Wrong post ID in meta box callback

Question

I trying to get the ID of the post on edit page but its displaying the wrong ID

Custom Post:

register_post_type( 'projetos', array(
    'description'           => 'Projetos do Scan'
    ,'exclude_from_search'  => false
    ,'public'               => true
    ,'publicly_queryable'   => true
    ,'show_ui'              => true
    ,'show_in_menu'         => true
    ,'query_var'            => true
    ,'rewrite'              => array( 'slug' => 'projeto' )
    ,'capability_type'      => 'post'
    ,'has_archive'          => true
    ,'menu_position'        => 20
    ,'supports'             => array( 'title', 'editor' )
    ,'hierarchical'         => true
    ,'labels' => array(
        'name'               => _x( 'Projetos', 'post type general name', 'Projetos do Scan' ),
        'singular_name'      => _x( 'Projeto', 'post type singular name', 'Projetos do Scan' ),
        'menu_name'          => _x( 'Projetos', 'admin menu', 'Projetos do Scan' ),
        'name_admin_bar'     => _x( 'Projeto', 'add new on admin bar', 'Projetos do Scan' ),
        'add_new'            => _x( 'Adicionar Novo', 'foto', 'Projetos do Scan' ),
        'add_new_item'       => __( 'Adicionar Novo Projeto', 'Projetos do Scan' ),
        'new_item'           => __( 'Novo Projeto', 'Projetos do Scan' ),
        'edit_item'          => __( 'Editar Projeto', 'Projetos do Scan' ),
        'view_item'          => __( 'Ver Projeto', 'Projetos do Scan' ),
        'all_items'          => __( 'Todos os Projetos', 'Projetos do Scan' ),
        'search_items'       => __( 'Buscar Projetos', 'Projetos do Scan' ),
        'parent_item_colon'  => __( 'Projetos:', 'Projetos do Scan' ),
        'not_found'          => __( 'Nenhum projeto encontrado.', 'Projetos do Scan' ),
        'not_found_in_trash' => __( 'Nenhum projeto encontrado na lixeira.', 'Projetos do Scan' )
    )
    ,'menu_icon' => 'dashicons-clipboard'
    ,'register_meta_box_cb' => 'projetos_meta_box' // adicionar meta boxes e remover meta boxes neste callback
) );

Callback:

function projetos_meta_box() {
add_meta_box('projetos_info_meta_box', 'Informações', 'render_projetos_info_meta_box', 'projetos', 'side', 'default');
add_meta_box('projetos_imagens_meta_box', 'Imagens', 'render_projetos_imagens_meta_box', 'projetos', 'normal', 'default');
add_meta_box('projetos_capitulos_meta_box', 'Capítulos', 'render_projetos_capitulos_meta_box', 'projetos', 'normal', 'default');

}

and here's the problem

function render_projetos_imagens_meta_box( $post ) {
global $post;

wp_nonce_field( 'projetos_imagens_meta_box', 'projetos_imagens_meta_box');
$imagens_projeto = json_decode( get_post_meta( $post->ID, 'imagens_projeto', true ) );

ob_start(); ?>

<?php echo var_dump($post); ?>
<div style="margin-top: 10px;">
    <button type="button" id="btn_add_img" class="button button-primary button-large">Adicionar</button>
</div>
<ul class="attachments-projeto">
<?php if( !empty( $imagens_projeto ) ) : foreach( $imagens_projeto as $img_pjt ) : ?>

    <li>
        <button data-id="<?php echo $img_pjt->id; ?>" type="button" class="btn_remover_img">
            <span class="dashicons dashicons-trash"></span>
        </button>
        <img alt="<?php echo $img_pjt->title; ?>" src="<?php echo $img_pjt->url; ?>" />
    </li>

<?php endforeach; endif; ?>
</ul>
<div class="clearfix"></div>
<input type="hidden" id="imagens_projeto" name="imagens_projeto" value="<?php echo get_post_meta( $post->ID, 'imagens_projeto', true ); ?>" />

<?php
echo ob_get_clean();

}

Answer 1

If you remove the line global $post; (and really you should remove it), there is no reason this shouldn't work, according to the official documentation, unless as @rudtek mentioned, you run a custom query somewhere and the $post has changed

Answer 2

I think your problem come from the json_decode. It's look like the get_post_meta returns you a member data (post_type->membros on the bottom var_dump) !

Have a look on the code to save this meta.

Answer 3

Since I cannot solve the problem I did a workaround to this

$post_id = intval($_GET['post']);

Basically I getting the post ID from the edit post url