Wordpress - wp_insert_post（）和nav_menu_items

Question

I'm using wp_insert_post() to add a new page in WordPress. This inserts the post into wp_posts which in turn makes the post show up in the Dashboard.

From there, I have to manually click and drag under the Pages tab to make that post a menu item in my nav bar,

How can I do this from the PHP side? I've scanned the Codex and can't find what I'm looking for. There doesn't seem to be a WordPress function for that sort of thing.

Answer 1

Problem solved.

While WordPress provides no specific function for adding items and sub-items to the nav bar, there's a workaround. The project involved an author being able to add new books to her database, and have them automatically show up in the nav bar as a sub-item under "Books" without having to go through the Dashboard to do it.

I went to header.php in the theme dir and found the wp_nav_menu() function. After reading this article, I was able to modify the output, using str_replace to add some <li> tags of my own.

This is what the default looked like:

wp_nav_menu( array( 'theme_location' => 'primary' ) );

Here's my modified version:

// First open up a database connection
$db = new MySQLi(DB_HOST, DB_USER, DB_PASSWORD, DB_NAME)

What I did next was basically call up the links (called "guid" in the table) and post titles from "wp_posts" table in the WordPress database. I also needed to get the book names from my own "books" table. The book titles are the same as the "post_title" in "wp_posts".

// Here's the command I used to call them up
$command = 'SELECT b.book_title AS book_title, wp.guid AS guid FROM books AS b
LEFT OUTER JOIN wp_posts AS wp ON b.book_title = wp.post_title
GROUP BY b.order;';

$books_submenu = ''; // leave this empty for now

// Fetch objects from tables
$result = $db->query($command);
while ($data = $result->fetch_object()) {
    $books_submenu = $books_submenu . '
    <li class="menu-item">
    <a href="' . $data->guid . '">' . $data->book_title . '</a>
    </li>'; // Each loop will add another <li> to the variable.

Now comes the part that had me stumped. You can add arguments to the wp_nav_menu function by adding them into the array inside. The important ones I needed were the "theme_location" and "echo". I put all of this in a variable:

$my_new_menu = wp_nav_menu( array( 'theme_location' => 'primary', 'echo' => false ) );

Setting "echo" to false makes the HTML of the function an editable PHP variable. Now we can manipulate it much more easily:

$my_new_menu = str_replace(   '>Books</a></li>', // We're going to replace this...
                              '>Books</a><ul class="sub-menu">' . $books_submenu . '</ul></li>', // ...with this.
                              $my_new_menu
                         );

And finally:

echo $my_new_menu; // Result should be a custom dropdown

That's my end of the work. Every time she adds a new book, my plugin uses wp_post_insert() to add the page to "wp_posts" and adds the book to my "books" table. From there, this script should add that new book to the top of her navigation page :-)