summaryrefslogtreecommitdiff
blob: 19c0f2208c8af109c060a662f027713dc9041fb5 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
<?php

/**
 * Allows viewing posts on the frontend when the user is not logged in.
 */
class Jetpack_Frame_Nonce_Preview {
	static $instance = null;

	/**
	 * Returns the single instance of the Jetpack_Frame_Nonce_Preview object
	 *
	 * @since 4.3.0
	 *
	 * @return Jetpack_Frame_Nonce_Preview
	 **/
	public static function get_instance() {
		if ( ! is_null( self::$instance ) ) {
			return self::$instance;
		}

		return self::$instance = new Jetpack_Frame_Nonce_Preview();
	}

	function __construct() {
		if ( isset( $_GET['frame-nonce'] ) && ! is_admin() ) {
			add_filter( 'pre_get_posts', array( $this, 'maybe_display_post' ) );
		}

		// autosave previews are validated differently
		if ( isset( $_GET[ 'frame-nonce' ] ) && isset( $_GET[ 'preview_id' ] ) && isset( $_GET[ 'preview_nonce' ] ) ) {
			remove_action( 'init', '_show_post_preview' );
			add_action( 'init', array( $this, 'handle_autosave_nonce_validation' ) );
		}
	}

	/**
	 * Verify that frame nonce exists, and if so, validate the nonce by calling WP.com.
	 *
	 * @since 4.3.0
	 *
	 * @return bool
	 */
	public function is_frame_nonce_valid() {
		if ( empty( $_GET[ 'frame-nonce' ] ) ) {
			return false;
		}

		Jetpack::load_xml_rpc_client();
		$xml = new Jetpack_IXR_Client();
		$xml->query( 'jetpack.verifyFrameNonce', sanitize_key( $_GET['frame-nonce'] ) );

		if ( $xml->isError() ) {
			return false;
		}

		return (bool) $xml->getResponse();
	}

	/**
	 * Conditionally add a hook on posts_results if this is the main query, a preview, and singular.
	 *
	 * @since 4.3.0
	 *
	 * @param WP_Query $query
	 *
	 * @return WP_Query
	 */
	public function maybe_display_post( $query ) {
		if (
			$query->is_main_query() &&
			$query->is_preview() &&
			$query->is_singular()
		) {
			add_filter( 'posts_results', array( $this, 'set_post_to_publish' ), 10, 2 );
		}

		return $query;
	}

	/**
	 * Conditionally set the first post to 'publish' if the frame nonce is valid and there is a post.
	 *
	 * @since 4.3.0
	 *
	 * @param array $posts
	 *
	 * @return array
	 */
	public function set_post_to_publish( $posts ) {
		remove_filter( 'posts_results', array( $this, 'set_post_to_publish' ), 10, 2 );

		if ( empty( $posts ) || is_user_logged_in() || ! $this->is_frame_nonce_valid() ) {
			return $posts;
		}

		$posts[0]->post_status = 'publish';

		// Disable comments and pings for this post.
		add_filter( 'comments_open', '__return_false' );
		add_filter( 'pings_open', '__return_false' );

		return $posts;
	}

	/**
	 * Handle validation for autosave preview request
	 *
	 * @since 4.7.0
	 *
	 */
	public function handle_autosave_nonce_validation() {
		if ( ! $this->is_frame_nonce_valid() ) {
			wp_die( __( 'Sorry, you are not allowed to preview drafts.', 'jetpack' ) );
		}
		add_filter( 'the_preview', '_set_preview' );
	}
}

Jetpack_Frame_Nonce_Preview::get_instance();