Solutions for frequent WordPress problems

functions.php

<?php


/*
 * Solutions for frequent wordpress problems
 */


// remove the emoji code
function disable_wp_emojicons() {
  // all actions related to emojis
  remove_action( 'admin_print_styles', 'print_emoji_styles' );
  remove_action( 'wp_head', 'print_emoji_detection_script', 7 );
  remove_action( 'admin_print_scripts', 'print_emoji_detection_script' );
  remove_action( 'wp_print_styles', 'print_emoji_styles' );
  remove_filter( 'wp_mail', 'wp_staticize_emoji_for_email' );
  remove_filter( 'the_content_feed', 'wp_staticize_emoji' );
  remove_filter( 'comment_text_rss', 'wp_staticize_emoji' );
  // filter to remove TinyMCE emojis
  add_filter( 'tiny_mce_plugins', 'disable_emojicons_tinymce' );
}
add_action( 'init', 'disable_wp_emojicons' );

// remove the <link rel='https://api.w.org/' href='http://mydomain.com/wp-json/' /> in the header
remove_action('wp_head', 'rest_output_link_wp_head', 10);
// remove_action('wp_head', 'wp_oembed_add_discovery_links', 10);

// remove the wp-embed.min.js in the footer
function disable_embeds_init() {
    // Remove the REST API endpoint.
    remove_action('rest_api_init', 'wp_oembed_register_route');
    // Turn off oEmbed auto discovery.
    // Don't filter oEmbed results.
    remove_filter('oembed_dataparse', 'wp_filter_oembed_result', 10);
    // Remove oEmbed discovery links.
    remove_action('wp_head', 'wp_oembed_add_discovery_links');
    // Remove oEmbed-specific JavaScript from the front-end and back-end.
    remove_action('wp_head', 'wp_oembed_add_host_js');
}
add_action('init', 'disable_embeds_init', 9999);

// disable REST API
add_filter('rest_enabled', '_return_false');
add_filter('rest_jsonp_enabled', '_return_false');

//nuke the stupid admin bar on the frontend
function off_admin_bar(){return false;}
add_filter('show_admin_bar','off_admin_bar');


//prevent wp-pagenavi to inject the CSS
add_action('wp_print_styles', 'my_deregister_styles', 100);
function my_deregister_styles() {
    wp_deregister_style('wp-pagenavi');
}


//prevent akismet from injecting a javascript on EVERY page
add_action('wp_print_scripts', 'my_deregister_scripts', 100);
function my_deregister_scripts() {
	wp_deregister_script('akismet-form');
	if (is_page('submit') || is_page('screenshot-upload')) {
		wp_register_script( 'akismet-form', '/akismet-form.js');
        //wp_enqueue_script( 'my-akismet-script', '/akismet-form.js', array('jquery','akismet-form'));
	}
}


/*
this is not working and I do not know why...

	//change the post title for a single post
	function overwrite_post_title($title, $sep) {
		global $post;
	
		//if ( is_single($post->ID) && !is_attachment() )
			$title = "Title here";

		return $title;
	}
	add_filter( 'wp_title', 'overwrite_post_title', 10, 2);
*/


//allow filtering for empty content in post queue
add_filter('wp_sucks_hard','filter_empty_content');
function content_empty_filter_where($where = ''){
	$where .= "AND post_status = 'pending'
		   AND post_type = 'post'
		   AND trim(coalesce(post_content, '')) <>''";
}
function filter_empty_content()
{
	add_filter('posts_where', 'content_empty_filter_where');
	$wp_query = new WP_Query(
		array(
			'post_status' => "pending",
			'post_type' => 'post',
			'posts_per_page' => 10,
			'paged' => intval($qv),
		)
	);
	remove_filter('posts_where', 'content_empty_filter_where');
	return $wp_query;
}


//extract street view camera information from URL
function get_camera_angle($url, $embed = false){

