plugin development - add_action not calling back to function

I am working on a plugin, but add_action doesn't call the callback. The code is as follows:

require plugin_dir_path( __FILE__ ) . 'includes/class-network.php';

$distro = new Classnetwork();

includes/class-network.php:

class Classnetwork {
    public function __construct() {
        add_action( 'publish_post', array ($this, 'cdn_capture_data') );
    }

    public function cdn_capture_data( $post_id, $post ) {
        print_r ($post);            
}
}

Nothing is printed, not error, it just doesn't do anything every time I post a new post. Any ideas where is the error? The __construction is called but not the callback from add_action.

I am working on a plugin, but add_action doesn't call the callback. The code is as follows:

require plugin_dir_path( __FILE__ ) . 'includes/class-network.php';

$distro = new Classnetwork();

includes/class-network.php:

class Classnetwork {
    public function __construct() {
        add_action( 'publish_post', array ($this, 'cdn_capture_data') );
    }

    public function cdn_capture_data( $post_id, $post ) {
        print_r ($post);            
}
}

Nothing is printed, not error, it just doesn't do anything every time I post a new post. Any ideas where is the error? The __construction is called but not the callback from add_action.

• plugin-development
• actions

Share Improve this question asked Dec 10, 2018 at 9:27 GonzaloGonzalo 16722 silver badges1010 bronze badges 2

• set define('WP_DEBUG', false); to define('WP_DEBUG', true); in wp-config.php file @Greg Winiarski, answer should do the job. You didn't specify the execution order and default number of arguments If you didn't specify them, they default to 10 and 1 ( in your case you passed two arguments to function attached to hook ) – maverick Commented Dec 10, 2018 at 11:03
• @maverick you were right, the issue was that I didn't indicate the how many parameters. Thanks – Gonzalo Commented Dec 10, 2018 at 15:14

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1 Answer 1

Sorted by: Reset to default 1

I understand that you are adding the post from wp-admin / Posts / Add New panel? If so then note that the publish_post action is run and the WP is doing redirect so you cannot see any printed data.

Also, your add_action call is missing 4th argument which is number of arguments passed to cdn_capture_data(), by default there is only 1 argument passed so in your case the $post is always null.

The correct code (to actually print the result) should be

class Classnetwork {
    public function __construct() {
        add_action( 'publish_post', array ($this, 'cdn_capture_data'), 10, 2 );
    }

    public function cdn_capture_data( $post_id, $post ) {
        print_r ($post);  
        exit;          
    }
}