Tango 3.1 for FileMaker

Sunday 28th June, 1998

Before the Web-enabled FileMaker Pro 4.0, there was Tango. With a copy of FileMaker Pro 3.0 and Tango, you could build interactive Web sites based on the data in your FileMaker databases without the need for a single line of CGI script or a degree in Perl. As a result of Tango’s success, Claris incorporated a rival Web-enabling technology into version 4.0, giving every FileMaker user the ability to publish their data on the Web. It’s not as robust as Tango and it’s not multithreaded, but for the majority of us it’s OK.

Now Everyware has released Tango 3.1. The previous version, while innovative, was flawed. Perhaps the most important of the ‘60 new features’, conditional execution steps (‘if … then … else’) gives you some idea of the old version’s weak points. However, most of the flaunted new features are worth shouting about.

Tango is immensely powerful, but installation can be a nightmare depending on the Web server you’re using - during installation it doesn’t like Quid Pro Quo, for example - and the manuals aren’t much help.

Tango comes in two parts: the Tango Editor, which lets you create self-contained program files made up of steps called Tango Action Files (.taf), and the Tango Server, which does the real work. In terms of software, the Tango Server is the middleman’s middleman. It sits between a standard http Web server, such as WebStar, and your database, which in our case was FileMaker. When a user’s browser sends a GET request, which is a URL to a Tango .taf file plus any parameters or search arguments, the Web server hands this request straight over to the Tango Server. The .taf file, which contains code previously written in the Editor, is then executed. If necessary it talks to the FileMaker database, reading and writing data to specified files. When it’s finished it returns any results to the Web server which in turn passes them on to the user.

Anyone who’s used the FileMaker Web Companion may feel there are certain similarities in the process. This is mainly due to the nature of the client/server model itself. There are a number of important differences. First, the code that queries the database is stored in the .taf file. In fact, a .taf file can be used to create a number of different pages based on the parameters passed to it and the state of any databases accessed by it. Second, the use of a standard Web server, as opposed to a helper application like Web Companion, means the bulk of the processing is multithreaded, giving marked improvements in user response time.

Unlike the current version of FileMaker, the functionality of the Tango Server can be easily customised and extended through JavaScript executed on the server or at the client end, and directly executed external actions - server-side JavaBeans and Java Class execution, AppleScript, a Mail action for sending SMTP based emails, the FileMaker script action, and the File Action - which allows you to read, write and delete files on the Server. All of these actions provide the Web designer with another set of functional possibilities denied to users of Web Companion. Being able to read and write text files should allow users to update databases more easily from online data sources, for example. As well as actions, Tango supports a whole new variable type for supporting arrays (tables) of information, and metatags for including date and time, browser and information, and maths calculations on Web pages.

Aside from functionality, the biggest improvements are to the Editor’s user interface. The control statements are the most obvious example, but Tango also lets you group actions and then hide them in the outline editor. Tango includes two Builders, which let you construct groups of actions for creating records and searching for records, greatly simplifying the task. The Tango Editor also provides Snippets - small pre-written bits of HTML code that you can drag and drop from a list into your .taf files. There are a number of Snippets provided which you can edit or add to.

Tango is cross-platform; the server runs on Windows NT and 95, Solaris, IRIX, AIX and other flavours of Unix. There are differences between the platforms in terms of external actions, but Everyware makes it clear that avoiding those elements should allow you to produce scalable .taf files. And Mac users have a price advantage - the Windows server is £3325, and Unix’s £6650.

Verdict

Build interactive Web sites based on your FileMaker databases without having to use code.