Changing title of a page dynamically from within a plugin

Question

Every WordPress page can be described as having two titles:

1. The page/post title, which is displayed within the page/post via the the_title() function call

2. The html <title></title> tag that displays the title on top of the browser

I am writing a plugin which at one point should change the title of a page dynamically (well, it should change both titles described above).

So, for step 1 above, I found multiple solutions on Stack Overflow (such as this or this). Those are great for only step 1 above.

For step 2, I found this solution; in a nutshell, this is how it works:

add_filter('wp_title', 'change_page_title');
function change_page_title ($title) {

    // Do some magic, and eventually modify $title then return it
    return $title;
}

But the suggested solution is not working for me; and by not working I mean that the filter is not calling the associated function. I am not sure what the problem is; is it because this filter is being called from within the plugin not the theme? (Just FYI, I do not have access to the theme files, so it has to be done from within the plugin).

How can I accomplish this? How can I change the browser title of a page dynamically from within a plugin?

Thanks.

Answer 1

A post or page has only one title, the title tag <title> is the document title.

The filter wp_title filters the output of wp_title() function, which was used before to output the title of the document. In WordPress 4.1, the title-tag support in themes was introduced and wp_get_document_title() is used instead of wp_title(). So, if your theme supports title-tag, wp_title filter has not effect, but you can use a other filters:

pre_get_document_title to set a new title

add_filter( 'pre_get_document_title', 'cyb_change_page_title' );
function cyb_change_page_title () {

    return "Custom title";

}

document_title_separator to filter the title separator

add_filter('document_title_separator', 'cyb_change_document_title_separator');
function cyb_change_document_title_separator ( $sep ) {

    return "|";

}

documente_title_parts to filter different parts of the title: title, page number, tagline and site name.

add_filter( 'document_title_parts', 'cyb_change_document_title_parts' );
function cyb_change_document_title_parts ( $title_parts ) {

    $title_parts['title'] = 'Custom title';
    $title_parts['page'] = 54;
    $title_parts['tagline'] = "Custom tagline";
    $title_parts['site'] = "My Site"; // When not on home page

    return $title_parts;

}

PD: You can use current_theme_supports( 'title-tag' ) to check if theme supports title-tag or not.

Answer 2

Using this code on you page.php or page which you want to change <pre> <title><?php wp_title(); ?> | <?php bloginfo(‘name’); ?></title> </pre>