topic Re: Creating branches and options in model builder in Geoprocessing Questions

Creating branches and options in model builder

frans-joostboogert — Wed, 27 Jun 2012 15:14:37 GMT

Hello fellow ArcGIS users,

I´m using ArcMap 10.
I have been trying to include some options in a model I want to run.
At the moment I have gotten to the point where I can get a drop-down list with names as a model parameter in the modelbuilder.
The problem I´m having now is that I can´t figure out how to get a condition to work as follows:
If condition one is true (user selects option1) than go to this branch of the model.
Else go to next if statement.

I hope this is enough information, thank you in advance this would help out a lot!
Frans-Joost

Re: Creating branches and options in model builder

JonathanQuinn — Wed, 27 Jun 2012 15:46:52 GMT

Here are a couple of resources that might get you in the right direction, I'm not sure if you've checked them out or not:

Branching: Implementing if-then-else logic

Branching with If-then-else logic in ModelBuilder

The first is the logic behind branching and included an if-else script in a model, and the second is a download from the Resource Center with a sample you can test with.

Re: Creating branches and options in model builder

ShitijMehta — Wed, 27 Jun 2012 22:15:12 GMT

There is a series of blogs on if-then-else blogs for 10 that will help you.
If you are stuck at "if" �?? Part 1
If you are stuck at "if" �?? Part 2 �?? Example of using Script tool to create branches using if-else logic
If you are stuck at "if" �?? Part 3 �?? Does Extension Exists model example
If you are stuck at "if" �?? Part 4 �?? Does Selection Exists model example
If you are stuck at "if" �?? Part 5 �?? Does Projection Exist model example

Re: Creating branches and options in model builder

frans-joostboogert — Thu, 28 Jun 2012 10:37:09 GMT

Thank you for the fast replies,
I have been looking at both solutions offered but I´m not sure if the calculate value tool is the right one for what I´m trying.
The script is as follows:

# Import system modules
import arcpy

     # Get input arguments - table name, field name
Equation = arcpy.GetParameterAsText(0)
Input = arcpy.GetParameterAsText(1)
    #check if equation is chosen:
     if Input == Equation:
         arcpy.SetParameterAsText(2, "True")
         arcpy.SetParameterAsText(3, "False")
     else:
         arcpy.SetParameterAsText(2, "False")
         arcpy.SetParameterAsText(3, "True")

But I get an error saying there is a problem with the if statement.
Both inputs are defined as strings but "input" is chosen from a drop down list when the model starts.