action hook and use the callback function.

function my_options_page() {
	$my_menu_page = add_menu_page(
		'Hello_Dolly',
		'Hello Dolly',
		'manage_options',
		'wpl',
		'wpl_options_page_html'  // callback function to display the page
	);
	// Add help bar.
	add_action( 'load-' . $my_menu_page, 'my_add_help_tab' );
}

add_action( 'admin_menu', 'my_options_page' );

That’s all to it.

October 22, 2022 by Carey PHP Wordpress 0

WordPress 6.0.3

WordPress.org has a new security update. This is a very important release because it fixes most of the XSS (Cross Site Scripting) vulnerabilities.

Widget block
Feature Image block
RSS Block
Search Block
Stored XSS via wp-mail.php
customizer

Another is the sanitation of the class WP_Date_Query. Be sure to update to the latest release. Download the latest version or update via WordPress dashboard.

October 18, 2022 by Carey Wordpress 0

Add a Section on WordPress Settings Page

The primary location to set up settings for various WordPress website parts is the Settings tab in the WordPress Admin sidebar.

Listed is the sub-menu for Settings Tab, these are:

General
Writing
Reading
Discussion
Media
Permalinks
Privacy

Fields can be added to these pages by creating a simple plugin.

The WordPress functions which would be used are:

register_setting() – this would register our additional options.

add_settings_section() – this would be the section belonging to our custom settings field

add_settings_field() – this would be the custom field

First, we need to use a function that would initialize our plugin.

function wpl_settings_init() {
	// register a new setting for "reading" page.
	register_setting(
		'reading',              // $option_group
		'wpl_setting_example',  // $option_name
		array(
			'array',
			/** 'callback',         // $sanitize_callback. */
		),
	);

	// register a new section in the "reading" page.
	add_settings_section(
		'wpl_settings_section',           // $id
		'WPL Settings Section',           // $title
		'wpl_settings_section_callback',  // $callback
		'reading'                         // $page
	);

	// register a new field in the "wpl_settings_section" section, ins.
	add_settings_field(
		'wpl_settings_option1',           // $id
		'Option 1',                      // $title
		'wpl_settings_option1_callback',  // $callback
		'reading',                       // $page
		'wpl_settings_section',          // $section
	);

	// register a new field in the "wpl_settings_section" section, ins.
	add_settings_field(
		'wpl_settings_option2',           // $id
		'Option 2',                     // $title
		'wpl_settings_option2_callback',  // $callback
		'reading',                      // $page
		'wpl_settings_section',         // $section
	);

}
add_action( 'admin_init', 'wpl_settings_init' );

In my example code, I have added two fields, and here are the callbacks.

function wpl_settings_section_callback() {
	echo '<p>WPL Section Introduction</p>';
}

function wpl_settings_option1_callback() {
	$setting = get_option( 'wpl_setting_example' );
	?>
	<input type="text" name="wpl_setting_example[option1]" value="<?php echo isset( $setting['option1'] ) ? esc_attr( $setting['option1'] ) : ''; ?>">	
	<?php
}

function wpl_settings_option2_callback() {
	$setting = get_option( 'wpl_setting_example' );
	?>
	<input type="text" name="wpl_setting_example[option2]" value="<?php echo isset( $setting['option2'] ) ? esc_attr( $setting['option2'] ) : ''; ?>">	
	<?php
}

Here’s the visual output.

That’s all to it. Happy coding.

October 9, 2022 by Carey Wordpress 0

Block IPs in WordPress on Pantheon

This article is about blocking IPs in Pantheon for sites using the WordPress CMS. Prevent unwanted traffic incidents that might result in site outages and billing overages.

Review the nginx-access.log.

Download the nginx-access.log on the LIVE environment. The logs can be accessed using SFTP or by using the provided script from Pantheon’s documentation. Be sure to combine all the logs for a day if the site plan has multiple application containers. Identify the IP that has the highest number of visits and verify it with https://www.abuseipdb.com/

$ cat ~/site-logs/nginx-access.log | awk -F\" '{print $8}' | awk '{print $1}' | sort -n | uniq -c | sort -nr | head -20

Use a WordPress Plugin to Block IPs

Be sure to install the plugin WP Traffic Jammer that can be downloaded at WordPress.org https://wordpress.org/plugins/traffic-jammer. The plugin has a wp-cli command that can be used on a remote wp-cli call using Terminus. It also has a settings page to add a single IP or an IP range.

Block the IP using Terminus.

Use remote wp-cli via terminus to block the IP.

$ terminus wp <sitename>.<env> -- jam block <ip>

To unblock the IP.

$ terminus wp <sitename>.<env> -- jam unblock <ip>

Block the IP on the WordPress Admin Dashboard.

On the Admin Dashboard, you would see the left side menu, click “Traffic Jammer” and add a single IP or IPs, CIDR format can be also used for IP ranges.

Block the IP using a PHP Snippet

Use a PHP snippet that can be added to wp-config.php file. This offers an advantage since it would be triggered before loading all the plugins and themes.

if ( $_SERVER['REMOTE_ADDR'] == '154.84.133.8' ) {
  header( 'HTTP/1.0 403 Forbidden' );
  exit;
}

September 19, 2022 by Carey Pantheon Wordpress 0