Yes, even the complex enterprise applications bursting with large data tables and charts. Even if it isn’t the best fit, every type of content should be accessible from any kind of device…

Responsive web design (RWD) is an approach to web design which makes web pages render well on a variety of devices and window or screen sizes — Wikipedia

or for the more visual folks…

We have been building responsive web apps since forever so what’s the big deal ?!

Well, after many years of waiting, Bootstrap 4 was finally released in January 2018. Bootstrap was the first widely popular css framework which contained responsive css grid as one if its main features. The new version built upon this successful foundation and brings many improvements which makes working with responsive grids even easier.

# Bootstrap is the OG of the responsive layouts

Angular 6 was released in May 2018. It brought unification of versioning in the Angular ecosystem. This means that all Angular projects are now released together.

Angular CLI 6 changed quite a lot in comparison to previous versions. New angular.json config file has completely different structure than the original angular-cli.json . This has some implications for how we approach Bootstrap / Angular integration in our projects.

There are many approaches to building responsive apps with Angular. Feel free to use one of the many available css frameworks or use Angular semi-official flex-layout library. Personally, I prefer Bootstrap because of simple declarative approach which is decoupled from the application logic. As always, use what is best for your particular use case.

In this post we will integrate Bootstrap 4 in a fresh Angular 6 project generated using Angular CLI. Feel free to check out Angular Ngrx Material Starter if you’re interested in more complete example (GitHub repo).

We’re going to focus on using Bootstrap grid to create responsive layouts in Angular applications, therefore we will be only using bootstrap-grid and bootstrap-reboot packages. We will NOT be using any Bootstrap styling or components like dropdowns or forms…

# Angular 6 ❤️ Bootstrap 4

First, we create new Angular project using Angular CLI’s ng new command…

ng new angular-bootstrap-example --style scss --prefix abe

In the command above, we are setting up support for Sass styles with .scss file extensions and prefix for our components as a initial letter of the project, hence abe.

Next, we have to install Bootstrap using

npm i -S bootstrap

Let’s look into our main styles.scss file located in src folder and add following two lines…

@import '~bootstrap/scss/bootstrap-reboot';
@import '~bootstrap/scss/bootstrap-grid';

That’s all that we need to start using Bootstrap responsive grid in our Angular project!

Another way of doing this would be adding minified Bootstrap distribution straight into angular.json file like in the following heavily simplified example…

{
  "projects": {
    "angular-bootstrap-example": {
      "...": "...",
      "architect": {
        "build": {
          "options": {
            "...": "...",
            "styles": [
              "node_modules/bootstrap/dist/css/bootstrap-reboot.css",
              "node_modules/bootstrap/dist/css/bootstrap-grid.css",
              "src/styles.scss"
            ]
          }
        }
      }
    }
  }
}

We can add Bootstrap css files straight into “styles” property in angular.json (per project)

Importing Bootstrap grid in the main style.scss file has one major advantage over importing it in the angular.json file. It enables us to override any Sass variable used by the Bootstrap styles definitions.

In practice, it can be useful to create styles-variables.scss file next to our styles.scss in the src folder with responsive layout breakpoints (as defined in Bootstrap by default).

$grid-breakpoints: (
  xs: 0,
  sm: 576px,
  md: 768px,
  lg: 992px,
  xl: 1200px
);

Using styles-variables.scss gives us ability to override default Bootstrap grid and implement consistent custom responsive styles in our components

That way we can import it on the first line of our styles.scss to be used with Bootstrap but also in any other component styles file to implement custom responsiveness in a consistent manner.

@import "styles-variables";

@import '~bootstrap/scss/bootstrap-reboot';
@import '~bootstrap/scss/bootstrap-grid';

Import styles-variables.scss in the main styles.scss file to be used with Bootstrap

@import '../styles-variables';

abe-header {
  nav {
    width: 100%;
  }

  @media (min-width: map-get($grid-breakpoints, sm)) {
    nav {
      width: 80%;
    }
  }
}

Import styles-variables.scss in the styles of the custom component (eg header.component.scss) to implement custom responsive styling in consistent maner

PRO TIP: Styles implemented in styles.scss file are applied only after application has already started up. You might want to display loading indicator before that happens to achieve better user experience on slower networks in many emerging markets. In that case you will have to add some inline styles directly into index.html Learn how to implement this by checking one of my previous posts… 🎨 How To Style Angular Application Loading With Angular CLI Like a Boss 😎 *Slow internet is a fact of life in many places around the world. Prompt users to wait instead of leave with nice…*medium.com

# Building responsive layout

Adding Bootstrap reboot and grid enables us to easily build responsive layouts. Let’s see how it works by building a minimal example.

Our layout will have header, content and footer. The content will contain two main sections. We want to display them side by side on the large screens. On the smaller screens, we want them to be displayed as a single column, one under the other.