	//camera defaults
	$camera = array(
			1 => '12',
			2 => '221.3',
			3 => '',
			4 => '0',
			5 => '5.0',
			);
	//$camera[1]: hemisphere: map arrangement, 11=upper half Street View and lower half map, 12=mostly Street View with corner map
	//$camera[2]: heading
	//$camera[3]: empty
	//$camera[4]: zoom
	//$camera[5]: pitch

	if(!$url) return $camera;

	//camera
	$camera = array();
	$found = preg_match('~&cbp=(-?\d*),(-?\d+\.?\d*),(-?\d*\.?\d*),(-?\d+),(-?\d+\.?\d*)~', $url, $camera);

	if($found)
	{
		//validation
		//for($i = 1; $i < 5; $i++)
		//$camera[$i] = floatval($camera[$i]);

		//zoom zero looks ugly!
		if($camera[4]=='0') $camera[4] = 1;
		$camera[4] = floatval($camera[4]) * 1.8;

		//hemisphere check
		//if($camera[1] == '13')

		//reverse camera tilt for embed
		//if($embed && $camera[1] < 0)
		//	$camera[5] = -1 * $camera[5];

	}
	else
	{
		//try to get the camera info from the new link format

		$matches = array();

		/*
			https://www.google.com/maps/@6.253567,-75.570244,3a,
			41.8y,309.35h,88.27t
			/data=!3m4!1e1!3m2!1sRgEjExgvRm63dsi2JvzD2g!2e0
		*/

		if( preg_match('~,(\-?\d+\.?\d*)y,(\-?\d+\.?\d*)h,(\-?\d+\.?\d*)t~', $url, $matches) )
		{

			$camera[2] = $matches[2];

			//zoom control
			if(intval($matches[1]) > 20)
				$camera[4] = 1;
			else
				$camera[4] = 3;

			$camera[5] = round(90 - $matches[3], 2);

		}

	}

	return $camera;

} //get_camera_angle


//extract coordinates from a street view url
function get_coords($url){

	$matches = array();

	//***CASE 1: (Street View)
	//http://maps.google.com/?ie=UTF8&ll=42.353242,-99.284355&spn=0,73.300781&t=h&z=4&layer=c&cbll=39.353842,-100.189355&panoid=l4MtZ86H1-nVKJbrATrONw&cbp=12,342.31,,0,5
	$found = preg_match("~&cbll=(\-?\d+\.?\d*),(\-?\d+\.?\d*)~si", $_POST['submission']['url'], $matches);

	if($found)
	{
		//echo "CASE 1: StreetView";

		return array(
			array(1 => $matches[1], 2 => $matches[2]),
			'classic'
		);

	}
	else
	{

		//NEW STREET VIEW LINK FORMAT!
		//https://www.google.com/maps/@30.604732,-5.684273,3a,15y,177.38h,81.82t/data=!3m4!1e1!3m2!1sgs2wASH69rQWaQ8EsYonUA!2e0!6m1!1e1
		$found = preg_match("~@(\-?\d+\.?\d*),(\-?\d+\.?\d*)~si", $_POST['submission']['url'], $matches);

		if($found)
		{

			return array(
				array(1 => $matches[1], 2 => $matches[2]),
				'new'
			);

		}
		else
		{

			//***CASE 2:
			//21?51'23.46"S,  44? 1'44.80"W
			//or
			//41?12'27.84"N, 16?18'40.15"E

			$found = preg_match("~(\d+\s*\D+\d*\s*\'?\s*\d*\s*\.?\s*\d*\s*\"?\s*[N|S])\s*,\s*(\d+\s*\D+\s*\d*\s*\'?\s*\d*\s*\.?\s*\d*\s*\"?\s*[E|W])~i", $_POST['submission']['url'], $matches);

			// (\d+)\D+(\d+)\D+(\d+)\.(\d+)\W(\w+)\W+(\d+)\D+(\d+)\D+(\d+)\.(\d+)\W(\w)

			if($found)
			{
				//echo "CASE 2: 20?52'23.46\"S, 40? 2'44.80\"W<br />";

				//get the coords to filter out the crap
				for($i = 1; $i<=2; $i++)
				{
					//reset
					$temp = array();

