3-tier (XML vs .NET)??

[hertshelp]

Hi all,

I would like to know if and how it is possible to use ONLY XML to create a 3-tier website.

Please could you also let me know if an XML based approach would be better than an ASP.NET approach (for example), with reasons..

Much appreciates guys, thanks!!

[Alsvha]

I am somewhat mystified by your question which is why I respond.

When you talk about 3-tier website and XML, and ONLY XML - do you mean you'll in fact only use XML - or just use XML as a data-tier for storage of information versus databases?

Because ASP.NET is a programming language (using an underlying .NET language, eg: C# or VB.NET, for server side code), and XML is basically just a data format; although XSLT allows for data transformation.

The two are not comparable in the manner you ask your question - hence my curiosity?

[hertshelp]

You're right, the question is wierd. I'm having a hard time getting my head around it..

I did find this which uses Uniface too send XML streams... Also, this paper which suggests using XML RIKA as the middleware.


But you have answered one of my queries already. XML is for something completely different..

So could you possible explain the best (most efficient) 3Tier structure for websites? Explaining the most effective role(s) for XML and its associated technologies (XSLT).. And the most effective partner for it inc. DB's and scripting langs.


I have been approached by an online shopping company who want me to brief them about how to use XML in Three Tier Architecture and the benefits associated with it.



Hope this clarifies just a little bit more... Don't give up on me lol, just trying to get to grips with it.

[Alsvha]

XML is usually used for data-storage or data-exchange and has little else to do with "architecture" in my experience/view.
Meaning you store the information - like you would in a database or other files (comma separated files).
Because of the way it is defined, it is often used for importing/exporting data to an application/service.

You still need to do something with the data depending on what you want to actually do with it, and that is where data layers and other tiers come into play.
If you want to store information, you need something to get the information as input (user, files whatnot), and save it in a manner of your choosing (regardless of whether you use databases or files to store it in).


XSLT (data transformation) is used for transforming the XML data from one source into target XML or HTML. This makes it easier to handle import and export of data for example.

As for what is most "effective" that is so dependant on what you are attempting to achieve that it is impossible to give you advice about, but something you must analyse your way to, based on your specifications and requirements for the project. Generally however, IMO, XML is best used for data-transfer (import/export) and only lightweight storage of information.


This is however a huge topic, and I'm by far no expert myself in this area, so I would suggest that you try to find some (online or offline) references to support your analysing of the situation you have specifically to you.

[stlowe]

Alsvha is right, this is a huge topic.
I'd consider refining your query. For example, you ask for the "best (most efficient)" 3-tier architecture. But what does that mean? Efficient could mean:
1. Least latency between browser request and server response.
2. Most responsive user interaction.
3. Quickest, cleanest, and least bug-prone development effort.
4. Least content management effort.

Returning to XML vs .NET.
For item #1: this kind of performance generally turns out to be as much implenetation than architecture dependent.
For item #2 above, XML is a component of AJAX, which is intended to reduce the need for POSTBACKS as part of event handling...and ASP.NET supports AJAX, so you can use XML with .NET.
For item #3, I vote for ASP.Net. It sure beats unmanaged ISAPI filters for ease of development.
For item #4, XML is often used to move content between a database and an HTML stream (XSLT, as mentioned in a previous post, is one way of transforming XML that was generated from a SQL Server query into HTML).
You can do this with ASP.Net.

Stephen Lowe
Disclaimer: though I work for Microsoft as an Architect Evangelist, my opinions (and occasional errors) are my own