This is the most common question I received after my seminar. The first and most important point about XML is that it's not a language itself. It's a structure that intend to describe data and to be more exact to describe volcabulary. It consists of tags which are enclosed by a pair of angle brackets. The choice of tag names and structures is flexible. Example "<name>" is a tag.
- XML is not a language, its rules are used to construct other languages. HTML is a web page mark up language based on XML.
- XML used tags to mark-up content
- XML is based on SGML.
Now what is SGML? Before XML there was a standard created for mark-up language called Standard Generalized Markup Language (SGML). It is so comphrensive that it is very difficult to use so XML was created to address specific needs.
Monday, October 15, 2007
Monday, January 8, 2007
What is Web 2.0?
Initially I was confused too. I thought that Web is implemented using many standards and technologies and each one has its own version. I decided to do some research...
I come a cross an interesting article that provide my initial insight into this matter.(Follow this link: http://www.oreillynet.com/pub/a/oreilly/tim/news/2005/09/30/what-is-web-20.html)
In the nutshell, Web 2.0 is about a new way of using Web. So it is a concept of Web applications where users are now able to contribute to the contents of the website. Should I still call it portal? Perhaps not because portal is about a central point, from there you can get to the place that you want.
Blog is one application of Web 2.0. Everyone is offered a space on the web site, example www.blogger.com, to put up the contents for any one to see or comment. The contents are open to the public or for invited people only. It is about harnessing collective intelligence as quoted in the article by O'Reilly. Never before can information and views be made available so easily and free.
Wikipedia is another example. Wikipedia, an online encyclopedia, is based on the unlikely notion that an entry can be added by any web user, and edited by any other, is a radical experiment in trust.
There is a downside to this, how about the integrity of the information. Who is responsible for the accuracy of the information?
I come a cross an interesting article that provide my initial insight into this matter.(Follow this link: http://www.oreillynet.com/pub/a/oreilly/tim/news/2005/09/30/what-is-web-20.html)
In the nutshell, Web 2.0 is about a new way of using Web. So it is a concept of Web applications where users are now able to contribute to the contents of the website. Should I still call it portal? Perhaps not because portal is about a central point, from there you can get to the place that you want.
Blog is one application of Web 2.0. Everyone is offered a space on the web site, example www.blogger.com, to put up the contents for any one to see or comment. The contents are open to the public or for invited people only. It is about harnessing collective intelligence as quoted in the article by O'Reilly. Never before can information and views be made available so easily and free.
Wikipedia is another example. Wikipedia, an online encyclopedia, is based on the unlikely notion that an entry can be added by any web user, and edited by any other, is a radical experiment in trust.
There is a downside to this, how about the integrity of the information. Who is responsible for the accuracy of the information?
Sunday, January 7, 2007
Is Ajax and Web Services the same thing?
First I will explain what is AJAX. AJAX stands for Asynchronous Javascript and XML. It is a technique used to update a certain section of a web page without refreshing or reloading the whole page. Why we need to do that? For example, you have a web page which has a news column which display a few lines of news snippets. A “more” button is provided to fetch more information from the server. Without using AJAX, server will response with the whole page of information including those that are not change. The browser will have to reconstruct the whole page again; including the background images, menu, icons etc. This method takes longer time than just updating the section of the page that change, AJAX is used here. You can say that the server is providing a service (news feeding service) and since it is on the web then it is a web service. In strict technical term it is not. Why not?
Web Services strictly speaking is a term used to describe a set of standards that enable one computer to access a set of services or objects on another computers using Internet based network standards. One of the standards is the Object Access Protocol, refer to as SOAP. This standard is used to enable the requesting computer to set up a message which consists of methods and attributes. This is refer to as API (Application Programming Interface). This API can be decribed using a language syntax standard called Web Services Description Language (WSDL). And this information plus other information about the service can be publish to a depository using another standard call UDDI (Universal Discription, Discovery and Integration).
Web Services can be used for Enterprise Application Integration (EAI) or over open Internet environment. It is not restricted on a web application server. Unlike AJAX, Web Services can be used at the server back-end application to access to services provided by other servers in a loosely coupled manner. On the other hand, AJAX focus on the browser and server communications only.
In summary they are not the same.
Andy Tan
Web Services strictly speaking is a term used to describe a set of standards that enable one computer to access a set of services or objects on another computers using Internet based network standards. One of the standards is the Object Access Protocol, refer to as SOAP. This standard is used to enable the requesting computer to set up a message which consists of methods and attributes. This is refer to as API (Application Programming Interface). This API can be decribed using a language syntax standard called Web Services Description Language (WSDL). And this information plus other information about the service can be publish to a depository using another standard call UDDI (Universal Discription, Discovery and Integration).
Web Services can be used for Enterprise Application Integration (EAI) or over open Internet environment. It is not restricted on a web application server. Unlike AJAX, Web Services can be used at the server back-end application to access to services provided by other servers in a loosely coupled manner. On the other hand, AJAX focus on the browser and server communications only.
In summary they are not the same.
Andy Tan
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