					$found = preg_match("~(\d+)\s*\D+\s*(\d*)\s*\'?\s*(\d*)\s*\.?\s*(\d*)\s*\"?\s*([N|S|W|E])~iU", $matches[$i], $temp);

					$matches[$i] = number_format( $temp[1]+ //degrees
							+($temp[2]/60)+//min
							(($temp[3]+($temp[4]/100))/3600) //sec
							, 5); //five decimals

					if($temp[5]=='S' || $temp[5]=='W')
						$matches[$i] = $matches[$i] * (-1);
				}

				return array(
					array(1 => $matches[1], 2 => $matches[2]),
					'degree'
				);

			}
			else
			{
				//***CASE 3: (Google Maps)
				//http://maps.google.com/?ie=UTF8&ll=30.0225,-92.627068&spn=42.445866,73.300781&t=h&z=17
				//okay

				$found = preg_match("~&ll=(\-?\d+\.?\d*),(\-?\d+\.?\d*)~si", $_POST['submission']['url'], $matches);

				if($found) //found streetview coordinates
				{
					//echo "CASE 3: Google Maps";

					return array(
						array(1 => $matches[1], 2 => $matches[2]),
						'map'
					);

				}
				else
				{

					//***CASE 4:
					//-11.123 , -12.1234
					$found = preg_match("~^(\-?\d+\.?\d*)\s*,\s*(\-?\d+\.?\d*)$~si", $_POST['submission']['url'], $matches);

					if($found)
					{
						//echo "CASE 4: -11.123 , -12.1234";

						return array(
							array(1 => $matches[1], 2 => $matches[2]),
							'decimal'
						);

					}
				}
			}
		}
	}
}


//enable viewing of pending posts for guests
function guest_enable_hidden_single_post($query){

	//if (is_user_logged_in()) return;

	//user is not logged

	// ($query->is_single() || $query->is_category() ) &&
	if ( $query->is_main_query() )
	{
	    //allowed post statuses for guest
	    $query->set('post_status', array('publish','pending'));
	}

}
function guest_reload_hidden_single_post($posts){

    global $wp_query, $wpdb;

    //if (is_user_logged_in()) return $posts;

    //user is not logged

	// && ($wp_query->is_single() || $wp_query->is_category() )
	if ( !$wp_query->post_count && $wp_query->is_main_query() )
	{
	    $posts = $wpdb->get_results($wp_query->request);
	}

    return $posts;
}
//allow guests to view single posts even if they have not post_status="publish"
add_filter('pre_get_posts','guest_enable_hidden_single_post');
//reload hidden posts
add_filter('the_posts','guest_reload_hidden_single_post');


//allow uploads of additional photos for each post
//create a custom post type
add_action( 'init', 'create_photo_type' );
function create_photo_type() {
	register_post_type( 'photo_upload',
		array(
			'labels' => array(
				'name' => __( 'Photos' ),
				'singular_name' => __( 'Photo' ),
				'edit_item' => __( 'Edit Photos' ),
			),
			'public' => true,
			'publicly_queryable' => false,
			'exclude_from_search' => true,
			'has_archive' => true,
			'capability_type' => 'post',
			'show_ui' => false,
			'show_in_nav_menus' => false,
			'hierarchical' => false,
			'supports' => array( 'comments' ),
			'rewrite' => array('slug' => 'photos')
		)
	);
}


/*
//add links to admin bar
function add_sumtips_admin_bar_link() {
	global $wp_admin_bar;
	if ( !is_super_admin() || !is_admin_bar_showing() )
		return;
	$wp_admin_bar->add_menu( array(
	'id' => 'sumtips_link',
	'title' => __( 'Submit'),
	'href' => __('http://domain.com/submit/'),
	) );
}
add_action('admin_bar_menu', 'add_sumtips_admin_bar_link', 99);
*/


