Book Image

Mastering Bootstrap 4 - Second Edition

By : Benjamin Jakobus
Book Image

Mastering Bootstrap 4 - Second Edition

By: Benjamin Jakobus

Overview of this book

Bootstrap 4 is a free CSS and JavaScript framework that allows developers to rapidly build responsive web interfaces. This book will help you use and adapt Bootstrap to produce enticing websites that fit your needs. You will build a customized Bootstrap website from scratch, using various approaches to customize the framework with increasing levels of skill. You will get to grips with Bootstrap's key features and quickly discover various ways in which Bootstrap can help you develop web interfaces. Then take a walk through the fundamental features, such as its grid system, global styles, helper classes, and responsive utilities. When you have mastered these, you will discover how to structure page layouts, utilize Bootstrap's various navigation components, use forms, and style different types of content. Among other things, you will also tour the anatomy of a Bootstrap plugin, create your own custom components, and extend Bootstrap using jQuery. You will also understand what utility classes Bootstrap 4 has to offer, and how you can use them effectively to speed up the development of your website. Finally, you will discover how to optimize your website and integrate it with third-party frameworks. By the end of this book, you will have a thorough knowledge of the framework's ins and outs, and will be able to build highly customizable and optimized web interfaces.
Table of Contents (18 chapters)
Title Page
Copyright and Credits
Packt Upsell
Contributors
Preface
Index

Browser detection


Do you remember, the hypothetical example from Chapter 4,On Navigation, Footers, Alerts, and Content, where MyPhoto only supports browsers above certain versions? We added a Bootstrap alert to our page, which notified visitors that their browser is not supported. Up until now, however, we had no way to actually identify which browser or browser version a MyPhoto visitor was using. Lacking any logic to hide or display the alert, the alert was visible regardless of whether or not the user's browser was actually supported by our website. Now the time has come for us to implement this missing logic.

Web browsers identify themselves by specifying their name and version information using a special field called User-Agent, which is part of the HTTP Request Header (refer to figure 5.1). JavaScript allows users to access this field using the window.navigator property. This property contains the exact same string that is present in the User-Agent field of the HTTP Request Header....