Please notice that in our example, all parts of the layout will be implemented inside of AppComponent. In the real world application, all the parts would probably be implemented as stand alone components like HeaderComponent, FooterComponent and the content would be probably populated with the help of the Router based on the current url… To see that in action, check out this more complex project…

# Basic responsive grid classes

Let’s start with a quick recapitulation of how to build responsive layouts with Bootstrap. Feel free to skip this section if you have some previous experience with Bootstrap…

Layout is usually wrapped in the element with .container class to make it a bit narrower and centered on the very large screens. You might want to skip .container when building dashboards though. The next wrapper element uses .row class to signify responsive row. Every row has 12 columns by default.

Columns can be specified using .col class which applies to the extra small screens. We can add additional modifier like -sm -md -lg -xl to limit its effect to a particular screen size. Columns take appropriate amount of space based on their count. In practice, we often specify column size explicitly. For example, we can have a row with .col-md-4 and .col-md-8 which adds up to 12 columns. Check out official documentation for more details…

<header></header>

<div class="container content"> <!-- container centers content on large screens -->
  <div class="row">             <!-- responsive row has 12 columns by default -->
    <div class="col-md-6">      <!-- uses 6 columns on medium and larger screens... -->
    </div>
    <div class="col-md-6">      <!-- uses 12 columns on smaller than medium screens -->
    </div>
  </div>
</div>

<footer></footer>

Example implementation of our responsive layout

# Responsive helper classes

Building high-level responsive layout is only half of the story. Often, it is also the content of the particular element which has to be responsive.

Imagine you have a header toolbar with a logo, company name and a navigation menu. On smaller screen, the amount of space becomes very limited so we might want to hide company name and display only the logo.

# ⚠️ Responsive helper classes work differently in Bootstrap 4

Previous versions of Bootstrap used responsive helper classes like .hidden-xs or .visible-sm-inline. This have changed. Current responsive helpers are more in line with css itself by following its display property.

This means that to achieve <div class="hidden-xs"></div> we now have to use <div class="d-none d-sm-block"></div>.

As we can see, helper classes are now “stacked” in a left to right fashion. We start by setting display none for the extra small screens and override it by setting it to block on small screens and larger…

Similarly, if we wanted to hide element only on the largest screens we would use <span class="d-inline d-xl-none"></div>. Notice that we can use any valid css display value as a modifier (eg block, inline-block, flex, …).

It takes some time to get used to the new style but in the end it is much more intuitive

# Using Bootstrap 4 with Angular Material

Building everything from scratch can be fun but often, achieving results **fast **is a much more preferable way of doing business…

We can add Angular Material by running

npm i -S @angular/material @angular/cdk @angular/animations

and importing some of the available modules in our AppModule file. Let’s say we’re interested in a MatToolbarModule and MatCardModule…

import { NgModule } from '@angular/core';
import { BrowserModule } from '@angular/platform-browser';
import { BrowserAnimationsModule } from '@angular/platform-browser/animations';
import { MatToolbarModule } from '@angular/material/toolbar';
import { MatCardModule } from '@angular/material/card';

import { AppComponent } from './app.component';

@NgModule({
  declarations: [
    AppComponent
  ],
  imports: [
    BrowserModule,
    BrowserAnimationsModule, // new modules added here
    MatToolbarModule,
    MatCardModule
  ],
  providers: [],
  bootstrap: [AppComponent]
})
export class AppModule { }

The template then can be adjusted to…

<header>
  <mat-toolbar color="primary">Angular 6 Bootstrap 4 Example</mat-toolbar>
</header>

<section class="container">
  <div class="row">
    <mat-card class="col-md-6">1</mat-card> <!-- we use mat-card instead of div -->
    <mat-card class="col-md-6">2</mat-card>
    <mat-card class="col-md-6 d-block d-lg-none">3</mat-card> <!-- will be hidden on large screens -->
    <mat-card class="col-md-6 d-block d-lg-none">4</mat-card>
  </div>
</section>

<footer></footer>

And a last missing piece is to import one of the pre-build Angular Material themes into styles.scss file and we’re good to go!

@import "styles-variables";

@import '~bootstrap/scss/bootstrap-reboot';
@import '~bootstrap/scss/bootstrap-grid';

@import "~@angular/material/prebuilt-themes/indigo-pink.css";

# 👁️ Check out and play around with this minimalistic working example on ⚡StackBlitz!

# BONUS: Additional resets

Even our minimal inclusion of Bootstrap adds couple of styles that don’t play so nicely with the Angular Material out of the box. Let’s create new styles-reset.scss file with the following content and import it after the original Bootstrap imports in the main styles.scss file.

* {
  &:active,
  :focus {
    outline: none !important;
  }
}

label {
  margin-bottom: 0;
}

Bootstrap also sets link color and uses underline text-decoration on the hovered links. We can remove this styles by adjusting content of the styles-variables.scss file like this..

$grid-breakpoints: (
  xs: 0,
  sm: 576px,
  md: 768px,
  lg: 992px,
  xl: 1200px
);

$link-hover-decoration: none;    // remove underline from button links

$link-color: #3f51b5;            // set link color based on the used material theme
$link-hover-color: currentColor;

Do you want to learn more about how to build your own custom Angular Material themes instead of using the pre-build one? Check out one of my older article… The complete guide to Angular Material Themes Theme your Angular Material apps like a PRO, examples included 😉