Wp custom plugins meta filed box are not visible - wordpress

Question

I have created a plugins about to save Authorz data using wordpress custom fields and meta box. The Plugins has no errors and running but the Meta boxes are not showing.
The plugins is running and i have attached the screenshot.
http://i63.tinypic.com/2czebyh.png
Below is my plugin code
<?php
/*Plugin Name: CNSLounge
Description: This plugin registers the 'Authors CNSLounge' post type.
Version: 1.0
Author: Anita Mandal
Author URI: http://cosmoread.com/
License: GPLv2
*/
// Register Custom Post Type
function CNSLounge() {
register_post_type('CNSLounge', array(
'labels' => array(
'name' => 'Authorz',
'singular_name' => 'Authorz',
'add_new' => 'Add New',
'add_new_item' => 'Add New Authorz',
'edit' => 'Edit',
'edit_item' => 'Edit Authorz',
'new_item' => 'New Authorz',
'view' => 'View',
'view_item' => 'View Authorz',
'search_items' => 'Search Authorz',
'not_found' => 'No Authorz found',
'not_found_in_trash' => 'No Authorz found in Trash',
'parent' => 'Parent Authorz'
),
'public' => true,
'menu_position' => 15,
'supports' => array(
'title',
'editor',
'comments',
'thumbnail'
),
'taxonomies' => array(
''
),
'menu_icon' => plugins_url('images/image.png', __FILE__),
'has_archive' => true
));
register_post_type( 'post_type', $args );
}
add_action( 'init', 'CNSLounge', 0 );
class Rational_Meta_Box {
private $screens = array(
'post',
);
private $fields = array(
array(
'id' => 'authorz-name',
'label' => 'Authorz Name',
'type' => 'text',
),
array(
'id' => 'author-photo',
'label' => 'Author Photo',
'type' => 'media',
),
array(
'id' => 'active-since',
'label' => 'Active Since',
'type' => 'date',
),
array(
'id' => 'languages-expression',
'label' => 'Languages Expression',
'type' => 'text',
),
array(
'id' => 'now-based-at',
'label' => 'Now Based at',
'type' => 'text',
),
array(
'id' => 'location-of-author',
'label' => 'Location of Author',
'type' => 'text',
),
array(
'id' => 'mostly-writes',
'label' => 'Mostly Writes',
'type' => 'text',
),
array(
'id' => 'about-author',
'label' => 'About Author',
'type' => 'textarea',
),
array(
'id' => 'magazines',
'label' => 'Magazines',
'type' => 'media',
),
array(
'id' => 'publication',
'label' => 'Publication',
'type' => 'media',
),
array(
'id' => 'gallery',
'label' => 'Gallery',
'type' => 'media',
),
array(
'id' => 'author-s-website',
'label' => 'Author\'s Website',
'type' => 'url',
),
array(
'id' => 'author-s-email',
'label' => 'Author\'s Email',
'type' => 'email',
),
array(
'id' => 'author-s-phone',
'label' => 'Author\'s Phone',
'type' => 'number',
),
);
/**
* Class construct method. Adds actions to their respective WordPress hooks.
*/
public function __construct() {
add_action( 'add_meta_boxes', array( $this, 'add_meta_boxes' ) );
add_action( 'admin_footer', array( $this, 'admin_footer' ) );
add_action( 'save_post', array( $this, 'save_post' ) );
}
/**
* Hooks into WordPress' add_meta_boxes function.
* Goes through screens (post types) and adds the meta box.
*/
public function add_meta_boxes() {
foreach ( $this->screens as $screen ) {
add_meta_box(
'cnslounge',
__( 'CNSLounge', 'rational-metabox' ),
array( $this, 'add_meta_box_callback' ),
$screen,
'advanced',
'default'
);
}
}
/**
* Generates the HTML for the meta box
*
* #param object $post WordPress post object
*/
public function add_meta_box_callback( $post ) {
