old Fusion is an application server and software development framework used for the development of computer software in general, and dynamic web sites in particular. In this regard, ColdFusion is a similar product to Microsoft ASP.NET, JavaServer Pages or PHP.
The primary distinguishing feature of ColdFusion is its associated scripting language, ColdFusion Markup Language (CFML), which compares to JSP, ASP.NET, or PHP and resembles HTML in syntax. "ColdFusion" is often used synonymously with "CFML", but it should be noted that there are additional CFML application servers besides ColdFusion, and that ColdFusion supports programming languages other than CFML, such as server-side Actionscript and embedded scripts that can be written in a JavaScript-like language, known as CFScript.
Originally a product of Allaire, and released in July 1995, ColdFusion was originally developed by brothers JJ and Jeremy Allaire. In 2001 Allaire was acquired by Macromedia, which was in turn acquired by Adobe Systems in 2005.
ColdFusion is most often used for data-driven web sites or intranets, but can also be used to generate remote services such as SOAP web services or Flash remoting. It is especially well-suited as the server-side technology to the client-side Flex.
ColdFusion can also handle asynchronous events such as SMS and instant messaging via its gateway interface, available in ColdFusion MX 7 Enterprise Edition.
ColdFusion provides a number of additional features out of the box. Among them:
ColdFusion was originally not an object-oriented programming language, and even today lacks some OO features. ColdFusion falls into the category of OO languages that do not support multiple inheritance (along with Java, Smalltalk etc.). With the MX release (6+), ColdFusion introduced the component language construct which resembles classes in OO languages. Each component may contain any number of properties and methods. One component may also extend another (Inheritance). Components only support single inheritance. With the release of ColdFusion 8, Java-style interfaces are supported. ColdFusion components use the file extension cfc to differentiate them from ColdFusion templates (.cfm).
ColdFusion Server includes a subset of its Macromedia Flex 1.5 technology. Its stated purpose is to allow for rich forms in HTML pages using CFML to generate Flash movies. These Flash forms can be used to implement rich internet applications, but with limited efficacy due to the ActionScript restrictions in place on Flash forms by Macromedia.
Flash forms also provide additional widgets for data input, such as date pickers and data grids.An example:
<cfform format="flash" method="post" width="400" height="400">ColdFusion also includes some XForms capability, and the ability to "skin" forms using XSLT.
Component methods may be made available as web services with no additional coding and configuration. All that is required is for a method's access to be declared 'remote'. ColdFusion automatically generates a WSDL at the URL for the component thusly: http://path/to/components/Component.cfc?wsdl. Aside from SOAP, the services are offered in Flash Remoting binary format.
Methods which are declared remote may also be invoked via an HTTP GET or POST request. Consider the GET request as shown.
This will invoke the component's search function, passing "your query" and "strict" as arguments.
This type of invocation is well-suited for AJAX-enabled applications. ColdFusion 8 introduced the ability to serialize ColdFusion data structures to JSON for consumption on the client.
The ColdFusion server will automatically generate documentation for a component if you navigate to its URL and insert the appropriate code within the component's declarations. This is an application of component introspection, available to developers of ColdFusion components. Access to a component's documentation requires a password. A developer can view the documentation for all components known to the ColdFusion server by navigating to the ColdFusion URL. This interface resembles the Javadoc HTML documentation for Java classes.
ColdFusion provides several ways to implement custom tags, i.e. those not included in the core ColdFusion language. The traditional and most common way is using CFML. A standard CFML page can be interpreted as a tag, with the tag name corresponding to the file name prefixed with "cf_". For example, the file IMAP.cfm can be used as the tag "cf_imap". Attributes used within the tag are available in the ATTRIBUTES scope of the tag implementation page. CFML pages are accessible in the same directory as the calling page, via a special directory in the ColdFusion web application, or via a CFIMPORT tag in the calling page. The latter method does not necessarily require the "cf_" prefix for the tag name.
A second way is the development of CFX tags using Java or C++. CFX tags are prefixed with "cfx_", for example "cfx_imap". Tags are added to the ColdFusion runtime environment using the ColdFusion administrator, where JAR or DLL files are registered as custom tags.
