I'll touch on some of these features in this article, but beyond the "big picture" features, there are many other topics that may interest CF developers as well.

Changes in Packaging
and Marketing The launch of 4.0 initiated several marketing and packaging changes. Note that the names of all the products have changed subtly, with the application server (sometimes referred to previously as CFAS) now being known simply as ColdFusion Server, and both the ColdFusion and HomeSite names have been compressed into single-word representations. There are new logos for all the products, a revamped Allaire Web site, substantial new marketing efforts and a comprehensive series of Road Shows and Regional programs.

More significant to current clients is a new segregation of the ColdFusion product into Professional and Enterprise editions. Gone is the lower-end "workgroup" edition. The Enterprise edition, as its name implies, embodies those features most suitable to higher-end installations. Specifically, Enterprise includes features such as auto-failover, load balancing, native database drivers, CORBA components and advanced security.

Also changed is the price, befitting a more substantial new development system. It's been raised, though it's still a bargain compared to other similar Web development environments. (Frankly, many people got an awful lot of value out of the previous - and quite inexpensive - application server.) There were substantial discounts and generous upgrade paths offered at its launch, most of which have expired. Contact your Allaire sales rep for further details.

Studio Enhancements
While many CF developers have gotten by with simply coding CFML in text or generic HTML editors, it's time for them to reconsider that approach with the enhancements to ColdFusion Studio. Some of the new features mentioned above are in fact features of Studio, or features that benefit from tight integration of Studio with the CF server. Key among those are the new interactive debugging and team development capabilities and server sandbox security. There are many others as well.

The debugger is a fascinating new tool. Anyone who has developed even a modestly complex CF application will have encountered situations in which it's been hard to tell just what was going on with an errant application - whether that was knowing just what code was being executed or knowing the value of a given variable, etc. The debugger solves both problems by enabling a programmer to set breakpoints (or single-step through code) and by monitoring the value of nearly any portion of the environment, including program variables, session and application variables and recordsets. This can also be valuable when you're reviewing someone else's complex code. The debugger can be a tad unstable at times, seeming to become stuck, but it's easily reset in such a situation by pressing the "end debug session" button and debugging again. The benefits well outweigh any first-release challenges.

The team deployment feature includes new integrated server-side source code control (SCC). Whereas previous releases of ColdFusion came bundled with Starbase versions - a fine LAN-based SCC tool - it became clear that Web-based team development was an entirely new animal that called for a more Web-centric, centralized and server-integrated approach. The new release incorporates server-side SCC via Microsoft Source Safe (not included) installed on the ColdFusion Server. (You can certainly continue to use existing client-side SCC packages.) Secure remote development via HTTP rounds out the package to provide more effective team deployment.

Finally, the Sandbox Security feature is an evolutionary - but substantial - change in that it's now possible to create a greater segregation of working environments among team members on the same server (or, more important, unrelated workers in different applications on the same server).

It might be easy to miss some other new enhancements to Studio because they're really enhancements to HomeSite and may be listed as such only in brochures and other descriptions (Studio is really just HomeSite on steroids, with added features to integrate with ColdFusion). Among the new features of HomeSite that "trickle up" to Studio users are:

The two-way visual programming aspect of Studio/HomeSite is interesting and well suited to quick prototyping and creation of initial layouts, but many CF developers will find the feature less than ideal for designing CFML templates. Design mode, as it's called, doesn't render your templates as they will look when CFML tags are executed, so most of the design benefits are lost. Additionally, code alignment can be unexpectedly modified if edited in design mode. There's a "codesweeper" feature that can be turned on to try to compensate for that, but it may be more trouble than it's worth for CFML templates. Try it for yourself.

A more welcome but perhaps easily missed change in 4.0 is that "projects" are no longer a means to create "virtual" collections of files from various directories. This approach had been problematic, especially in regard to keeping the project synchronized as files were added and removed. In 4.0, a project is simply any chosen directory (with optional subdirectories) that, once defined as a project, can then be quickly selected from the projects tab (eliminating the need to traverse the local or remote resource tabs). More important, projects have attendant features such as source code control and one-step upload capabilities (which include uploading only new or modified files as well as encrypting on upload). Projects can also be defined for remote servers (using RDS or FTP), which open such files to other project features, such as "extended find and replace" and "verify links."

Server Enhancements
Some of the new features in ColdFusion Server have clear benefits that are easily understood by most knowledgeable Web developers: automatic failover, dynamic load balancing, native database drivers, CORBA components, etc. The release notes are clear about these if you're not familiar with them, but others listed at the beginning of this article may still have you wondering:
1. "Integrated authentication" is an Enterprise capability that relieves developers of the burden of developing custom login features; more important, it can integrate with NT domains and LDAP directory servers or custom user databases.
2. The "open state repository" capability allows you to alter the location where the values of client variables (enabled via CFAPPLICATION CLIENTMANAGEMENT="yes") are stored on the server. Previously these were stored in the server's registry, but you may now indicate that they be stored in either a database table on the server or in the client's browser as cookies. This not only relieves the burden on server resources but also may open the door to using client variables in sites that previously restricted their use because of the registry burden, and it's the key to maintaining state in a clustered environment where a user's session may be passed across servers.