//a simple link that allows to delete a post from the frontend
function wp_delete_post_link($link = 'delete', $before = '', $after = '')
{
	global $post;
//	if ( $post->post_type == 'page' ) {
//		if ( !current_user_can( 'edit_page', $post->ID ) )
//			return;
//	} else {
		if ( !current_user_can( 'edit_post', $post->ID ) )
			return;
//	}
	$link = "<a href='" . wp_nonce_url( get_bloginfo('url') . "/blog/wp-admin/post.php?action=delete&amp;post=" . $post->ID, 'delete-post_' . $post->ID) . "'>".$link."</a>";
	echo $before . $link . $after;
}


//is_admin variable
$is_admin = false;
if(function_exists('is_admin') && is_admin()) $is_admin = true;


//remove shortlink meta crap
remove_action( 'wp_head', 'wp_shortlink_wp_head', 10, 0 );


//don't add stupid <p> tags to content
//remove_filter ('the_content',  'wpautop');


//don't add stupid <p> tags to comments
remove_filter ('comment_text', 'wpautop');


//enable thumbnails in theme
if (function_exists('add_theme_support')) {
    add_theme_support('post-thumbnails');
}


//calculate the distance between two coordinates
function distance_calc($lat1, $lng1, $lat2, $lng2)
{
	$pi80 = M_PI / 180;
	$lat1 *= $pi80;
	$lng1 *= $pi80;
	$lat2 *= $pi80;
	$lng2 *= $pi80;

	$r = 6372.797; // mean radius of Earth in km
	$dlat = $lat2 - $lat1;
	$dlng = $lng2 - $lng1;
	$a = sin($dlat / 2) * sin($dlat / 2) + cos($lat1) * cos($lat2) * sin($dlng / 2) * sin($dlng / 2);
	$c = 2 * atan2(sqrt($a), sqrt(1 - $a));
	$km = $r * $c;

	return $km;
}


//wp-post-ratings / supercache fix
function get_rating_ajax($id) {
	if(function_exists('the_ratings')) //plugin enabled
	{
		$nonce = wp_create_nonce('my_rating');
		echo '<div id="ratings-wrap-'.$id.'"><img src="/img/loading-ratings.gif" alt="" /></div><script type="text/javascript"><!--';
		echo 'jQuery(document).ready(function($){$.ajax({type : "GET",';
		echo 'url : "'.get_option('home').'/wp-content/plugins/wp-postratings/wp-postratings.php",';
		echo 'data : { wp_ajaxaction : "jquery", post_id : '.$id.', _ajax_check : "'.$nonce.'"},';
		echo 'success : function(response){$("#ratings-wrap-'.$id.'").html(response);}';
		echo '});});//-->';
		echo '</script>';
	}
}


//remove pingback header
function remove_x_pingback($headers) {
    unset($headers['X-Pingback']);
    return $headers;
}
add_filter('wp_headers', 'remove_x_pingback');


// @param string $str The text string to split
// @param integer $words The number of words to extract. Defaults to 15
function word_split($str,$words=20) {
	$arr = preg_split("/[\s]+/", $str,$words+1);
	$arr = array_slice($arr,0,$words);
	return join(' ',$arr);
}


function compare_dates($date1, $date2='') {

    if(empty($date2)) $date2 = time();

    $blocks = array(
        array('name'=>'year','amount'    =>    60*60*24*365    ),
        array('name'=>'month','amount'    =>    60*60*24*31    ),
        array('name'=>'week','amount'    =>    60*60*24*7    ),
        array('name'=>'day','amount'    =>    60*60*24    ),
        array('name'=>'hour','amount'    =>    60*60        ),
        array('name'=>'minute','amount'    =>    60        ),
        array('name'=>'second','amount'    =>    1        )
        );

    $diff = abs($date1-$date2);

    $levels = 2;
    $current_level = 1;
    $result = array();
    foreach($blocks as $block)
        {
        if ($current_level > $levels) {break;}
        if ($diff/$block['amount'] >= 1)
            {
            $amount = floor($diff/$block['amount']);
            if ($amount>1) {$plural='s';} else {$plural='';}
            $result[] = $amount.' '.$block['name'].$plural;
            $diff -= $amount*$block['amount'];
            $current_level++;
            }
        }
    return implode(' ',$result).' ago';
}


