This page describes how to create Calculated Attributes in dRofus. Using the Calculated Attributes feature, you can build formulas dynamically using available dRofus fields to create additional fields. Calculated Attributes are available for Rooms, Items, Occurrences, and Products and allow you to build simple to very complex results. We explain how to do this for Room Calculated Attributes, and on this page, we will go over how this can be done for items. The Calculated Attribute Formats are the same across dRofus. A good baseline understanding of how Item Composite Text Attributes work is a great place to start since the rules can be combined with these attributes. The Room Subtraction Example was a simple one that could be applied to items, but we will go more complex for this example.
You need admin access to the database to create calculated attributes, as the setup is done in the Administration settings. Please refer to Project Administrator.
This feature can not be exported to xml or PDF, but is available in Excel Exports and Revit/ArchiCAD Add-On configurations.
Item If/Then Example
You might be familiar with if/then formulas if you have ever built complex rules in Excel. The syntax of IF-THEN is = IF (logic text, value if true, value if false). The first argument tells the function what to do if the comparison is valid. The second argument tells the function what to do if the comparison is false. A quick search on the internet will result in several examples of this concept. In our example, we will use several rules to pull from item data to inform some results. If you have ever tried to determine Door Calculations, you will want to bookmark this page and impress your office. Our team in Australia came up with this idea, and we all think it’s a great example of using item data to inform other decisions.
Here are the results of using the fields in blue (Item Data) to inform the results in red (Calculated Attributes).
Here is how each calculated attribute (in red) is determined and the formulas used.
Let’s start at the bottom and work our way up. Each wants to be grouped under Door Calculations, so they all use that Group label.
Structural Height is defined using simple addition. The Reveal Height is added to the Frame architrave. But where is the Reveal Height coming from? That is another calculated attribute. Yes, you can build formulas on top of other formulas.
Structural Width is also defined by our first If/then formulas using Reveal Height. The rule is if the Panel B width equals zero, meaning it has no width (or there is no second panel), then combine the Revel width with the Frame architrave, AND if there is a Panel B width, add the Frame architrave twice to gain the additional width needed for both panels including the Panel B width.
Reveal Width is also an if/then formula and incorporates the rules of the panel width and the panel width clearance from the Item Data. This is an if/then within an if/then formula where the first rules are checked, followed by a second set of rules. If Panel A is zero, then the reveal width is zero. If the Panel A width is not zero a second, If/then is checked to see the condition of Panel B. If Panel B is zero, then add Panel A to the Panel width clearance, and If Panel B is not zero, then add Panel A to Panel B plus two Panel width clearances.
Reveal Height is simply a combination of the Panel height and the floor finish allowance.
So far, These examples have helped define the Structural and Reveal requirements, which would be helpful to define in either a drawing set or for additional team members doing these types of calculations outside of dRofus. The best part is that this effort is automatically defined by filling in the item data.
Clear Opening is an example of taking values away from other fields to determine the space between an open door and the other side of the door and an important value when determining what equipment can fit during construction or during occupancy. In this example, we have another nested if/then formula. If Panel A is zero, we are not concerned about the opening since there is no door. If there is no width for Panel B, we subtract the Panel thickness, Frame Stop, and Hinge from Panel A. If Panel B is included, we add Panel B to Panel A and subtract the Panel thickness and Frame Stop twice to get a clear open when there are two panels.
The goal behind these examples is to give you a sense of what is possible using items and examples. There are several different Calculated Attribute Formats to explore.
Explore how to do this with Occurrence Calculated Attributes.