Digital Workshop Opus Pro

Digital Workshop's Opus authoring tool, released earlier this year, was a rewrite of its popular but ageing Illuminatus 4.5. Opus quickly carved out a niche as the lowest-priced multimedia-programming tool with a good feature set. Initially problematic, Opus has become progressively more stable with each Service Pack, but can still perform in unexpected ways, making it a risky choice for corporate work.

From the outset, Digital Workshop planned to launch a beefed-up version aimed at professional multimedia authors. Unlike MatchWare, which sees its Mediator EXP (see p187) product as a potential replacement for Director, Digital Workshop sees Opus Pro as a complement to Director (version 8.5 reviewed issue 80, p182) and has priced it accordingly.

As with Mediator EXP, the main addition to the Pro version of Opus is scripting. Unlike Mediator, however, the Opus programming language, OpusScript, is entirely internal. This makes it even easier to implement and distribute, as the end user doesn't need the Microsoft Scripting Engine. The whole process feels more integrated.

OpusScript is based on the ECMA standards formed around JavaScript, so Web programmers and users of Flash's ActionScript will find OpusScript familiar. Unfortunately, this doesn't necessarily make OpusScript particularly easy for the novice programmer to learn. For example, OpusScript is case sensitive but doesn't generate useful error messages where case has been used wrongly. Even worse, both the manual and Help file are littered with documentation errors. Commands are described incorrectly, the examples are often incorrect and, worst of all, some commands are plain wrong. Some just don't work at all.

An experienced programmer will find this frustrating; a less experienced programmer might well be defeated. These problems are exacerbated by rudimentary syntax checking and extremely unhelpful error messages.

However, get beyond the frustration and you'll find a fully featured programming language. OpusScript gives you control of all the objects on the page. Unlike Mediator, it doesn't allow global scripts; OpusScript code can only be attached to the page or any object.

OpusScript offers even finer control over your objects than Mediator EXP. You can roll, rotate, spin, skew and scale any visible object. Perhaps most usefully, OpusScript includes the CloneObject command that creates a new instance of any object so that if you were creating a Space Invaders game, for example, you could create a single alien and duplicate at run-time. That said, Opus Pro isn't the right tool for game creation: it just doesn't offer enough performance.

Opus Pro includes support for ODBC databases, and OpusScript's database commands allow you to move through a database, find a record or execute any SQL command. This support is more sophisticated than Mediator EXP's, although the end user will need the appropriate drivers for the database format you're using. Stick to Access format and you're likely to be okay on any moderately recent PC with a standard Windows installation.

Compared to Opus Standard, Pro includes a range of new, more sophisticated actions. These include better variable handling, file open/browse capabilities, looping, CASE statements without programming and custom triggers.

It's in Internet deployment, however, that Pro really wins out over Mediator EXP. Digital Workshop has made the entire process of publishing on the Web as simple as possible. All scripting functions work with the exception of those that aren't permitted in the Internet environment such as file copying and executing.