[wp-trac] [WordPress Trac] #49024: Notice: Trying to get property XX of non-object in WP_Query Class

[WordPress Trac]

#49024: Notice: Trying to get property XX of non-object in WP_Query Class
------------------------------+-----------------------------
 Reporter:  agengineering     |      Owner:  (none)
     Type:  defect (bug)      |     Status:  new
 Priority:  normal            |  Milestone:  Awaiting Review
Component:  General           |    Version:
 Severity:  normal            |   Keywords:
  Focuses:  coding-standards  |
------------------------------+-----------------------------
 Hi there,

 sometimes the function
 {{{
 is_page()
 }}}
 return some notice like this:


 {{{
 Notice: Trying to get property ‘ID’ of non-object in
 /home/talabiah/public_html/wp-includes/class-wp-query.php on line 3965

 Notice: Trying to get property ‘post_title’ of non-object in
 /home/talabiah/public_html/wp-includes/class-wp-query.php on line 3967
 }}}

 The reason is that the queried object is null and we use it without any
 kind of check.
 Look here:

 1. First step: call function is_page():

 [[Image(01.png )]]

 wp-includes/query.php:566

 2. is_page call the method is_page() of WP_Query class, look the file wp-
 includes/class-wp-query.php:3952

 {{{
 WP_Query::is_page() call WP_Query::get_queried_object()
 }}}


 [[Image(02.png )]]

 3. get_queired_object() method hae a set of if-elseif but we are not sure
 that the default value:


 {{{
 $this->queried_object    = null;
 }}}

 will be change. There other functions like get_post() or get_userdata()
 that can return null/false value.

 This value will return to WP_Query::is_page()

 [[Image(03.png )]]

 wp-includes/class-wp-query.php:3427

 4. In WP_Query::is_page() there aren't any check if this value is an
 object, but we use it like if we are sure that the get_queried_object()
 can return ONLY an object.

 [[Image(04.png )]]

 I think the best solution is to check if $page_obj is empty or not. A
 solution can be this:

 {{{#!php
 <?php
         /**
          * Is the query for an existing single page?
          *
          * If the $page parameter is specified, this function will
 additionally
          * check if the query is for one of the pages specified.
          *
          * @see WP_Query::is_single()
          * @see WP_Query::is_singular()
          *
          * @since 3.1.0
          *
          * @param int|string|array $page Optional. Page ID, title, slug,
 path, or array of such. Default empty.
          * @return bool Whether the query is for an existing single page.
          */
         public function is_page( $page = '' ) {
                 if ( ! $this->is_page ) {
                         return false;
                 }

                 if ( empty( $page ) ) {
                         return true;
                 }

                 $page_obj = $this->get_queried_object();

                 $page = array_map( 'strval', (array) $page );

                 if ( ! empty( $page_obj ) && in_array( (string)
 $page_obj->ID, $page ) ) {
                         return true;
                 } elseif ( ! empty( $page_obj ) && in_array(
 $page_obj->post_title, $page ) ) {
                         return true;
                 } elseif ( ! empty( $page_obj ) && in_array(
 $page_obj->post_name, $page ) ) {
                         return true;
                 } else {
                         foreach ( $page as $pagepath ) {
                                 if ( ! strpos( $pagepath, '/' ) ) {
                                         continue;
                                 }
                                 $pagepath_obj = get_page_by_path(
 $pagepath );

                                 if ( $pagepath_obj && ( $pagepath_obj->ID
 == $page_obj->ID ) ) {
                                         return true;
                                 }
                         }
                 }

                 return false;
         }
 ?>
 }}}


 Thanks for your attention.


 Pleae note: I have found a similar reporting here:
 [https://core.trac.wordpress.org/ticket/29660 #29660]

-- 
Ticket URL: <https://core.trac.wordpress.org/ticket/49024>
WordPress Trac <https://core.trac.wordpress.org/>
WordPress publishing platform