jetpack / modules / theme-tools / random-redirect.php

random-redirect.php in Jetpack – WP Security, Backup, Speed, & Growth 16.2, at modules/theme-tools/random-redirect.php

139 lines 5.2 KB

Raw Download Zip

1	<?php
2	/**
3	* Plugin Name: Random Redirect
4	* Plugin URI: https://wordpress.org/extend/plugins/random-redirect/
5	* Description: Allows you to create a link to yourblog.example.com/?random which will redirect someone to a random post on your blog, in a StumbleUpon-like fashion.
6	* Version: 1.2-wpcom
7	* Author: Matt Mullenweg
8	* Author URI: https://ma.tt/
9	* Text Domain: jetpack
10	*
11	* @package automattic/jetpack
12	*/
13
14	// phpcs:disable WordPress.Security.NonceVerification -- No changes to the site here, it just redirects.
15
16	/*
17	* This module was removed from the plugin in 13.6 and restored in 16.1. In the meantime some themes
18	* and plugins started shipping their own copy of the function below, so only declare it when nothing
19	* else has, to avoid a fatal error. The declaration must stay inside this conditional: PHP binds
20	* unconditional top-level function declarations when the file is compiled, before any check could run.
21	*/
22	if ( ! function_exists( 'jetpack_matt_random_redirect' ) ) {
23	/**
24	* Redirects to a random post on the site.
25	*/
26	function jetpack_matt_random_redirect() {
27	/**
28	* Allows disabling the random redirect feature.
29	*
30	* @since 16.1
31	*
32	* @param bool $enabled Whether the random redirect feature is enabled. Default true.
33	*/
34	if ( ! apply_filters( 'jetpack_random_redirect_enabled', true ) ) {
35	return;
36	}
37
38	// Verify that the Random Redirect plugin this code is from is not active
39	// See https://plugins.trac.wordpress.org/ticket/1898
40	if ( ! ( defined( 'IS_WPCOM' ) && IS_WPCOM ) ) {
41	require_once ABSPATH . 'wp-admin/includes/plugin.php';
42	if ( is_plugin_active( 'random-redirect/random-redirect.php' ) ) {
43	return;
44	}
45	}
46
47	// Acceptable URL formats: /[...]/?random=[post type], /?random, /&random, /&random=1
48	if ( ! isset( $_GET['random'] ) && ! ( isset( $_SERVER['REQUEST_URI'] ) && in_array( strtolower( $_SERVER['REQUEST_URI'] ), array( '/&random', '/&random=1' ), true ) ) ) {
49	return;
50	}
51
52	// Ignore POST requests.
53	if ( ! empty( $_POST ) ) {
54	return;
55	}
56
57	// Persistent AppEngine abuse. ORDER BY RAND is expensive.
58	if ( isset( $_SERVER['HTTP_USER_AGENT'] ) && strstr( filter_var( wp_unslash( $_SERVER['HTTP_USER_AGENT'] ) ), 'AppEngine-Google' ) ) {
59	wp_die( 'Please <a href="https://en.support.wordpress.com/contact/" rel="noopener noreferrer" target="_blank">contact support</a>' );
60	}
61
62	$where = array(
63	"post_password = ''",
64	"post_status = 'publish'",
65	);
66	$where_args = array();
67
68	// Set default post type.
69	$post_type = get_post_type();
70
71	// Change the post type if the parameter is set.
72	if ( isset( $_GET['random_post_type'] ) && post_type_exists( sanitize_key( $_GET['random_post_type'] ) ) ) {
73	$post_type = sanitize_key( $_GET['random_post_type'] );
74	}
75
76	// Don't show a random page if 'page' isn't specified as the post type specifically.
77	if ( 'page' === $post_type && is_front_page() && ! isset( $_GET['random_post_type'] ) ) {
78	$post_type = 'post';
79	}
80
81	$where[] = 'p.post_type = %s';
82	$where_args[] = $post_type;
83
84	// Set author name if we're on an author archive.
85	if ( is_author() ) {
86	$where[] = 'post_author = %s';
87	$where_args[] = get_the_author_meta( 'ID' );
88	}
89
90	// Set default category type
91	if ( is_category() ) {
92	$category = get_the_category();
93	if ( isset( $category ) && ! empty( $category ) ) {
94	$random_cat_id = $category[0]->term_id;
95	}
96	}
97
98	// Set the category ID if the parameter is set.
99	if ( isset( $_GET['random_cat_id'] ) ) {
100	$random_cat_id = (int) $_GET['random_cat_id'];
101	}
102
103	global $wpdb;
104
105	$where = implode( ' AND ', $where );
106
107	// Pick a post via COUNT plus a random OFFSET rather than ORDER BY RAND(), which randomizes and sorts every candidate row on each request.
108	if ( isset( $random_cat_id ) ) {
109	$from_where = "FROM $wpdb->posts AS p INNER JOIN $wpdb->term_relationships AS tr ON (p.ID = tr.object_id AND tr.term_taxonomy_id = %s) INNER JOIN $wpdb->term_taxonomy AS tt ON(tr.term_taxonomy_id = tt.term_taxonomy_id AND taxonomy = 'category') WHERE $where";
110	$query_args = array_merge( array( $random_cat_id ), $where_args );
111	} else {
112	$from_where = "FROM $wpdb->posts AS p WHERE $where";
113	$query_args = $where_args;
114	}
115
116	// phpcs:ignore WordPress.DB.DirectDatabaseQuery, WordPress.DB.PreparedSQL.InterpolatedNotPrepared, WordPress.DB.PreparedSQLPlaceholders.ReplacementsWrongNumber, WordPress.DB.PreparedSQLPlaceholders.UnfinishedPrepare
117	$post_count = (int) $wpdb->get_var( $wpdb->prepare( "SELECT COUNT( DISTINCT p.ID ) $from_where", ...$query_args ) );
118
119	if ( $post_count < 1 ) {
120	return;
121	}
122
123	$query_args[] = wp_rand( 0, $post_count - 1 );
124	// phpcs:ignore WordPress.DB.DirectDatabaseQuery, WordPress.DB.PreparedSQL.InterpolatedNotPrepared, WordPress.DB.PreparedSQLPlaceholders.ReplacementsWrongNumber, WordPress.DB.PreparedSQLPlaceholders.UnfinishedPrepare
125	$random_id = $wpdb->get_var( $wpdb->prepare( "SELECT DISTINCT p.ID $from_where ORDER BY p.ID LIMIT 1 OFFSET %d", ...$query_args ) );
126
127	if ( ! $random_id ) {
128	return;
129	}
130
131	// @phan-suppress-next-line PhanTypeMismatchArgument
132	$permalink = get_permalink( $random_id );
133	wp_safe_redirect( $permalink );
134	exit( 0 );
135	}
136
137	add_action( 'template_redirect', 'jetpack_matt_random_redirect' );
138	}
139