Web Services and APIs

Like this on Facebook. Read my Twitter feed. Have a look at the Google map below to see where we are. These are the kind of statements that web users are getting used to in a Web 2.0 environment. Usually, however, not a lot of thought goes into how these buttons and feeds are actually integrated into web pages. However, this is what we discussed this Monday in our DITA lecture.

APIs provide an interface, without any requirement for technical understanding of what goes on in the background, thereby reducing the need for technical understanding. The ideal is that people will be able to create APIs with no programming background whatsoever. Our lecturer described APIs as an underlying pillar of Web 2.0. APIs (generally it is agreed that this stands for Abstract or Application Programming Interface) are programming tools. PC Mag (no date) describes what APIs are and how they work:

A language and message format used by an application program to communicate with the operating system or some other control program such as a database management system (DBMS) or communications protocol. APIs are implemented by writing function calls in the program, which provide the linkage to the required subroutine for execution. 


A web service is a type of API. O'Reilly (2009) states that 'a web service is any piece of software that makes itself available over the Internet and uses a standardized XML messaging system'. A web service, as the name implies, is a service (software) which is available over the Internet. Web services use the same technology as web pages (the client-server relationship), and it even looks a bit like HTML because XML uses tags. However, web services are content only - unlike web pages there is no structure to an XML document. Additionally, where web pages are designed to be read by humans, web services are designed to be read by machines.

While XML means eXtensible Markup Language, it is not actually a language. Instead, it provides conventions for creating your own language with tags; it is sometimes described as a meta language. As it is not strictly a language, there is no international standard; to quote Pirates of the Caribbean, 'the code is more what you'd call "guidelines" than actual rules.'

An example of APIs

Let's say I don't understand the way that Facebook works, but I want to let people 'like' my page. The nice people at Facebook have put the code on the web so that you can do just that. I have done so, on my 'mash up' web page here. It is unnecessary to understand exactly what the code means, because it works. Although, if you are interested the coding you need is:

<div id="fb-root"></div>
<script>(function(d, s, id) {
  var js, fjs = d.getElementsByTagName(s)[0];
  if (d.getElementById(id)) {return;}
  js = d.createElement(s); js.id = id;
  js.src = "//connect.facebook.net/en_GB/all.js#xfbml=1";
  fjs.parentNode.insertBefore(js, fjs);
}(document, 'script', 'facebook-jssdk'));</script>

Then where on your web page you want the code to appear you need to add:

<div class="fb-like" data-href="http://www.student.city.ac.uk/~abkb846/public_html/MashUp.html" data-send="true" data-width="450" data-show-faces="true"></div>

You can put this on any web page, the only bit you need to change is the URL, which I have made bold above. The script above is a bit confusing for humans to read, but easy for machines to understand. It is 'asking' Facebook to run its 'Like' process on the web page, without the owner of the web page needing to understand how Facebook does this in the first place. The Facebook API is the interface which allows applications to communicate with each other (usually without the awareness of the user at all).

Conclusion


To sum up, the use of APIs could potentially open up programming to users, as the need for coding knowledge is reduced. APIs are incredibly useful for social media as they are great for communication. They open up communication between different programs and allow people to improve functionality of web sites. 

O'Reilly Media (2009) Top Ten FAQs for Web Services. Available at http://www.oreillynet.com/lpt/a/webservices/2002/02/12/webservicefaqs.html [Accessed 7 November 2011]
PC Mag (no date) Definition of API. Available at http://www.pcmag.com/encyclopedia_term/0,2542,t=application+programming+interface&i=37856,00.asp#fbid=9qFJ8KQn0H3 [Accessed 7 November 2011]