How to add global style to angular 6/7 library

Question

I was trying to add global styles in the same way like in angular app, but it totally does not work.

My libraries' name is example-lib, so I added styles.css to /projects/example-lib/. I added styles in main angular.json file:

...
"example-lib": {
  "root": "projects/example-lib",
  "sourceRoot": "projects/example-lib/src",
  "projectType": "library",
  "prefix": "ngx",
  "architect": {
    "build": {
      "builder": "@angular-devkit/build-ng-packagr:build",
      "options": {
        "tsConfig": "projects/example-lib/tsconfig.lib.json",
        "project": "projects/example-lib/ng-package.json",
        "styles": [
          "projects/example-lib/styles.css" <!-- HERE 
        ],
      },
...

but when I tried build library using command:

ng build example-lib

I got error:

Schema validation failed with the following errors:
  Data path "" should NOT have additional properties(styles)

I guess that is the other way to add global styles in separate library. Anyone can help me?

Answer 1

I have a workaround for this. Just create the root component of your library without view encapsulation and all its styles will be then global.

my-library.component.ts

import { Component, OnInit, ViewEncapsulation } from '@angular/core';

@Component({
  selector: 'lib-my-library',
  templateUrl: './my-library.component.html',
  styleUrls: ['./my-library.component.scss'],
  encapsulation: ViewEncapsulation.None
})
export class MyLibraryComponent implements OnInit {

  constructor() { }

  ngOnInit() {
  }

}

my-library.component.html

<!-- html content -->

my-library.component.scss

@import './styles/core.scss';

Now your my-library.component.scss and core.scss are global

styles/core.scss

body {
    background: #333;
}

core.scss is optional, I just like to keep the root files clean.

---

Update: In case you want your mixins and variables too, then follow this answer.

Answer 2

From Compiling css in new Angular 6 libraries:

1. install some devDependencies in our library in order to bundle the css:

   • ng-packagr
   • scss-bundle
   • ts-node

2. Create a css-bundle.ts

3. Add _theme.scss inside the /src directory of the library that actually contains and imports all the css that we want to bundle.

4. Add postbuild npm script to run the css-bundle.ts:

5. Include it in the styles tag in your Application in the angular.json

Answer 3

From this issue solution

Install cpx and scss-bundle as Dev dependencies to your package.json. Then add the following entries in your package.json "scripts" property:

"scripts": {
  ...
  "build-mylib": "ng build mylib && npm run build-mylib-styles && npm run cp-mylib-assets",
  "build-mylib-styles": "cpx \"./projects/mylib/src/lib/style/**/*\" \"./dist/mylib/style\" && scss-bundle -e ./projects/mylib/src/lib/style/_style.scss -d ./dist/mylib/style/_styles.scss",
  "cp-mylib-assets": "cpx \"./src/assets/**/*\" \"./dist/mylib/assets\"",
  ...
}

Replace "mylib" with your real library name and then just run in your terminal build-mylib. That would complile your scss aseets to your dist folder.

Yo use this global styles in your actual Angular project just import them in your angular.json file within your project settings:

"styles": [
  "src/styles.scss",
  "dist/my-shiny-library/_theme.scss"
],

(use dist if your project is in the same workspace, or node_moduled if its an imported library)