wp_nonce_field( 'cnslounge_data', 'cnslounge_nonce' );
echo 'CNSLounge Author Meta Information';
$this->generate_fields( $post );
}
/**
* Hooks into WordPress' admin_footer function.
* Adds scripts for media uploader.
*/
public function admin_footer() {
?><script>
// https://codestag.com/how-to-use-wordpress-3-5-media-uploader-in-theme-options/
jQuery(document).ready(function($){
if ( typeof wp.media !== 'undefined' ) {
var _custom_media = true,
_orig_send_attachment = wp.media.editor.send.attachment;
$('.rational-metabox-media').click(function(e) {
var send_attachment_bkp = wp.media.editor.send.attachment;
var button = $(this);
var id = button.attr('id').replace('_button', '');
_custom_media = true;
wp.media.editor.send.attachment = function(props, attachment){
if ( _custom_media ) {
$("#"+id).val(attachment.url);
} else {
return _orig_send_attachment.apply( this, [props, attachment] );
};
}
wp.media.editor.open(button);
return false;
});
$('.add_media').on('click', function(){
_custom_media = false;
});
}
});
</script><?php
}
/**
* Generates the field's HTML for the meta box.
*/
public function generate_fields( $post ) {
$output = '';
foreach ( $this->fields as $field ) {
$label = '<label for="' . $field['id'] . '">' . $field['label'] . '</label>';
$db_value = get_post_meta( $post->ID, 'advanced_options_' . $field['id'], true );
switch ( $field['type'] ) {
case 'media':
$input = sprintf(
'<input class="regular-text" id="%s" name="%s" type="text" value="%s"> <input class="button rational-metabox-media" id="%s_button" name="%s_button" type="button" value="Upload" />',
$field['id'],
$field['id'],
$db_value,
$field['id'],
$field['id']
);
break;
case 'textarea':
$input = sprintf(
'<textarea class="large-text" id="%s" name="%s" rows="5">%s</textarea>',
$field['id'],
$field['id'],
$db_value
);
break;
default:
$input = sprintf(
'<input %s id="%s" name="%s" type="%s" value="%s">',
$field['type'] !== 'color' ? 'class="regular-text"' : '',
$field['id'],
$field['id'],
$field['type'],
$db_value
);
}
$output .= $this->row_format( $label, $input );
}
echo '<table class="form-table"><tbody>' . $output . '</tbody></table>';
}
/**
* Generates the HTML for table rows.
*/
public function row_format( $label, $input ) {
return sprintf(
'<tr><th scope="row">%s</th><td>%s</td></tr>',
$label,
$input
);
}
/**
* Hooks into WordPress' save_post function
*/
public function save_post( $post_id ) {
if ( ! isset( $_POST['cnslounge_nonce'] ) )
return $post_id;
$nonce = $_POST['cnslounge_nonce'];
if ( !wp_verify_nonce( $nonce, 'cnslounge_data' ) )
return $post_id;
if ( defined( 'DOING_AUTOSAVE' ) && DOING_AUTOSAVE )
return $post_id;
foreach ( $this->fields as $field ) {
if ( isset( $_POST[ $field['id'] ] ) ) {
switch ( $field['type'] ) {
case 'email':
$_POST[ $field['id'] ] = sanitize_email( $_POST[ $field['id'] ] );
break;
case 'text':
$_POST[ $field['id'] ] = sanitize_text_field( $_POST[ $field['id'] ] );
break;
}
update_post_meta( $post_id, 'cnslounge_' . $field['id'], $_POST[ $field['id'] ] );
} else if ( $field['type'] === 'checkbox' ) {
update_post_meta( $post_id, 'cnslounge_' . $field['id'], '0' );
}
}
}
}
new Rational_Meta_Box;
?>

Answer 1

private $screens = array(
'post',
);
So, you are adding the metaboxes to post, not to your custom post type.
Use your custom post type slug here. just like
private $screens = array(
'CNSLounge',
);