WordPress using different CSS - is this possible?

Question

Bit is a basic question here but can someone confirm that this statement be confirmed: WordPress Pages (certain templates created within) can pull different CSS and JS?

Or - does WordPress only permit universal CSS + JS to be pulled across the entire site?

Thanks for clearing this up.

Answer 1

Depends on what plugin and themes you use. The WordPress/PHP functions wp_enqueue_style() and wp_enqueue_script() can be used literally by everyone (core, themes, plugins, you) to request WordPress to load styles or JavaSctript. You can combine this with WordPress functions to check whether the current page is something you want to filter for (post type, post, front-page, category archive, template, etc.). Here is an example to load a custom style if on front page :

if (is_front_page()) {
    wp_enqueue_style('custom-frontpage', 'my/path/to/frontpage.css');
}

You will have to hook this piece of code to the wp_enqueue_script action so that WordPress executes it at the appropriate time. Here is an example using an anonymous function:

add_action('wp_enqueue_scripts', function() {
    if (is_front_page())
        wp_enqueue_style('custom-frontpage', 'my/path/to/frontpage.css');
});

You can also register your code as a "normal" function and pass the functions name to add_action() instead.

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Edit: Enabling and disabling plugins is a bit more difficult, since you can never know how they implement their features without examining the source code. Here are my thoughts on this:

The plugin likely uses the above method (wp_enqueue_styles, wp_enqueue_scripts) to register it's styles and scripts. The plugin, since it assumes to be needed on all pages and posts, does this on every page without the conditional checking described earlier.

You could do one of the following to stop the plugin from doing this:

1. Identify the place where the plugin loads the styles and scripts and add the if-statement to only do so if the post-ID matches your desired post-ID. This method is bad since your changes are lost every time the plugin is updated.

2. Write a "counter plugin" (you could just add it to your theme or find a plugin that allowes you to add PHP to your page) that "dequeues" the style and script added by the plugin with inversed conditional tag

The counter-plugin approach would look as follows:

function custom_unregister_plugin() {
    if (not the desired blog post) {
        wp_dequeue_style('my-plugin-stylesheet-handle');
        wp_dequeue_script('my-plugin-script-handle');
    }
}

Make sure this function is executed after the enqueuing-code of your plugin by giving it a low priority in the same hook (999 is just an example, test it yourself):

add_action('wp_enqueue_scripts', 'custom_unregister_plugin', 999);

Answer 2

You can use wp_enqueue_style for your CSS, wp_enqueue_script for your JS, wp_localize_script to pass variables from PHP to JS.

You can call these with hooks like:

funtion enqueue_my_stuff()
{
// your enqueue function calls
}
add_action('wp_enqueue_scripts','enqueue_my_stuff'); //front end 
add_action('admin_enqueue_scripts','enqueue_my_stuff'); //admin panel
add_action('login_enqueue_scripts','enqueue_my_stuff'); //login screen

Answer 3

With wp_enqueue_style() you can add stylesheet (https://developer.wordpress.org/reference/functions/wp_enqueue_style/)

You can use it after detecting which template is used

function enqueue_custom_stylesheet() {
    if(get_page_template() == 'contact.php')
          wp_enqueue_style( 'contact-style', get_template_directory_uri().'/contact.css' );
}
add_action( 'wp_enqueue_scripts', 'enqueue_custom_stylesheet' );