I have below code when developing theme to reach upper array keys and value. Use {{image-about}} to reach attachments array first key 'image-about' => ...

  add_theme_support( 'starter-content', [
        'widgets'                           => [
            // Place three core-defined widgets in the sidebar area
            'ju_sidebar'                    => [
                'text_business_info', 'search', 'text_about',
                ]
            ],

            // Create the custom image attachments used as post thumbnails for pages
            'attachments'                    => [
                'image-about'                => [
                    'post_title'             => __('About','udemy'),
                    'file'                   => 'assets/images/about/1.jpg',
                    ],
            ],
            'posts'                          => [
                'home'                       => [
                    'thumbnail'              => '{{image-about}}'
                    ], 
                'about'                      => [
                    'thumbnail'              => '{{image-about}}'
                    ], 
                'contact'                    => [
                    'thumbnail'              => '{{image-about}}'
                    ], 
                'blog'                       => [
                    'thumbnail'              => '{{image-about}}'
                    ], 
                'homepage-section'           => [
                    'thumbnail'              => '{{image-about}}'
                    ],
            ],
            'options'                        => [
                'show_on_front'              => 'page',
                'page_on_front'              => '{{home}}',
                'page_for_posts'             => '{{blog}}',
            ],
            'theme_mods'                     => [
                'ju_facebook_handle'         => 'udemy',
                'ju_twitter_handle'          => 'udemy',
                'ju_instagram_handle'        => 'udemy',
                'ju_email'                   => 'udemy',
                'ju_phone_number'            => 'udemy',
                'ju_header_show_search'      => 'yes',
                'ju_header_show_cart'        => 'yes',
            ],
            'nav_menus'                      => [
                'primary'                    => array(
                    'name'                   => __('Primary Menu','udemy'),
                    'items'                  => array(
                        'link_home',
                        'page_about',
                        'page_block',
                        'page_contact',
                    ),
                ),
                'secondary'                    => array(
                    'name'                   => __('Secondary Menu','udemy'),
                    'items'                  => array(
                        'link_home',
                        'page_about',
                        'page_block',
                        'page_contact',
                    ),
                ),
            ]
    ]);

I couldn't find any response related to those double curly braces. Only find for wp.customize javascript notation or angular.js but none of them explains this situation.

Any information about that would be very helpful

I have below code when developing theme to reach upper array keys and value. Use {{image-about}} to reach attachments array first key 'image-about' => ...

  add_theme_support( 'starter-content', [
        'widgets'                           => [
            // Place three core-defined widgets in the sidebar area
            'ju_sidebar'                    => [
                'text_business_info', 'search', 'text_about',
                ]
            ],

            // Create the custom image attachments used as post thumbnails for pages
            'attachments'                    => [
                'image-about'                => [
                    'post_title'             => __('About','udemy'),
                    'file'                   => 'assets/images/about/1.jpg',
                    ],
            ],
            'posts'                          => [
                'home'                       => [
                    'thumbnail'              => '{{image-about}}'
                    ], 
                'about'                      => [
                    'thumbnail'              => '{{image-about}}'
                    ], 
                'contact'                    => [
                    'thumbnail'              => '{{image-about}}'
                    ], 
                'blog'                       => [
                    'thumbnail'              => '{{image-about}}'
                    ], 
                'homepage-section'           => [
                    'thumbnail'              => '{{image-about}}'
                    ],
            ],
            'options'                        => [
                'show_on_front'              => 'page',
                'page_on_front'              => '{{home}}',
                'page_for_posts'             => '{{blog}}',
            ],
            'theme_mods'                     => [
                'ju_facebook_handle'         => 'udemy',
                'ju_twitter_handle'          => 'udemy',
                'ju_instagram_handle'        => 'udemy',
                'ju_email'                   => 'udemy',
                'ju_phone_number'            => 'udemy',
                'ju_header_show_search'      => 'yes',
                'ju_header_show_cart'        => 'yes',
            ],
            'nav_menus'                      => [
                'primary'                    => array(
                    'name'                   => __('Primary Menu','udemy'),
                    'items'                  => array(
                        'link_home',
                        'page_about',
                        'page_block',
                        'page_contact',
                    ),
                ),
                'secondary'                    => array(
                    'name'                   => __('Secondary Menu','udemy'),
                    'items'                  => array(
                        'link_home',
                        'page_about',
                        'page_block',
                        'page_contact',
                    ),
                ),
            ]
    ]);

I couldn't find any response related to those double curly braces. Only find for wp.customize javascript notation or angular.js but none of them explains this situation.

Any information about that would be very helpful

• php
• theme-development

• This appears to be code from a theme or plugin purchased from Udemy? My guess is that the content in {{...}} is placeholder text, meant to be replaced by some function or other, but your best bet is to check with Udemy's help streams. – Pat J Commented Apr 30, 2020 at 13:58
• Yes, this is sample theme from udemy. But those theme support starter is pre-built wordpress functionality which leads to display default content on customization panel opened. So, actually those double curly braces pointed out the upper array's key and value to be replaced. – O.k Commented Apr 30, 2020 at 14:15

1 Answer 1

In your example {{image-about}} tells WordPress to use the image defined in ['attachments']['image-about'] as the thumbnail for those posts in the 'starter content'. This functionality is specific to the "Starter Content" feature added in WordPress 4.7, which is described here, and not a PHP language feature.