create book navigation menu tree

Question

I have a book with few children article nodes. I would like to create a navigation block tree, that can be placed anywhere on page.

Problem: Normally if I place book navigation block using context (on book and article content type) - the menu shows all links with the link to main book. However, if I try to print inside tpl.php like this

$block = module_invoke('book', 'block_view', 'navigation');
print render($block['content']);

The menu shows only child items. How to show the parent book as well?

Answer 1

This code worked for me:

$blockObject = block_load('book', 'navigation');
    $block = _block_get_renderable_array(_block_render_blocks(array($blockObject)));
    $output = drupal_render($block);
    print $output;