[Resuelto] 48 Render blocking scripts.

Many scripts are declared as dependencies of jQuery, so the "simplest" solution seems to be to move jQuery so that it is added in the footer rather than the header, which will take all of its dependencies with it, meaning few if any scripts appearing in the head and giving you the warning about render-blocking scripts.

I went round and round in circles trying solutions to change jQuery so that it is moved to the footer, before reading that it is essentially impossible since WordPress 3.9, meaning that the many "solutions" still available on line mostly won't work.

I did stumble across a somewhat blunt-instrument approach, which appears to work.

Namely, you remove the hooks which are used to add scripts to the head.

If they don't get added to the head, they get added to the footer, which is what we're looking for.

Here's the code you can use:

function tssupp_brute_force_footer_scripts() {
    remove_action('wp_head', 'wp_print_scripts');
    remove_action('wp_head', 'wp_print_head_scripts', 9);
    remove_action('wp_head', 'wp_enqueue_scripts', 1);
}
add_action('wp_enqueue_scripts', 'tssupp_brute_force_footer_scripts');

There is one drawback with this method.

Any inline script tags that appear in the body will be parsed before jQuery is enqueued, so may need tweaking to work on the document ready event before relying on jQuery. If you are not adding any custom JS then you would hopefully not run into the problem, except...

the way custom CSS that you add to Views editors is handled involves inline JS which does depend on jQuery, so it rules out you adding and custom CSS via the Views editors, you would need another solution.

Again, I'm just tidying up my queue, so let me mark this as awaiting feedback.

There is a general problem with Toolset assets in that when building the page on the server it is not known what's needed until building the page is almost complete, because Views, maps, forms etc., could all be added in the page footer. Hence Toolset tends to enqueue the key assets that might be required on the page.

It's not easy to do much about the stylesheets because CSS should be loaded in the head, but we could improve the situation for scripts.

It has been looked at before but is not being currently worked on, and so if you want it to be prioritised you should submit a request at https://toolset.com/home/contact-us/suggest-a-new-feature-for-toolset/

The alternative is go through the list of styles and scripts added to your pages on the front end one by one and dequeue them on pages where you know they are not needed (using https://developer.wordpress.org/reference/functions/wp_dequeue_script/).

We don't have a categoric list of which assets are needed where, and so it might require some trial and error on your part.

But I do recommend you submit that request.

I just ran a quick test, checking the scripts which are loaded when viewing the Sample Page (no Toolset content) on a new WordPress site that has Toolset Types, Views, Forms and Maps active.

In screenshot 1 you can see there are 19 scripts loaded on the page (vs 3 when there are no plugins active).

Let's say I want to dequeue the "wpv-pagination-embedded.js" script.

To do that, I need to know the "handle" that was used to enqueue it.

I can check that for any script by dumping the global $wp_scripts object to my debug log from a suitable hook, e.g.

function custom_scripts( ){

	global $wp_scripts;

	error_log('wp_scripts: ' . print_r($wp_scripts, true));
}
add_action( 'wp_print_scripts', 'custom_scripts', 9999 );

Here's what I find for the pagination script:

            [views-pagination-script] => _WP_Dependency Object
                (
                    [handle] => views-pagination-script
                    [src] => <em><u>enlace oculto</u></em>
                    [deps] => Array
                        (
                            [0] => jquery
                            [1] => jquery-ui-datepicker
                            [2] => wp-mediaelement
                            [3] => wp-playlist
                            [4] => underscore
                        )

                    [ver] => 2.8.1
...
                )

The handle I need is "views-pagination-script". Note that it has several dependencies. If no other enqueued scripts have these dependencies, the dequeueing this script should also drop those.

So let's try with

function custom_scripts( ){

	global $wp_scripts;

	wp_dequeue_script( 'views-pagination-script' );
}
add_action( 'wp_print_scripts', 'custom_scripts', 9999 );

You can see the results in screenshot 2, where we now have just 12 scripts loaded. So because its dependencies may have dependencies, getting rid of the pagination script actually removed unnecessary 7 scripts.

You can continue in the same vein removing other scripts added by Toolset that you know are not needed.

And, of course, you need to be adding conditions, to only remove the assets on pages where you know they are not needed.

I've set myself a task to do some further testing and then document the results as a reference until such time as it can be controlled in through the settings.