Use Carbon Fields in an included plugin file

Question

I am using the Carbon Fields plugin (not composer). I am building a large site and will have many functions to add fields to lots of different pages. I don't like to have extremely long files that make it harder to find the code for each page. If everything is in the main plugin file, it works fine. But if I try to require_once() or include() another file that contains Carbon Fields classes, I get the error: "class Container not found".

Is there a way to get the classes to be available in included files instead of everything having to be in the main file? I have searched the documentation and can find nothing on this.

Answer 1

Finally figured this out for anyone else running into an issue. Each included file that requires Carbon Fields classes must have the following at the beginning of the file:

require_once(WP_PLUGIN_DIR . '/carbon-fields/carbon-fields-plugin.php');

use Carbon_Fields\Container;
use Carbon_Fields\Field;

After this, you can start your functions and such. I am adding some additional coding on the extension plugin file to ensure the Carbon Fields plugin is activated to keep things from breaking.

Answer 2

You can include your file directly in functions.php like this (after installing the plugin):

require_once get_template_directory() . '/assets/inc/your-file.php';

Just replace /assets/inc/ with your folder structure.

I'm guessing your real issue is not invoking a Container::make before calling Field::make and the reason you received the class error.

In other words, something like this would go in your included file:

use Carbon_Fields\Container;
use Carbon_Fields\Field;

Container::make( 'post_meta', __( 'Page Options', 'crb' ) )
    ->where( 'post_type', '=', 'page' ) // only show our new fields on pages
    ->add_fields( array(
        Field::make( 'complex', 'slider', 'Slides' )
            ->set_layout( 'tabbed-horizontal' )
            ->add_fields( array(
                Field::make( 'text', 'slider_title', __( 'Slide Title' ) ),
                Field::make( 'image', 'slider_media', __( 'Slide Media' ) )
                    ->set_type( array( 'image', 'video' ) )
            ) ),
    ) );

The Container class must be called before the Field class or you will get the error you mentioned.