Green - ReactJS: Web App Development: Learn one of the most popular Javascript libraries

You will also be guided on how to write your first React program. Sometimes, your program might involve a combination of a HTML, a CSS, and a React code. After reading this book, you will know how to write these separately, and then run them so as to achieve your result. Components, which are a common feature in React, are deeply explored in this book. The book discusses how to create components with no details left out. You will get to know how to add data to the components that you create in React, as well as creating subcomponents in React.

The various ways in which one can add state to the components that have been created in React is also explored. This nook will guide you on how to choose the best method for doing this in React. Events, in which you need your component to do something after selection,are discussed in detail. After reading this book, you will get to know how to create a comment box in React. The user interface is explored in detail including breaking it into a number of components. Animations are also discussed.

The following topics are explored:

• Definition
• Creating Components in React
• Comment Box in React
• Breaking the User Interface into an Hierarchy of Components
• Creating Forms in React
• Animations in React
• Two-way Binding Helpers in React
• Transferring Props
• React and Browsers

The library is very good in supporting animations. The animation can involve either a single word or image, or multiple images or words. This explains why most websites with an image carousel in which image sliders are created for the web pages of the site are developed using this Javascript library. This also shows how good the library is in enhancing the user interface of web applications. With this library, the user interface can be broken into a number of components.

Chapter 1
Definition

This is a Javascript Library, and it is used for development of user interfaces.

The library is open-source, and most people refer toit as React.js or ReactJS. The library was developed so as to solve the problems that programmers experience when developing applications which are only a single page. It is maintained by Instagram, Facebook, and a group which is made up of developers. With React, one can develop large applications and use data which can change frequently. This can be done in a very simple manner. Note that it can only be used to develop the interface part of your application, since in terms of MVC (mode-view-controller), it only forms the view.

It is possible to integrate this library with other Javascript libraries such as AngularJS. Although it is used for development of the user interface alone, it is possible to use add-ons which react to events together with this library, so as to create amazing web applications. In terms of DOM (Data Object Manipulation), it maintains a DOM which it comes with, meaning that it doesnt rely very much on the DOM of the browser. This means that it is easy to know the parts of the DOM which have changed by comparing it with the one being stored. It can then update the DOM of the browser.

Getting started with React Javascript

You need to first download the library.

This can be downloaded from GitHub. The downloaded file will always be in a zipped format. You have to extract it so that it can become usable. The files in which you write your code should be saved in the same directory where you have extracted the contents of the download. They should also be saved with an .html extension. Let us demonstrate this by writing our first sample code in React: Extract the contents of the file in a certain directory.

Open your text editor of choice, such as notepadornotepad++ if you are using Windows. For Linux and Mac OS X users, use text editors of choice such as VIM in Linux and Emacs in Mac. Just write the following code in the editor: React.render(

Hello, welcome to React!

, document.getElementById('hello') ); Once you have written the code, save the file with an .html extension and in the same directory where you extracted the contents of the downloaded file. Open the file with your browser, and observe the output. The following should be observed: From the figure shown above, it is very clear that the code has produced the words which we specified as the output. It is also possible to write the React code separately.

Write the following src/hello.js code: React.render(

Hello, welcome to React!

, document.getElementById('hello') ); Just save the above file with a .js extension so as to imply that it is a Javascript file. This should then be referenced from the file saved with the ,html extensionas follows: The HTML file should then be updated as follows: You can then run your code, and you will observe the following output: It is very clear that we have achieved the same result, but by different methods.