Script tool with drop down list of multi values using ToolValidator

[Aнастасия88]

Hello,

I need an idea on how to enable a drop down list in a script tool so that I can select multiple attribute values from a selected field.

Based on a code from ArcGIS blog, "Generating a choice list from a field", I managed to create a script tool with ToolValidator function to make a a drop down list.

But I cannot select multiple values with this code only. I can check the box of "Multiple values" in Parameters section. This makes multiple values windows but even if I select multiple values, the values won't be included as inputs. So, I feel the script in validation section needs to be modified but I am struggling with that.

Thanks in advance.

[DanPatterson]

There are discussions here

Solved: Create Script Tool with Sortable Field Multi-Value... - Esri Community

and here

Solved: Using script tool parameters to update a multiple ... - Esri Community

My preference is to use "Custom tools" and do minor validation within the validation code contained in the tool.  You get a better link (without coding) and a visual representation of the dialog parameters that isn't available in "python tools" ... kind of a misnomer since both of them are "python" at their root in the new toolbox structure introduces in Pro 2.8 and evident in beta 2.9.

See the help topics within this general area

Comparing custom and Python toolboxes—ArcGIS Pro | Documentation

[Aнастасия88]

Hi Dan, thanks for your advice.

I had already created the script tool in the custom toolbox and applied the validation code that I found it from the blog. But this way does not give me multiple values selection from the selected field unfortunately.

[DanPatterson]

the blog was from 2011 and for ArcMap and the code link was no good, so I can only guess.

The parameter would have to be multivalue

Working with multivalue inputs—ArcGIS Pro | Documentation

so that would have to be set up in your script as either a list or a semicolon separated string

[Aнастасия88]

Thanks for your help again.

I tick a box for Multiple Values in parameter. The data type is String. I think prepared a script to take the input as multiple values but it still does not work. 

My script for the multivalue input is below:

BName = arcpy.GetParameterAsText(2)
BName_list = BName.split(";")

[DanPatterson]

Add an

arcpy.AddMessage(BName_list)

to see what it returns.  It should return a list of strings if it is semicolon delimited

[Aнастасия88]

My script is:

InputFeatureClass = arcpy.GetParameterAsText(0)
InputField = arcpy.GetParameterAsText(1)
InputValue = arcpy.GetParameterAsText(2)
InputValues = InputValue.replace("'","")
InputValue_list = InputValues.split(";")
arcpy.AddMessage("Input Values: {0}".format(InputValue_list))

My parameters - data type is string and ticked Multiple Values:

Interface of the script tool allows me to select multiple values:

But even if I added the checked values, input ends up like this - it won't be multiple value for some reason.

[DanPatterson]

As I indicated earlier, I prefer custom toolboxes.

Here is on of my tools that accepts multiple values... to get a complete lists of possible selections, I just click on the little arrow beside the input parameter name (class fields in the case) and you end up with a list of checkboxes so you don't have to select one at a time.

try clicking on your arrow beside "Value"

[Aнастасия88]

I think I created a script tool in same steps that are described here - "Creating a script tools in a custom tool box".

Created like this below

Do you mean this is not a "custom toolbox" that you mentioned?

As you can see the second picture above, I did open the drop -down list of values and checked multiple values and clicked "Add". However, it ends up with like the third picture, which is only one value is selected and I cannot add and change it. 

I don't know what I am missing...

[DanPatterson]

The multivalue selection returns a ";" delimited list and this is how I split it in the code

cls_flds = cls_flds.split(";")

There is no extra validation code, just what you see.  in my case "Field" was the case with multiple values desired