Finally, ColdFusion supports JSP tag libraries from the JSP 2.0 language specification. JSP tags are included in CFML pages using the CFIMPORT tag.
ColdFusion originated as proprietary technology based on Web technology industry standards. However, it is becoming a less closed technology through the availability of competing products. Products include Railo, BlueDragon, IgniteFusion, SmithProject and Coral Web Builder.
The argument can be made that ColdFusion is even less platform-bound than raw J2EE or .NET, simply because ColdFusion will run on top of a .NET app server (New Atlanta), or on top of any servlet container or J2EE application server (JRun, WebSphere, JBoss, Geronimo, Tomcat, Resin, Jetty, etc.). In theory, a ColdFusion application could be moved unchanged from a J2EE application server to a .NET application server
Currently, alternative server platforms generally support ColdFusion MX 6.1 functionality, with minor changes or feature enhancements.
The acronym for the ColdFusion Markup Language is CFML. When ColdFusion templates are saved to disk, they are traditionally given the extension .cfm or .cfml. The .cfc extension is used for ColdFusion Components. The original extension was DBM or DBML, which stood for Database Markup Language. When talking about ColdFusion, most users use the acronym CF and this is used for numerous ColdFusion resources such as user groups (CFUGs) and sites.CFMX is the common abbreviation for ColdFusion versions 6 and 7 (aka ColdFusion MX).
IT commentators have offered various critiques of ColdFusion, discussing both the potential advantages and disadvantages of this technology relative to other alternatives.
The first version of ColdFusion (then called Cold Fusion) was released on July 10, 1995. This first version was written almost entirely by one person, JJ Allaire. Primitive by modern standards, early versions of ColdFusion did little more than database access.
All versions of ColdFusion prior to 6.0 were written using Microsoft Visual C++. This meant that ColdFusion was largely limited to running on Microsoft Windows, although Allaire did successfully port ColdFusion to Sun Solaris starting with version 3.1.
Prior to 2000, Allaire began a project codenamed "Neo", which would rewrite the basis of ColdFusion using Java, which would allow for greater portability among different platforms.
On January 16, 2001, Allaire announced that it would be merging with Macromedia. Shortly after the merger, Macromedia continued with the incremental release of ColdFusion 5.00 and in June 2002, Macromedia released Macromedia ColdFusion MX (6.0), extending the naming convention of Macromedia's line of products. ColdFusion MX was completely rebuilt from the ground up and was based on the Java 2 Enterprise Edition (J2EE) platform. ColdFusion MX was also designed to integrate well with Macromedia Flash using Flash Remoting.
Starting from the MX (6.0) release, ColdFusion is compiled to bytecode, like JSP and ASP.NET. The compiled .class files are readily accessible, and are cached until their source changes, like JSPs.
With the release of ColdFusion MX, the CFML language was also extended to support basic OOP.
With the release of ColdFusion 7.0, the naming convention was amended, rendering the product name "Macromedia ColdFusion MX 7". CFMX 7 added Flash-based, and XForms-based, web forms and a report builder that output in Adobe PDF as well as FlashPaper, RTF and Excel. The Adobe PDF output is also available as a wrapper to any HTML page, converting that page to a quality printable document. The enterprise edition also added Gateways. These provide interaction with non-HTTP request services such as IM Services, SMS, Directory Watchers, and an asynchronous execution. XML support was boosted in this version to include native schema checking.
ColdFusion MX 7.0.2, codenamed "Mystic" includes advanced features for working with Adobe Flex 2.
On July 30, 2007, Adobe Systems released ColdFusion 8, dropping "MX" from its name. During beta testing the codename used was "Scorpio". More than 14,000 developers worldwide were active in the beta process - many more testers than the 5,000 Adobe Systems originally expected. The ColdFusion development team consisted of developers based in Newton/Boston, Massachusetts and Bangalore, India.
