HOW TO INSTALL BOOTSTRAP 5 IN ANGULAR

There are other packages out there that you can use such as ngx-bootstrap, but this is the vanilla Bootstrap (including JavaScript) method.

There are some slight differences from versions before Angular 6. This post is for 6+ and will show you how to install Bootstrap 4 or 5 in Angular using either CSS or SCSS/SASS .

If you’re using CSS:

1. From the root of your project you need to install Bootstrap 5, and Popper.js which is used for dropdown menu’s and other JavaScript sort of things:

    npm install bootstrap popper.js --S
   

2. Update your angular.json file with the same code snippet below in two places: Underneath "build" and "test":

    "styles": [
      "src/styles.css",
      "./node_modules/bootstrap/dist/css/bootstrap.min.css",
    ],
    "scripts": [
      "./node_modules/popper.js/dist/umd/popper.min.js",
      "./node_modules/bootstrap/dist/js/bootstrap.min.js"
    ]
   
3. Since we updated angular.json you’ll have to restart your server. Once you do that you should be good to go for the CSS version.

If you’re using SCSS or SASS:

1. From the root of your project you need to install Bootstrap 5, and Popper.js which is used for dropdown menu’s and other JavaScript sort of things:

    npm install bootstrap popper.js --S
   

2. Update your angular.json file with the same code snippet below in two places. Underneath "build" and "test":

    "styles": [
      "src/styles/styles.scss",
      "./node_modules/bootstrap/scss/bootstrap.scss"
    ],
    // See blurb about this below, and delete this comment.
    "stylePreprocessorOptions": {
      "includePaths": [
        "src/styles",
        "./node_modules/bootstrap/scss"
      ]
    },
    "scripts": [
      "./node_modules/popper.js/dist/umd/popper.min.js",
      "./node_modules/bootstrap/dist/js/bootstrap.min.js"
    ]
   

       To read more about stylePreprocessorOptions go to   Angular/CLI README .  It’s a quick (3 min) read and definitely a good thing to be aware of if you’re working with SASS, LESS, etc in Angular.
3. Create a styles directory/folder in /src. So it should be src/styles.
4. Now move your styles.scss file into that directory and create your variables, mixins and custom files to that src/styles directory using the following naming convention: _variables.scss, _mixins.scss and _custom.scss.

    src
    ├── app
    │   ├── app-routing.module.ts
    │   ├── app.component.html
    │   ├── app.component.scss
    │   ├── app.component.spec.ts
    │   ├── app.component.ts
    │   ├── app.module.ts
    │   └── users
    ├── assets
    ├── environments
    │   ├── environment.prod.ts
    │   └── environment.ts
    ├── favicon.ico
    ├── index.html
    ├── main.ts
    ├── polyfills.ts
    ├── styles
    │   ├── _custom.scss /* Add files here but they should have the "_" pre-pended like `_custom.scss`, (shown above) other than `styles.scss`.  */
    │   ├── _mixins.scss /* Your editor and the lang strips these but I'm not entire sure why they are needed, but that's what I was taught. */
    │   ├── styles.scss
    │   └── _variables.scss  /* Add files here but they should have the "_" pre-pended like `_custom.scss`, (shown above) other than `styles.scss`.  */
    └── test.ts
   

5. Now open your styles.scss file and import Bootstrap and your custom/mixin/variable files:

    /* Bootstrap */
    @import 'bootstrap';
   
    /* Custom */
    @import 'variables';
    @import 'mixins';
    @import 'custom';
   

6. To use your variables in other components, you’ll have to import them into every
   component-name.component.scss file like so. But because we imported all of Bootstrap’s .scss files into our angular.json file, we can leave off the path which makes things much cleaner:

    /* component-name.component.scss */
    @import 'variables';
   

7. Since we updated angular.json you’ll have to restart your server.