3. XML integration is primarily embodied in an interesting new feature known as Web Distributed Data Exchange, or WDDX. Whereas much of the industry seems stuck on the idea of XML as a replacement for HTML, Allaire has realized that XML's key role will be to facilitate the exchange of complex data between servers or to/from more intelligent client-side applications. WDDX is a clever, simple, yet effective new tool for just that purpose. With it, CFML variables, data structures and CFQUERY recordsets can be translated into XML (and vice versa) to be passed to other servers, whether running CF or another server platform, or to a browser. It is powerful indeed. Also, a complete set of JavaScript functions is provided to facilitate the creation and use of these XML data structures in a browser-based application. See documentation on the CFWDDX tag for more info.

Several other new enhancements to the server don't warrant mention in some of the high-level, marketing-oriented literature that lists new features, but sometimes it's the little things that'll solve a key problem. Among these are:

Schulze's article also described the powerful new concept of cached or "persistent" queries.

Issue to Note
Even with all the great new features of 4.0, there are still some issues that should be considered before the upgrade is implemented. First, be aware that (as of this writing) the Enterprise package's failover features don't yet work in an NT environment. This is a known issue and Allaire has pledged to offer a free 4.0.1 maintenance release soon to correct this. Similarly, the advanced security features couldn't be implemented initially in Solaris environments and will be corrected in 4.0.1.

Another new improvement to CF is support for stricter code validation. There are several reasons for Allaire to implement this, but the downside is that existing code may no longer validate in the stricter validation. Fortunately, they've offered two tools to assist programmers with this aspect. A new syntax checker can be used to quickly and easily test existing code without relying on execution errors to identify validation errors. You can choose whether to enforce strict validation on a server by way of a setting in the Administrator that allows you to turn it on or off - with a caveat.

Note: Even if you turn off Strict Validation in the Administrator, several changes in CFML syntax may cause legacy applications to fail if they're not corrected. You can't simply turn on 4.0 and turn off Strict Validation and expect all the applications to run. They likely won't. It's crucial that you run all existing templates through the new syntax checker to identify any such code.

Fortunately, you can easily direct the syntax checker (available on the page at start>programs>coldfusion server>welcome to coldfusion) to check all files in a directory (or those matching a pattern). The checker is installed by default in the server's CFDOCS directory and may also be executed directly, such as with http://yourdomain.com/cfdocs/cfmlsyntaxcheck.cfm. Note: The checker reports only the first error in each template, so you'll want to rerun it after making changes until it reports no more errors in all checked templates.

It's imperative that you make this information clear to all developers on your server prior to implementing 4.0.

There are some other subtle changes in the new release. If you used CFEXIT to terminate a template's execution, you'll find that it doesn't terminate execution if it's executed within a template called by either CFINCLUDE or CFMODULE. The correct tag is CFABORT. (Technically, CFEXIT is for use in custom tags.) This behavior can cause real problems in code that depends on CFEXIT to terminate a process, such as in an included error-handling code fragment. Note also that CFEXIT has a new "method" attribute that can change its behavior still further.

Other Improvements
Still other changes fix limitations from previous releases. For instance, CFFILE now supports an "AddNewLine" attribute for the "Write" and "Append" actions. Set it to "No" to suppress adding a trailing newline character to the output. It defaults to "Yes" for backward compatibility. Those who tripped over this issue previously will be delighted by the news. And those who tried in previous releases to use CFPARAM to change a URL or FORM variable found that it wasn't allowed. In CF 4.0, these scopes are no longer read-only. This now makes it easy to indicate a default value for a URL or FORM variable if none is provided in the calling template. (The CGI scope remains read-only.)

A new CFSETTING option called SHOWDEBUGOUTPUT can control the display of debugging data within portions of a template when debugging has been turned on in the Administrator. And finally, a new variable called EXECUTIONTIME is available for CFQUERY. Used as QUERY.EXECUTIONTIME (not a "queryname." prefix), it returns the time it took for the last query to execute.

There are many other minor improvements like these. See the Release Notes, mentioned below, for more information.

Finding Out More
There are several ways you can learn more about CF 4.0. Of course, the documentation is always a good place to start in regard to technical details (and the docs in CF 4.0 have been improved substantially, with more examples, more detail and even new books). You can view these online at www.allaire.com/Documents/cf4docs.cfm.

In addition to CFDJ, there are also Release Notes that explain several other issues of note at www.allaire.com/documents/cf4/allaire_support/releasenotes.cfm, as well as a "New Features" document that can be found at www.allaire.com/documents/cf4/allaire_support/cf4features.cfm.

If you stop at those, however, you'll be missing out. Another important document you should read is called the "Documentation Update." You can find it at www.allaire.com/documents/cf4/allaire_support/cf4doc_update.cfm. This not only lists corrections to the printed docs but, even more important, it lists some new features that weren't documented at all.

About 4.0.1 I'd previously mentioned some features that Allaire has publicly pledged to support in release 4.0.1, which is in beta as of this writing. Because of nondisclosure agreements, I can't release specifics regarding the update, but it's more than just a set of bug fixes. Be sure to check it out when it arrives. One thing I think I'm safe to speak of is that the hassle of not being able to test both the existence of a variable and its value in a single CFIF statement will soon be history. That makes 4.0.1 a must-have! Watch for it soon.

With 4.0, Allaire created a solid platform for the next generation of commerce-ready Web applications and has taken another step toward becoming the worldwide leader in platform-independent Web development tools and application servers.