/wp-content/plugins/wr-pagebuilder/core/utils/common.php

<?php
/**
 * WR PageBuilder Common functions
 *
 * Common functions (pure data, don't relate to IGPB shortcodes)
 *
 * @author         WooRockets Team <support@www.woorockets.com>
 * @package        IGPGBLDR
 * @version        $Id$
 */

class WR_Pb_Utils_Common {

	/**
	 * Delete meta keys
	 *
	 * @global type $wpdb
	 * @param type $keys
	 * @param type $post_id
	 * @return type
	 */
	static function delete_meta_key( $keys, $post_id = null ) {
		if ( empty ( $keys ) || ! count( $keys ) ) {
			return false;
		}
		global $wpdb;
		$extra = ! empty ( $post_id ) ? 'post_id = ' . esc_sql( $post_id ) . ' AND' : '';

		$sql = "DELETE FROM $wpdb->postmeta WHERE $extra meta_key IN (".implode(', ', array_fill(0, count($keys), '%s')).")";

		// Call $wpdb->prepare passing the values of the array as separate arguments
		$query = call_user_func_array(array($wpdb, 'prepare'), array_merge(array($sql), $keys));
		$wpdb->query( $query );

		// del all blog
		if( is_network_admin() ){
			// get list id blog all
			$list_prefix_musite = $wpdb->get_results(
				"SELECT blog_id FROM $wpdb->blogs",
				ARRAY_A
			);

			if($list_prefix_musite && count($list_prefix_musite) > 1){
				foreach ($list_prefix_musite as $key => $value) {
					if ($value['blog_id'] == 1) continue;

					$prefix = $wpdb->prefix.$value['blog_id'].'_';
					$sql = "DELETE FROM {$prefix}postmeta WHERE $extra meta_key IN (".implode(', ', array_fill(0, count($keys), '%s')).")";

					// Call $wpdb->prepare passing the values of the array as separate arguments
					$query = call_user_func_array(array($wpdb, 'prepare'), array_merge(array($sql), $keys));
					$wpdb->query( $query );
				}
			}
		}
	}

	/**
	 * Remove cache folder
	 *
	 * @return type
	 */
	static function remove_cache_folder() {
		$cache_dir = WP_CONTENT_DIR . '/uploads' . '/igcache/pagebuilder';
		WR_Pb_Utils_Common::recursive_delete( $cache_dir );

		// if directory still exits, false
		if ( is_dir( $dir ) ) {
			return false;
		}

		return true;
	}

	/**
	 * Remove directory
	 *
	 * @param type $dir
	 */
	static function recursive_delete( $dir ) {
		if ( is_dir( $dir ) ) {
			global $wp_filesystem;

			if ( ! function_exists( 'WP_Filesystem' ) ) {
				include_once ABSPATH . 'wp-admin/includes/file.php';
			}
			if ( ! $wp_filesystem ) {
				WP_Filesystem();
			}
			$deleted = $wp_filesystem->delete( $dir, true );

			return $deleted;
		}
	}

	/**
	 * Generate random string
	 *
	 * @param type $length
	 * @param type $is_lower_no_number
	 *
	 * @return string
	 */
	static function random_string( $length = 6, $is_lower_no_number = false ) {
		if ( ! $is_lower_no_number ) {
			$characters = '0123456789abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ';
		} else {
			$characters = 'abcdefghijklmnopqrstuvwxyz';
		}

		$randomString = '';
		for ( $i = 0; $i < $length; $i ++ ) {
			$randomString .= $characters[rand( 0, strlen( $characters ) - 1 )];
		}

		return $randomString;
	}

	/**
	 * remove ' and " from string
	 *
	 * @param type $str
	 *
	 * @return type
	 */
	static function remove_quotes( $str ) {
		$str    = stripslashes( $str );
		$result = preg_replace( "/[\'\"]+/", '', $str );

		return $result;
	}

	/**
	 * Slice to get nth-child first word
	 *
	 * @param type $content
	 */
	static function slice_content( $content ) {
		$content = urldecode( $content );
		$content = strip_tags( $content );
		$arr     = explode( ' ', $content );
		$arr     = array_slice( $arr, 0, 10 );

