Is there a way to read or list wp_head() contents?

Question

I am working on a CSS and JS compiler and need to find a way to list the contents of wp_head()

I am trying to get a list of all CSS/JS files and inline CSS on any give page.

Hooking on the wp_head action does not do anything

I was hoping that something like this would work

function head_content($list){

    print_r($list);


}

add_action('wp_head', 'head_content');

any help is appreciated.

UPDATE:

got something working

function head_content($list){

    print_r($list);

    return $list;

}

add_filter('print_styles_array', 'head_content');
add_filter('print_script_array', 'head_content');

this lists all css/js files handles

Answer 1

I wanted to search-and-replace in the header, but Neither @majick or @Samuel Elh answers worked for me directly. So, combining their answers I got what eventually works:

function start_wp_head_buffer() {
    ob_start();
}
add_action('wp_head','start_wp_head_buffer',0);

function end_wp_head_buffer() {
    $in = ob_get_clean();

    // here do whatever you want with the header code
    echo $in; // output the result unless you want to remove it
}
add_action('wp_head','end_wp_head_buffer', PHP_INT_MAX); //PHP_INT_MAX will ensure this action is called after all other actions that can modify head

It was added to functions.php of my child theme.

Answer 2

Simple solution is to listen for wp_head in a custom function, just like WordPress does in wp-includes/general-template.php for wp_head() function.

I mean something like:

function head_content() {
    ob_start();
    do_action('wp_head');
    return ob_get_clean();
}
// contents
var_dump( head_content() );

Later, use regex or other tool to filter the contents you are targeting..

Hope that helps.

Answer 3

You could buffer the wp_head output by adding some wrapper actions to it:

add_action('wp_head','start_wp_head_buffer',0);
function start_wp_head_buffer() {ob_start;}
add_action('wp_head','end_wp_head_buffer',99);
function end_wp_head_buffer() {global $wpheadcontents; $wpheadcontents = ob_get_flush();}

You can then call global $wpheadcontents; elsewhere to access the content and process it.

But, in this case, it may be simpler to just get the information you are looking for directly from the global $wp_styles and $wp_scripts variables.

function print_global_arrays() {
    global $wp_styles, $wp_scripts;
    echo "Styles Array:"; print_r($wp_styles);
    echo "Scripts Array:"; print_r($wp_scripts);
}
add_action('wp_enqueue_scripts','print_global_arrays',999);