Continuing with my ShapeSheet Tips series (part 1, part 3), today I'm going to look at a tool that helps when trying to understand the relationships between cells within the Visio ShapeSheet - Formula Tracing...
Formula Tracing in Visio is similar to the feature found in Excel, albeit without the visual arrows. For complex shapes it's easy to lose track of which cells depend on, or are themselves depended on by other cells. The tool allows you to more easily identify those sets of relationships and this can be particularly useful when trying to add functionality to a shape that you're not familiar with.
For example, if open the ShapeSheet for the Executive shape from the Org Chart stencil and select Tools / Formula Tracing / ShapeSheet Formula Tracing Window you'll see the following:
From the above image you can see immediately that the selected cell (User.ShapeType) is referenced, or depended upon, by a number of other cells, both within this shape and others, and you'd need to bear those in mind before making any changes.
Using Formula Tracing
To get going with Formula Tracing you just need to select View / Formula Tracing Window from the ShapeSheet menubar and this will reveal the above window. It is also worth making sure the Formula Tracing toolbar is visible by the checking the respective item under View / Toolbars, which will display the following short button set:
The buttons (in order) allow you to show and hide the tracing window, show dependents of the selected cell, show the precedents of the selected cell, navigate back to the previously selected cell and to navigate forward.
Here's two more examples showing the difference between dependents and precedents:
The above image shows that the selected cell (Geometry1.X1) has one dependent - Geometry1.X5. To turn that round, Geometry.1X5 depends on Geometry1.X1 for its value.
Next we can look at precedents. In this image the only change is that I've checked the Precedents button in the toolbar and you can see that Geometry1.X1 depends on (or is preceded by) two cells - Width and Scratch.B1. For short formulae this isn't particularly useful information as you can already clearly see that in the formula itself. It really comes into its own when trying to break down much longer ones.
The final part of the Formula Tracing tool is its ability to navigate between cells. Double clicking one of the cells in the Tracing window changes the selection in the ShapeSheet to the respective cell. This feature, combined with the backwards and forwards toolbar navigation buttons, enable you to move around the ShapeSheet to see the relevant cells without all of the endless scrolling that this usually entails.
So, not a tool perhaps that you'd use every day but a very handy aid when you need to quickly understand how complex shapes work.