Web basics

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Book description

This book introduces web basics, covering the following contexts/topics: HTTP, Front-ends, XML and JSON. It is meant as a very gentle introduction to web technology for any one who's interested in how the web and its applications works. You can read this book as a stand-alone book presenting the basic concepts and technologies, or as a warm-up for more advanced books like our Java_Web_programming book.

As this book is a work-in-progress, it will (like all our books) be subject to constant additions and modifications. Well, that's kind of why we, the authors, choose a Wiki as the basis for all our books.

Book chapters

Each chapter is described shortly below, divided into the basic contexts of this book, HTTP, Web-front-ends, XML and JSON.

The full list of chapters is:

More topics and chapters might be added in the (near or distant) future.

An example web application (which also contains a challenge) can be found at our page Id-iot_-_Informatics_Driven_Internet_Of_Things.

Basic concepts explained

HTTP

This is the basis of all communication between a client and a web server. It's a high-level (application level) protocol specifying what request a web client (like a browser for instance) can send to a web server, and what a response from a web server can look like.

Web front-ends (TODO)

If you are using a browser as the client to consume web stuff from web servers (e.g. surfing or downloading files), we need to know what a web page looks like, in its raw form (the way the code for at web page was typed in by a web designer). HTML is the mark-up language used for web pages. Web pages can, however, look very dull in their plainest form. So we'll also look very basically at styling web pages using style sheets in CSS.

In order to do some logic in a web page, we'll also introduce JavaScript, a programming language which can be embedded in (or combined with) web pages, in order to have some code with logic or interaction elements, in a web page being viewed in a browser.

Finally, we will show an application of JavaScript called Ajax (or AJAX), which actually allows a web page loaded in a browser to change dynamically (after it's been downloaded by the browser).

XML

AJAX can use an XML-file on a web server as the source for data when updating a web page the user is viewing. So, we'll introduce here the basics of the XML markup language. XML can be used for a million other tasks, so learning about the XML format is a very useful skill.

JSON

A close friend of AJAX is AJAJ. It works pretty much like AJAX but uses JSON as the data format instead of XML. As with XML, JSON can be used for many other purposes than AJAJ and is today probably the most common format for transmitting data over the web. So you'll have great use a of basic understanding of the JSON format.