How to hide "Navigation" menu as a possible parent menu

Have you checked out the Forms API? http://drupal.org/node/37775

Because, you should be able to do this with a simple module that implements hook_form_alter()
You want to change the array used with $form['menu']['parent']['#options'] to show only the menus you want.

You could also hack into the menu.module itself - see this code from menu_form_alter().

    // Generate a list of possible parents (not including this item or descendants).
    $options = menu_parent_options(menu_get_menus(), $item);
    $default = $item['menu_name'] .':'. $item['plid'];
    if (!isset($options[$default])) {
      $default = 'navigation:0';
    }
    $form['menu']['parent'] = array(
      '#type' => 'select',
      '#title' => t('Parent item'),
      '#default_value' => $default,
      '#options' => $options,
      '#description' => t('The maximum depth for an item and all its children is fixed at !maxdepth.  Some menu items may not be available as parents if selecting them would exceed this limit.', array('!maxdepth' => MENU_MAX_DEPTH)),
      '#attributes' => array('class' => 'menu-title-select'),
    );

Hope that is a little helpful.

I have created a very simple module which allows you to hide the 'Navigation' menu from the 'Menu Settings' drop-down menu on the create/edit content forms.

I am not sure how to go about turning this into a proper module, and to be honest with you the code may not be bomb-proof at all. All I know is that it has been working for me and hopefully it will help someone else out too. Basically, use at your own risk, try it on a development site first before putting it on a live site and fingers crossed it works as well for you as it does for me.

If the following code is wrong or rubbish or massivly flawed please let me know! I am quite nervous to post this here! Can you tell?!

If you follow the instructions below, you should end up with a module which:

• hides the 'Navigation' menu
• allows you to select which of your remaining menus you want to show/hide
• allows you to specify which of your roles you want to be able to see every menu, and which you want to restrict to your settings

Step (1)

Create a directory in your sites/all/modules directory called 'mhn'

Step (2)

Create a file within the mhn directory you've just created called mhn.info
Add this code to it:

name = "Menu Hide Navigation"
description = "A module that hides the navigation menu from the menu settings drop-down in the node create/edit form"

Step (3)

Create a file within the mhn directory called mhn.module
Add this code to it:

<?php

/***** mhn_perm *****/

function mhn_perm() {
	return array('display all menus', 'administer mhn');
} 

/***** mhn_menu *****/

function mhn_menu($may_cache) {
	$items = array();

	$items[] = array(
		'path' => 'admin/build/mhn',
		'title' => t('Menu Hide Navigation Settings'),
		'callback' => 'mhn_admin_settings',
		'access' => user_access('administer mhn'),
		'type' => MENU_NORMAL_ITEM,

	);

	return $items;
}

/***** mhn_admin_settings *****/

function mhn_admin_settings(){
	$content = '<p>'.l('Click here to specify user access control settings for this module', 'admin/user/access').' . You can select which roles will be affected by the following settings.</p><p>The Navigation Menu will always be hidden. You can pick and choose which of the remaining menus you <strong>wish to be visible</strong> on the node create/edit forms:</p>';

	$content .= drupal_get_form(mhn_admin_settings_form);

	return $content;
}

/***** mhn_admin_settings_form *****/
function mhn_admin_settings_form(){

	$result = db_query("SELECT * FROM {menu} WHERE pid < 1");
	
	while($data = db_fetch_object($result)){
		$form['mhn_menus_'.$data->mid] = array(
			'#type' => 'checkbox',
			'#title' => t($data->title),
			'#default_value' => variable_get('mhn_menus_'.$data->mid, 1),
			'#description' => t('Uncheck to hide menu'),
		);
	}

	return system_settings_form($form);
}

/***** mhn_form_alter *****/

function mhn_form_alter($form_id, &$form) {
	if ($form['#id'] == 'node-form' && !user_access('display all menus')) {
		$item = array();
		if ($form['nid']['#value'] > 0) {
			$item = db_fetch_array(db_query("SELECT * FROM {menu} WHERE path = 'node/%d'", $form['nid']['#value']));
			if (isset($form['#post']['menu']) && is_array($form['#post']['menu'])) {
	 			$item = !is_array($item) ? $form['#post']['menu'] : (($form['#post']['op'] == t('Preview')) ? array_merge($item, $form['#post']['menu']) : array_merge($form['#post']['menu'], $item));
			}
		}

		$mhn_arrays = array();
		$options = array();
	
		$result = db_query("SELECT * FROM {menu} WHERE pid < 1");
		while($data = db_fetch_object($result)){
			if(variable_get('mhn_menus_'.$data->mid, 0)){
				$mhn_arrays[] = menu_parent_options($item['mid'], variable_get('menu_parent_items', $data->mid));
			}
		}
	
		foreach($mhn_arrays as $mhn_array){
			while(list($id,$msg) = each($mhn_array)){ 
				$options[$id] = $msg; 
			}
		}
	
		$form['menu']['pid'] = array(
			'#type' => 'select',
			'#title' => t('Parent item'),
			'#default_value' => $item['pid'],
			'#options' => $options,
		);
	}
}

?>

Step (4)

Head to the module page, activate the 'mhn' module and then head to the admin > site building > Menu Hide Navigation Settings page to choose which menus to show/hide. Also head to the admin > users > access contol page to specify which roles you want to be able to see all of the menus.

Thanks!

I need to do the same thing, but inside organic groups (OG).

There is a module called OG Menu that makes it possible for each Organic Group to have its own totally separate menu tree. So I am thinking about modifying the part of the OG module that allow the creation of pages inside the OG. The goal is to make sure that the possible parent items will be limited to the ones that are under a menu that is assigned to the OG itself. If more than one menu is assigned to the OG, then I guess that I will display all of their items as possible parent item.

At first it will be hard coded. Then if the concept works, I will try to see if I can create a separate module that will add this functionnality (with hooks and stuff) without messing with the original OG module.

Does it make sense? Ideas? Advices?

Cheers