Friday, July 01, 2005

Formula's in Property Sets

I have found that users of ADT that have never programed generally have probelms using formula's in property sets. They can be very simple and yet so powerful. They allow you to make decisions on the fly and show alternative information based on comparing properties.

To use an example is always the best way. If you are new to ADT of customisation, try to create the properties in this example and then try to pull it apart. You will learn much more by destroying something that works and then trying to put it back together.

Here we are going to put a property set to lines that represent bracing walls. Yes you can use simple elements - they don't always have to be AEC objects. Make a propety set called bracing and make them attach to lines. Now its time to create the properties with the data that we can schedule. Remember we are going to use formulas - here is why . . . . .

When we do bracing walls there are a couple of types
1. Calculated - the total strength is based on racking\m X length
2. Actual - These have a value based on standard tested results i.e columns

To have these appear in the same schedule we need to be able to distinguish between them BUT still put them in the same schedules. To do this we create a property that shows if it is calculated or actual. From here other properties will be changed dependant upon this tag and this is the formula part. Here are the properties




The important part here is the formula for STRENGTH it reads


If [panel] Then RESULT = [Length] *[racking] Else RESULT = [racking]

Try drawing a line and them manually attaching the property set to it. When you do you can then change the properties to reflect the type of bracing wall - is a panel wall. If it is NO it then takes the value of the racking without multiplying the length to get the strength. This is the IF statement in the strength column and the calculation is appropriate.

Try scheduling it see what happens. Here's some homework - make another tag and make it read for the type of bracing wall in text - Panel or column ????

I know this is a simple example but not everyone wants to start at the top. I think some of the advanced users forget this. We are not hear to show how big our ego's are by using big formula's or comple example . . . . my aim is to palnt the seen in your mind. It's up to you to make it grow and water the seed . ..