How are stylesheets and JavaScript loaded in Drupal?
In Drupal 8 and later versions, stylesheets (CSS) and JavaScript (JS) are loaded through the same system for modules (code) and themes, for everything: asset libraries. Asset libraries can contain one or more CSS assets, one or more JS assets and one or more JS settings.
How to add CSS and JavaScript in Drupal?
The stylesheets property (for adding CSS) in THEME. info has been removed and replaced by *. libraries. yml where `*` is the name of the theme or module. The scripts property (for adding JS) in THEME. info has been removed and also replaced by *. libraries. yml where `*` is the name of the theme or module.
Where do JS files come from in Drupal?
You can also have the JS come from an external URL, include CSS files, and there are other possibilities. See CDN / externally hosted libraries for details. However, remember that Drupal no longer loads jQuery on all pages by default; Drupal only loads what’s necessary.
Where do CSS and JS assets go in Drupal?
As you’d expect, the order the CSS and JS assets are listed is also the order in which they will be loaded. By default, Drupal, will attach the JS assets at page bottom to avoid some frequents problems like: DOM content loading block, access to unready DOM element from jquery code, etc…
How to define a library in Drupal 7?
In Drupal 7 libraries had to be defined using hook_library_info(). That has been replaced with *. libraries. yml file. Save the CSS or JS to a file using the proper naming conventions and file structure. Define a “library”, which registers these CSS/JS files with your theme.
How to add jQuery to a Drupal theme?
If your theme requires jQuery or other assets you want to load on all pages, add them in *. libraries. yml. and then include library in the THEME. info. yml. In Drupal 7 libraries had to be defined using hook_library_info().
What kind of library does Drupal use for CSS?
Most themes will use a global- styling asset library, for the stylesheets (CSS files) that need to be loaded on every page where the theme is active. It is also possible to do with JS via a global- scripts asset library