Custom post type is using the index.php template

Question

Here i read that if i create a custom post type, Wordpress will look to its specific template first, then it falls back to single.php.

I registered a custom post type (i'll show the taxonomy as well), which is properly shown in admin; i can create them well and i've been able to add them to the list of posts in blog's main page. However, when i try to visit its page, i'm not getting a 404 error, but title is not shown in head section and it uses the index.php template, although i have a single.php which is working with common posts and i'd like to use. My new type (in functions.php)

function mytheme_customtypes () {
    $post_args = array(
        'label' => _('Blog Post'),
        'description' => _('Site\'s blog posts'),
        'show_ui' => true,
        'show_in_nav_menus' => true,
        'taxonomies' => array('blog_posts'),
        'supports' => array('title', 'editor', 'comments', 'trackbacks', 'thumbnail'),
        'capability_type' => 'post',
        'rewrite' => array('slug' => 'blog', 'has_archive' => 'blog_posts', 'with_front' => false)
    );

    $tax_args = array(
        'label' => 'Blog posts',
        'description' => _('Raccolta dei post per il blog'),
        'show_ui' => true,
        'show_in_nav_menus' => true,
        'rewrite' => array('slug' => 'blogs',  'with_front' => false),
        'hierarchical' => true
    );

    register_post_type('blog_post', $post_args);

    register_taxonomy('blog_posts', 'blog_post', $tax_args);
}
add_action('init', 'mytheme_customtypes');

Trying to create a new template name single-blog_post.php had no effect. Any help is appreciated

Answer 1

public is false by default, your post type will not be visible on the front end without explicitly setting it to true.

$post_args = array(
    'public' => true,
    'label' => _('Blog Post'),
    'description' => _('Site\'s blog posts'),
    'show_ui' => true,
    'show_in_nav_menus' => true,
    'taxonomies' => array('blog_posts'),
    'supports' => array('title', 'editor', 'comments', 'trackbacks', 'thumbnail'),
    'capability_type' => 'post',
    'rewrite' => array('slug' => 'blog', 'has_archive' => 'blog_posts', 'with_front' => false)
);

Answer 2

I am not sure I follow your question entirely (the bit about "adding" them to the blog). However from your description I think you are missing distinction between archive templates and singular templates.

index.php is catch–all template, it is last fallback for both archives and singular branches of hierarchy.

But before that the logic is different, roughly:

• archive-blog_post.php > archive.php > index.php for archive
• single-blog_post.php > single.php > index.php for singular

So if you are looking at archive of your CPT then any singular templates for it that you have are irrelevant. And other way around.

You would need to create both templates for your CPT if you want to customize both archives and singular entries for it.