Simplifying Web Services Description Language (WSDL) Editing
By Leon Barnard on Sep 16, 2007
Leon Barnard is an Interaction Designer in xDesign, who is working on SOA/BI and NetBeans products. He recently moved from Los Angeles to Prague and is enjoying Czech food and not needing a car.
My job as an interaction designer is to create designs that help users accomplish their tasks more quickly and/or more easily. Sometimes this is done through surface-level changes like adding emphasis to frequently used actions, adjusting spacing and layout, or by using clearer instructions. The most successful projects, however, often involve taking a very complex task and changing its components so that achieving the desired result becomes less complex. This is much more difficult to do, yet more fun and rewarding. I was recently tasked with making the development and design of WSDL files easier. Since the task is so complex, I wanted to try to devise a better way of accomplishing it that would help novices learn the technology, as well as help experts focus on what they care about most.
WSDL ("Web Services Description Language") is a complex language used to create web services. Web services are computer programs that can be used by many different organizations or individual programmers, to perform a function they can’t perform themselves or perhaps that they don’t want to try and recreate themselves. An infinite variety of transactions and queries can be conducted quickly and efficiently without requiring any special software or network configuration. WSDL has a standard format for taking a request, processing the request, and then providing a response to the source of the request. The processing part is where a company, like Google, would provide its program’s function (called a “service”, or “web service” in this world). While the format is standard and predictable, it’s also created with the computer, not the human, in mind. So the syntax is relatively complex and unintuitive for most less-than-expert folks.
These characteristics of WSDL syntax distract users from their primary task and add confusion, especially for novices. The precise 'what', 'how', and 'where' that the user is concerned with takes up relatively little space in the code. Ideally, this content would take precedence, and the rest would go to the background or, even better, be handled "behind-the-scenes" automatically.
Our design addresses these issues. The biggest change that we made to the existing editor was to move to a more visual, connection-based presentation. In this way, users can see, even at a glance, which pieces were connected to which, allowing them to follow the stream of connections across the file. It prevents errors of mis-typing the names of objects to be connected, because creating a visual connection automatically writes the appropriate code for the user. Next, the core 'what', 'how', and 'where' elements are represented as salient visual objects that draw the user's attention, while the container objects are shown simply as dotted lines surrounding their contents. These visual representations allow users to easily see what they care about most, yet also understand how they are grouped. Finally, some workflow improvements were added to train novice WSDL users and save time for both experts and novices. These include: dragging-and-dropping from a palette, previewing valid drop locations, automatically creating objects and their containers (if necessary) when a connection is made, prompting for necessary configuration information when certain types of objects are added, and being able to collapse groups of objects that are not being worked on, among others.
In summary, the new design offers the following benefits:
- Uses a flow/connection-based model for visualization.
- The focus is on the meaningful elements (not the "container" elements).
- Follows the principle of "recognition rather than recall".
- Drag-and-drop for faster and more intuitive use.
- Multiple steps can be performed at once.
- Is more discoverable and approachable for novices.
Here are some more snapshots of the new design: