Tag: Webmastering

Mobile vs. Desktop CSS switch for Web app with Server Side rendering

When modern web application is built using Server Side Rendering (SSR) or Static Site Generator (SSG) technology it is hard to decide which version, Mobile or Desktop, should be served.

If you are not planning to have separate domains or subdomains for mobile-first and desktop-first versions of your Web App, here is a useful trick:

  // In main App or Layout component add following:

  const isMobile = useMediaQuery({ maxWidth: 767 }); // From any library

  useEffect(() => {
    if (isMobile) {
      document.body.classList.remove('onDesktop');
      document.body.classList.add('onMobile');
    } else {
      document.body.classList.remove('onMobile');
      document.body.classList.add('onDesktop');
    }
  }, [isMobile]);

This is sample for React library, but can be easily implemented for any other frontend framework.

The idea is simple: to have .onMobile or .onDesktop CSS class modifier for the <body> tag

In that case mobile specific styles are .onMobile .abc {...} and desktop CSS is .onDesktop .abc {...}

Happy hacking 🙂

List of Categories and List of Tags for WordPress website

There is no standard way to list non-empty categories or output the list of all tags in WordPress.

Here are code of two useful “shortcodes”:

/**
 * Generates list of categories. Set $atts('counts' => true) to show number of items in every category 
 */
function html_list_categories( $atts ) { 
	$terms = get_terms( 'category', array('hide_empty' => true) );
	if ( !$terms ) return '';

	if ( isset($atts['counts']) ) $showCounts = $atts['counts']; else $showCounts = false;

	$li_items = '';
	foreach( $terms as $t ) {
		$li_items .= "\t" . '<li class="cat-item"><a href="' . get_term_link($t) . '"'; 		  
			if ( $t->description != '') $li_items .= ' title="' . $t->description  . '"'; // add title if description is set		  
		$li_items .= '>'. $t->name . "</a>";
			if ( $showCounts ) $li_items .= " (" . $t->count . ")</li>"; // add count if required
		$li_items .= "\n";
	};

	return "\n<ul class=\"cat-list\">\r\n{$li_items}</ul>\n";
};
add_shortcode( 'list_categories', 'html_list_categories' ); 

/**
 * Generates list of tags. Set $atts('counts' => true) to show number of items for every tag
 */
function html_list_tags( $atts ) { 
	$terms = get_terms( 'post_tag', array('hide_empty' => false) );
	if ( !$terms ) return '';
  
	if ( isset($atts['counts']) ) $showCounts = $atts['counts']; else $showCounts = false;

	$li_items = '';
	foreach($terms as $t) {
		$li_items .= "\t" . '<li class="tag-item"><a href="' . get_term_link($t) . '"'; 		  
			if ( $t->description != '') $li_items .= ' title="' . $t->description  . '"'; // add title if description is set		  
		$li_items .= '>'. $t->name . "</a>";
			if ( $showCounts ) $li_items .= " (" . $t->count . ")</li>"; // add count if required
		$li_items .= "\n";
	};
	
	return "\n<ul class=\"tag-list\">\n{$li_items}</ul>\n";
}
add_shortcode( 'list_tags', 'html_list_tags' );

You can add this code directly into your WordPress theme (function.php or header.php file). But we strongly advice to use one of “code plugins”: Code Snippets, PHP Snippets, etc.

To output Category or Tag lists use “shortcode” in your post or page:

[list_categories]

[list_tags counts="true"]

You can style lists in your own way using CSS classes:

.cat-list {
...
}
.cat-item {
...
}
.tag-list {
...
}
.tag-item {
...
}

Adding Categories and Tags into WordPress Pages

Wordpress CMS is a very popular one, but some features and settings are strange.

The most common question people creating content for websites based on this CMS ask is the following:

Why WordPress Posts have Category and Tag settings but WordPress Pages have neither Categories nor Tags?

Here is a quick fix: 

// Allow Categories and Tags in GUI of Page Editor 
function add_taxonomies_to_pages() {
	register_taxonomy_for_object_type('category', 'page');
	register_taxonomy_for_object_type('post_tag', 'page');
}
add_action('init', 'add_taxonomies_to_pages');

// Add Pages into Categories and Tags Archives 
function category_and_tag_archives($query) {
	// If you have custom post types add them into this array
	$my_post_array = array('post', 'page'); 

	if ($query->get('category_name') || $query->get('cat'))
		$query->set('post_type', $my_post_array);

	if ($query->get('tag'))
		$query->set('post_type', $my_post_array);
}
if (!is_admin()) {
	add_action('pre_get_posts', 'category_and_tag_archives');
}

You can add this code directly into your WordPress theme (function.php or header.php file).

But a safer way is to use one of plugins allowing to execute PHP code (Code Snippets, PHP Snippets, and so on). In this case WordPress Pages will still have Categories and Tags even if somebody changes (or updates) the theme of your site 🙂

Backup of Firewall settings is Important

If you use a web server (no matter with Linux, Unix or Windows) you should keep it safe. The firewall is the first place where you need to setup the system security.

It is necessary to restrict access to the server by specific protocols and ports. More precisely, on the server firewalls you need to close all ports and open only the most necessary ones 🙂

Linux kernel firewall works with iptables space. You can manually make entries in the iptables configs (different files in /etc/ or /etc/sysconfig/ depending on the Linux version). If you use some visual management panel (Webmin, WHM, CPanel, Plesk, etc.) tuning the Linux firewall become a pleasure.

But independently of managing methods, do not forget to make a regular copies of the firewall settings! Accidental clicking of some button in control panel can suspend all the rules and make your server vulnerable. Deleting or modification of the configuration file by some hacking scripts can do the same.

In general, for servers on the Linux system, the regular backup of the iptables config files is a must do task for webmaster. Backups for security settings are usually scheduled on Unix and Windows servers too.

Backup firewall settings regularly and keep your web-servers secure!