Some of the new features are the CFPDFFORM tag, which enables integration with Adobe Acrobat forms, some image manipulation functions, Microsoft .Net integration, and the CFPRESENTATION tag, which allows the creation of dynamic presentations using Adobe Acrobat Connect, the Web-based collaboration solution formerly known as Macromedia Breeze. In addition, the ColdFusion Administrator for the Enterprise version ships with built-in server monitoring. ColdFusion 8 is available on several operating systems including Linux, Mac OS X and Windows Server 2003. Other additions to ColdFusion 8 are built-in AJAX widgets, file archive manipulation (CFZIP), Microsoft Exchange server integration (CFEXCHANGE), image manipulation including automatic captcha generation (CFIMAGE), multi-threading, per-application settings, Atom and RSS feeds, reporting enhancements, stronger encryption libraries, array and structure improvements, improved database interaction, extensive performance improvements, PDF manipulation and merging capabilities (CFPDF), interactive debugging, embedded database support with Apache Derby, and a more ECMAScript compliant CFSCRIPT.
For development of ColdFusion applications, several tools are available: Adobe Dreamweaver CS3, Macromedia HomeSite, CFEclipse, Eclipse and others. "Tag updates" are available for these applications to update their support for the new ColdFusion 8 features.
The standard ColdFusion installation allows the deployment of ColdFusion as a WAR file or EAR file for deployment to standalone application servers, such as Macromedia JRun, and IBM WebSphere. ColdFusion can also be deployed to servlet containers such as Apache Tomcat and Mortbay Jetty, but because these platforms do not officially support ColdFusion, they leave many of its features inaccessible.
Because ColdFusion is a Java EE application, ColdFusion code can be mixed with Java classes to create a variety of applications and utilize existing Java libraries.ColdFusion has access to all underlying Java classes, supports JSP custom tag libraries, and can access JSP functions after retrieving the JSP page context (GetPageContext()).Prior to ColdFusion 7.0.1, ColdFusion components could only be used by Java or .NET by declaring them as web services. However, beginning in ColdFusion MX 7.0.1, ColdFusion components can now be utilized directly within Java classes using the CFCProxy class.
Recently, there has been much interest in Java development using alternate languages such as Jython, Groovy and JRuby. ColdFusion was one of the first scripting platforms to allow this style of Java development. There are, however, some limitations to ColdFusion's ability to offer Java scripting:
ColdFusion 8 natively supports .NET within the CFML syntax. ColdFusion developers can simply call any .NET assembly without needing to recompile or alter the assemblies in any way. Data types are automatically translated between ColdFusion and .NET (example: .NET DataTable ? ColdFusion Query).
A unique feature for a J2EE vendor, ColdFusion 8 offers the ability to access .NET assemblies remotely through proxy (without the use of .NET Remoting). This allows ColdFusion users to leverage .NET without having to be installed on a Windows operating system.
The move to include .NET support in addition to the existing support for Java, CORBA and COM is a continuation of Adobe ColdFusion's agnostic approach to the technology stack. ColdFusion can not only bring together disparate technologies within the enterprise, but can make those technologies available to a number of clients beyond the web browser including, but not limited to, the Flash Player, Adobe Integrated Runtime (AIR), Mobile devices (SMS), Acrobat Reader (PDF) and IM gateways.
Adobe® ColdFusion® is a JavaT application, so ColdFusion applications run on leading J2EE application servers as compiled Java bytecode. This Java DNA makes it easy for you to natively integrate existing Java assets/objects into your ColdFusion applications. But what if you're developing with Microsoft .NET? In previous versions of ColdFusion, there was no native way to integrate those assets into a ColdFusion application. You could use web services to integrate ColdFusion and .NET, but that technique often suffered from poor performance or compatibility problems. ColdFusion 8 software solves this problem by introducing native .NET integration that lets you access Microsoft .NET assembly classes as CFML objects. With ColdFusion 8, now you can leverage .NET objects as easily as Java assets.
The .NET integration capabilities of ColdFusion 8 do not rely on .NET remoting or web services, so no changes to existing .NET assets are required. The .NET classes that your application uses do not have to be local, so your ColdFusion application can access .NET components that are on remote systems, even systems that are outside your firewall. Also, the ColdFusion system does not require .NET runtime software installed to use remote .NET components, so ColdFusion 8 running on a UNIX® , Linux® , SolarisT, or Mac OS X system can access and use .NET assemblies elsewhere on the network. ColdFusion 8 even converts data types automatically, so you don't have to take any special steps to ensure correct conversion among ColdFusion, Java, and .NET data types.