		return implode( ' ', $arr );
	}

	/**
	 * Trim content to : $limit_count $limit_type ( 5 words, 20 characters ... )
	 *
	 * @param type $content
	 * @param type $limit_count
	 * @param type $limit_type
	 */
	static function trim_content( $content, $limit_count, $limit_type ) {
		if ( empty( $limit_count ) ) {
			return $content;
		}
		$content = trim( $content );
		$content = strip_tags( $content );
		if ( $limit_type == 'words' ) {
			$content = implode( ' ', array_slice( explode( ' ', $content ), 0, intval( $limit_count ) ) );
		} else {
			if ( $limit_type == 'characters' ) {
				$content = substr( $content, 0, intval( $limit_count ) );
			}
		}

		return balanceTags( $content );
	}

	/**
	 * Generate random lorem ipsum text
	 *
	 * @param type $word_count
	 *
	 * @return type
	 */
	static function lorem_text( $word_count = 50, $lorem_start = false ) {
		$words  = array( 'lorem', 'ipsum', 'dolor', 'sit', 'amet', 'consectetur', 'adipiscing', 'elit', 'curabitur', 'vel', 'hendrerit', 'libero', 'eleifend', 'blandit', 'nunc', 'ornare', 'odio', 'ut', 'orci', 'gravida', 'imperdiet', 'nullam', 'purus', 'lacinia', 'a', 'pretium', 'quis', 'congue', 'praesent', 'sagittis', 'laoreet', 'auctor', 'mauris', 'non', 'velit', 'eros', 'dictum', 'proin', 'accumsan', 'sapien', 'nec', 'massa', 'volutpat', 'venenatis', 'sed', 'eu', 'molestie', 'lacus', 'quisque', 'porttitor', 'ligula', 'dui', 'mollis', 'tempus', 'at', 'magna', 'vestibulum', 'turpis', 'ac', 'diam', 'tincidunt', 'id', 'condimentum', 'enim', 'sodales', 'in', 'hac', 'habitasse', 'platea', 'dictumst', 'aenean', 'neque', 'fusce', 'augue', 'leo', 'eget', 'semper', 'mattis', 'tortor', 'scelerisque', 'nulla', 'interdum', 'tellus', 'malesuada', 'rhoncus', 'porta', 'sem', 'aliquet', 'et', 'nam', 'suspendisse', 'potenti', 'vivamus', 'luctus', 'fringilla', 'erat', 'donec', 'justo', 'vehicula', 'ultricies', 'varius', 'ante', 'primis', 'faucibus', 'ultrices', 'posuere', 'cubilia', 'curae', 'etiam', 'cursus', 'aliquam', 'quam', 'dapibus', 'nisl', 'feugiat', 'egestas', 'class', 'aptent', 'taciti', 'sociosqu', 'ad', 'litora', 'torquent', 'per', 'conubia', 'nostra', 'inceptos', 'himenaeos', 'phasellus', 'nibh', 'pulvinar', 'vitae', 'urna', 'iaculis', 'lobortis', 'nisi', 'viverra', 'arcu', 'morbi', 'pellentesque', 'metus', 'commodo', 'ut', 'facilisis', 'felis', 'tristique', 'ullamcorper', 'placerat', 'aenean', 'convallis', 'sollicitudin', 'integer', 'rutrum', 'duis', 'est', 'etiam', 'bibendum', 'donec', 'pharetra', 'vulputate', 'maecenas', 'mi', 'fermentum', 'consequat', 'suscipit', 'aliquam', 'habitant', 'senectus', 'netus', 'fames', 'quisque', 'euismod', 'curabitur', 'lectus', 'elementum', 'tempor', 'risus', 'cras', );
		$result = array();
		if ( $lorem_start ) {
			$result[]    = 'lorem';
			$word_count -= 1;
		}
		for ( $i = 0; $i < $word_count; $i ++ ) {
			$random_index = rand( 0, $word_count );
			$result[]     = $words[$random_index];
		}

		return implode( ' ', $result );
	}
}