Product Reviews

4D has travelled a long way over the past 20 years. Starting life in the late 1980s as a powerful relational database, it spent along time in the shadow of FileMaker. Nowthe application has become as well known in its other role as a suite of tools for rapid development of local and remote programs. But here, too, there are better-known alternatives, either in the form of the powerful development tools built into Mac OS X, or the growing accessibility of SQL-based databases. So can a new version of 4D challenge these alternatives?

4D Developer is a cross-platform application that's available in three versions. The Standard edition comes with a development environment, and a web services client that lets you link to other services over a local or remote network using standard protocols. The Professional and Team versions include a web application server and a compiler to create fast-running standalone applications.

In all its guises, the program can be used either as a developer tool or as a database application by end users. This dual role is reflected by its two environments: Design - where you create and build the database - and Application, where you use it. You canquickly flip between modes through amenu option, which hugely simplifies testing during development.

The first step in creating a 4D application or database is to create its underlying tables and fields. 4D makes it easy to define relationships between fields of the same type by clicking and dragging from one to another. You can then design the program's interface with the Form Editor. This is nowhere near as polished as Apple Xcode's Interface Builder, but it's arguably more flexible. True to its cross-platform background, forms can be based on either Mac OS X or Windows interfaces. Mac OS X interface elements, from radio buttons to progress indicators, can be added by drawing them over the form window.

There are a number of practical improvements to the program since we last looked at it (MacUser, 29 September 2006, p61). The web services have been improved - there's now a neat wizard to make it easier to automatically create web service calls, and a new form area lets you display and control the sort of information that can be displayed by a web browser, from HTML pages to Flash animations. Searching and replacing is much simpler, too. You can now set multiple criteria and match types for your search, use wildcards and restrict the search to

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particular folders.

The arrival of the new Maintenance and Security Center makes it much easier to manage a database. Here, through a vertical toolbar, you can perform a number of cleanup tasks on your database, from basic table size analysis to automated backup and integrity checks. There's also abuilt-in repair tool that can fix corrupted ordamaged databases.

Historically, the biggest block to 4D adoption was its reliance on its built-in object-oriented programming language. Thebiggest change in this new version is that it now boasts its own SQL engine that lets you create SQL queries. For hardened 4D programmers, the advantages of SQL over 4D might not be immediately obvious -after all, 4D has its own query commands and the ability to interact with SQL databases is not new. However, SQL adds more flexibility to 4D's repertoire. In practical terms, it means that rather than relying on building arrays to link related queries, you can take advantage of SQL commands such as union and subquery to link, or access records within aparticular selection. The SQL engine is commendably tightly integrated, so you can implement SQL queries in a handful of different ways, froman immediate execute command for one-off SQL queries to wrapping a series inside a start/end SQL command. And, handily, both 4D and SQL can be used interchangeably inside a method, and you can employ SQL query results in 4D variables or fields.

Strategically, its inclusion is even more important, opening the program to a wider range of potential developers, as well as letting 4D interact natively with all manner of databases. And, crucially, reduced reliance on the venerable 4D language removes a potential disincentive to new users.

Another oft-cited drawback of 4D has been its steep learning curve. Here, the news is mixed. The documentation and built-in help are still frequently impenetrable, although a self-training manual helps with the basics. However, atleast there's a new startup wizard that optionally appears at launch, guiding you towards creating or opening a local or remote application. You can also use template databases as the basis for any new database.

Clearly the future of many databases lies in web accessibility, and although we didn't test its features, 4D now offers an optional Web 2.0 pack, a set of tools and plug-ins for higher-end versions of the program that let you integrate technologies such as Ajax and a component library for Adobe Flex 3, effectively allowing web access to a database and making it possible to use an iPhone as a database client.

Alongside its other improvements, the addition of SQL support, which makes 4D apowerful way to develop SQL applications, will probably be enough on its own to tempt existing users to upgrade. But while 4D retains a strong advantage in both the scalability of its development environment and the fact you can develop, test and run an application in the same workspace, its appeal will no doubt be limited by its price tag and continuing steep learning curve.