ColdFusion - Introduction

What is ColdFusion?

• ColdFusion is a programming language. Like Java, in the sense that it is nothing by itself; it requires a programmer with vision and skill to make anything useful out of it. Like Visual Basic, in the sense that the language is tailored for a specific purpose, but general enough to accomplish most any task easily within that scope. (Visual Basic is designed to make applications for the Windows environment; ColdFusion is designed to make applications for the Web server environment.)

Databases

• ColdFusion was originally designed for allowing database contents to be easily displayed in Web pages for any browser, without plugins, by manipulating the HTML output of a Web browser. Since the browser is fed nothing other than standard HTML, no plugins are needed.

More..!

• ColdFusion also makes gathering, manipulating, and presenting data from other data sources easy, including other Web servers, FTP servers, ASCII data files, POP mail servers--not even COM and CORBA objects are safe :-)

Web application server:

• ColdFusion is an application server that runs on a web server. It runs on Linux, Solaris, Windows servers and even the personal web server on Windows 98. The ColdFusion Web application server works with the HTTP server to process requests for web pages. 
• Whenever a Cold Fusion page is requested, the ColdFusion Application Server executes the script or program the page contains. Unlike JavaScript and Java applets, which run on the client, ColdFusion runs on the Web Server itself. Scripts you write in Cold Fusion will run the same way on every browser.

• ColdFusion server was developed by the Allaire Corporation to be a simple to use yet powerful alternative to Perl and other CGI technologies. 

• ColdFusion server is a Rapid Application Development system for professional developers who want to create dynamic Web applications and interactive Web sites. It provides a fast way to integrate browser, server and database technology into Web applications. 

• Developing applications with Cold Fusion does not require coding in a traditional programming language like Perl, C/C++, Visual Basic, Java. You build applications by combining standard HTML with a straightforward server-side markup language, the Cold Fusion Markup Language (CFML). Cold Fusion is a markup language. 

• It can create and modify variables and has program flow controls. It can perform quite complicated tasks. With over 75 CFML tags and over 250 custom functions any web application can be built. Input for Cold Fusion scripts often comes from a user submitting a form to a Cold Fusion template. 

• Cold Fusion application pages handle everything from capturing data a user enters to presenting output. Cold Fusion scripts can also get their input from URL strings, CGI variables or databases. Pages with the .cfm extension are processed without the need for CGI-style URLs to specify an executable. 

• Output from Cold Fusion scripts is typically sent to a user's web browser, put into a database, written to a file or e-mailed. Cold Fusion was designed to build complex, high traffic web sites. ColdFusion server is designed to run on multi-processor systems and allows you to build a dynamic web site that can be run on a cluster of servers.

• Use ColdFusion server to build and maintain databases, process forms, make parts of your web site secure and gather or publish data. You can use it to build web applications like bulletin boards, pop mail clients, online-calendars and chat rooms. Cold Fusion scripts can be written to track hits, clicks, return visits and other valuable traffic statistics. 

• A Cold Fusion application could consist of many application pages, depending on the complexity of your application. Each page performs specific functions in the application. Basically, any function you find on the Internet today can be built and maintained with ColdFusion server.

Databases:

• ColdFusion makes interacting with your database (Sybase, Oracle, MySQL, SQL or Access) simple. Using standard SQL (Structured Query Language) your web pages and web applications can retrieve, store, format and present information dynamically. If you are known with HTML, CFML (Cold Fusion Markup Language) is just one step further. 

• Reading from and writing to servers is tag based. The <CFFILE> tag takes "arguments" which specify 'action=read/write/copy/delete', 'path=' , and so forth.

• The CF tag <CFFORM> will automatically build all the JavaScript code to verify required fields before the form submits. Cold Fusion also has tags to embed COM and Java applets and servlets.

ColdFusion Components:   

• Cold Fusion applications need the following components.

The ColdFusion Application server: 

• The application server runs as a service under Windows NT. The application server listens for requests from the web server to process Cold Fusion application pages. You can stop or start the service.

The ColdFusion Administrator:

• You use the Administrator to configure various Cold Fusion Application server options, including: Cold Fusion data sources,debugging output, server settings and directory mapping.

ColdFusion Application pages: 

• These are the functional parts of a ColdFusion application, including the user interface pages and forms that handle data input and format data output. ColdFusion makes it simple to pass data to a data source and to receive and format data for display.

ODBC Data Sources: 

• ColdFusion uses ODBC to interact with a database therefore you can use any database that supports ODBC as a data source for your Cold Fusion applications. 

• A ColdFusion data source can be any ODBC-compliant database, as well as an Excel spreadsheet, a text file, an LDAP directory server and others.