Server-side web programming

Principle

When inserting the server side script in a page, when the visitor requests the page, the server will first read it, it will interpret the server code, and encapsulate the result in the HTML page. The latter will be sent to the visitor without any trace of the server code. The visitor thus receives a pure html page (possibly even the client code).

In this process, we gain enormously in secure coding. We also have a large number of potential interactions with other systems or applications such as databases.

“Server side” page files usually have an extension other than htm or html. The extension will depend on the technology used.

Different technologies

Microsoft technologies

ASP (Active Server Pages): developed by Microsoft in 1996 in order to create dynamic pages. ASP allows you to add code in the HTML page that will be performed by the server. ASP‘s ADO part (ActiveX Data Object) is used to connect to a database.

• Languages used: VBScript (default language) or JScript.
• Portability: The technology is implemented on web servers (IIS and PWS).
• Setup: Using script language therefore relatively easy access (but complex quickly).
• Performance: Good performance especially when using compiled code (dll).
• Use: A dynamic website can be created in ASP.

ASP.NET: Technology developed by Microsoft based on the Framework.Net. The change is significant compared to ASP and the possibilities become endless. ASP.NET has a big advantage over other technologies, to separate the content of the web page, its layout and programming of dynamic aspects (work in Code Behind).

• Languages used: C#, VB.Net, JavaScript.Net … and many other languages that share the Common Runtime Language of Framework.Net.
• Portability: The technology is implemented on web servers (IIS 2003).
• Setup: Using programming language and therefore requires a good grounding in programming but the language is irrelevant (multiple languages). With version 2 (ASP.NET 2.0) and a development tool like Visual Studio, application development can already get very far without programming: many controls are managed by their properties.
• Performance: Excellent performance because all the code is compiled (or precompiled or compiled on the fly).
• Use: All type of web application can be created with ASP.NET.

PHP

PHP (Hypertext Preprocessor) is aserver side interpreted scripting language. The PHP code is read by the server and interpreted to produce a HTML page (or other file types such as pictures or PDF documents) each time the page is requested. This language was originally created as part of Open Source software. Many developers have profited from the Open Source to develop many ready to use and customizable modules at will.

• Portability: The PHP server modules are implemented on Apache servers and Unix but PHP can be implemented on other platforms via CGI. PHP typically works with a MySQL database.
• Setup: PHP is a scripting language, and therefore relatively easy to learn. The syntax is simplified, but from a base of C.
• Performance: Very good performance. The only limit would be the rapid development of modules and therefore sometimes the need to “refresh” the programming.
• Use: All type of web application can be created with PHP.

Java technologies

JSP (Java Server Pages) developed by Sun Microsystems in order to create dynamic pages with Java technology. JSP can add Java code in the HTML page that will be performed by the server. There are three sets of instructions JSP:

• Programming instructions for inserting pieces of Java code directly into the web page, and provide access to much of the programming library of the standard version of Java (JavaBeans components, accessing databases via JDBC etc. )
• Guidelines that specify certain properties of the page, including the contents of other files and the use of other classes and custom tag libraries.
• Actions allow essentially to use existing JavaBeans.
• Portability: Very high portability with Java: Apache but also IIS, etc.
• Setup: Using Java as a programming language.
• Performance: Highly variable depending on the implementation used.
• Use: All types of features.

Servlets: The name comes from the possible analogy with applets. There are therefore programs created in Java and running on the web server. Running the program generates Web pages returned to the client.

• Languages used: Java.
• Portability: Very high portability with Java: Apache but also IIS, etc.
• Setup: Using Java as a programming language.
• Performance: Highly variable depending on the implementation used.
• Use: All types of features.

ColdFusion

ColdFusion is a technology to create dynamic pages developed, by Macromedia. The application pages are web pages containing programming instructions written using a proprietary language, CFML (ColdFusion Markup Language). CFML is a simple language based on tags whose syntax is similar to that of HTML but interpreted by the server.

Ajax (Asynchronous JavaScript And XML)

Ajax is a technology with its advantages and disadvantages, which combines several elements:

• XHTML for the structure of the page,
• CSS for formatting the page
• JavaScript and the DOM to the dynamic part,
• XML, XSLT and XMLHttpRequest for data manipulation (or other formats of data files).

Basically, this technology allows an asynchronous HTTP request (in parallel) to the web server (perform an action, update information …). The server returns the requested, it may contain information or code to update the HTML resource.

Translated from Wikipedia