/*
//change src of attachment images!
//function chg_image_tag($html, $id , $alt, $title){
//
//	$post_url = "XXX";
//
//	$html = preg_replace("~\"[\w\./]*\"~", $post_url, $html);
//
//	return $html;
//}
//add_filter('get_image_tag','chg_image_tag',10,2);
*/


//remove traces of the site being wordpress by exchanging javascript files
add_action('init', 'remheadlink');
function remheadlink() {
	remove_action('wp_head', 'rsd_link');
	remove_action('wp_head', 'wlwmanifest_link');
	remove_action('wp_head', 'wp_generator');

	//use newest jquery
	if(!is_admin()){
	   wp_deregister_script('jquery');
	   wp_register_script('jquery', "http://ajax.googleapis.com/ajax/libs/jquery/1.11.0/jquery.min.js", false, '');
	   wp_enqueue_script('jquery');
	}
	//exchange the postratings.js without editing the plugin
	if(function_exists('the_ratings') && !is_admin()){
	   wp_deregister_script('wp-postratings');
	   wp_register_script('wp-postratings', "/postratings-js.js", false, '1.50');
	   wp_enqueue_script('wp-postratings');

	   wp_deregister_style('wp-postratings');
	   wp_register_style('wp-postratings', "/postratings-css.css", false, '1.50');
	   wp_enqueue_style('wp-postratings');
	}
}


//filter posts being tagged with a single tag
add_action('get_header', 'block_singletag');
	function singletag_wordpress_groupby($groupby)
	{
		if(empty($groupby)) $groupby = "wp_posts.ID";
		return $groupby . "
					HAVING COUNT( tag_terms.term_id ) <> 1
					OR MAX( tag_terms.term_id ) <> 1122 ";
	}
	function singletag_wordpress_join($join)
	{
		return $join . " INNER JOIN wp_term_relationships AS tag_term_relationships ON (wp_posts.ID = tag_term_relationships.object_id)
			INNER JOIN wp_term_taxonomy AS tag_term_taxonomy ON (tag_term_relationships.term_taxonomy_id = tag_term_taxonomy.term_taxonomy_id AND tag_term_taxonomy.taxonomy = 'post_tag')
			INNER JOIN wp_terms AS tag_terms ON (tag_term_taxonomy.term_id = tag_terms.term_id) ";
	}

function block_singletag()
{
	if(is_home() || is_tag() || (is_single() && !is_page(22552)) || (!is_page(22552) && !has_tag(array('articles','videos')))) //not submission queue or article
	{
		//exclude the single tag from showing up
		//$includetags = array(107,1127,1140,1141,932,3,1151,1143,1139,1142,1316,1138,950);
		$excludetags = array(599,1122);

		//posts_groupby hook to remove single tag posts
		//full query:
		//SELECT SQL_CALC_FOUND_ROWS wp_posts.* FROM wp_posts
		//		INNER JOIN wp_term_relationships AS tag_term_relationships ON (wp_posts.ID = tag_term_relationships.object_id)
		//		INNER JOIN wp_term_taxonomy AS tag_term_taxonomy ON (tag_term_relationships.term_taxonomy_id = tag_term_taxonomy.term_taxonomy_id AND tag_term_taxonomy.taxonomy = 'post_tag')
		//		INNER JOIN wp_terms AS tag_terms ON (tag_term_taxonomy.term_id = tag_terms.term_id)
		//WHERE 1=1 AND wp_posts.post_type = 'post' AND (wp_posts.post_status = 'publish') GROUP BY wp_posts.ID HAVING COUNT( tag_terms.term_id ) <> 1 OR MAX( tag_terms.term_id ) <> 1122 ORDER BY wp_posts.post_date DESC LIMIT 0, 10

		//1: add join tags into query (to receive the above query)
		add_filter('posts_join', 'singletag_wordpress_join', 10);

		//2: exclusion of single tag
		add_filter('posts_groupby', 'singletag_wordpress_groupby', 10);
	}
}


//kill the wordpress database connection page is done loading!
add_action('shutdown','close_up_shop');
function close_up_shop() {
	@mysql_close();
}