How to add one another library files with different name from the theme name?

Question

I try to define a separate library with different name from the theme name, according to this artcle:
Adding stylesheets (CSS) and JavaScript (JS) to a Drupal 8 theme
For example a library with below details:

• Theme name: MyThemeName
• Library Name: Library A
• Library File Name: libfile.info.yml

libfile.libraries.yml

LibraryA:
  version: 1.x
  css:
    theme:
      css/Style.css: {}

And then attach this library to all page in:

MyThemeName.info.yml

libraries:
  - MyThemeName/LibraryA

I would be happy to hear what the problem is, share your experiences and guide me to know what is the right way to add another library files with different name from the MyThemeName?
Thanks for any help.

Answer 1

Short answer: You cannot.

Looking answer: The purpose to for the libraries file is too define all the libraries of a module / theme.

The file is recognized because it is has the name of the theme/module it is placed at.

If you want libraries with a different namespace then you will need to search for an alter hook, and define these libraries there (not recommended).

Answer 2

You're reading the module docs, the theme docs are here. The advice is identical for both though:

To define one or more (asset) libraries, add a *.libraries.yml file to your theme folder. (If your theme is named fluffiness, then the file name should be fluffiness.libraries.yml).

So if your theme is named MyThemeName, the libraries file should be named MyThemeName.libraries.yml, not libfile.libraries.yml