topic Re: Conditional dropdown in Tool Validator based on user input in Python Questions

Conditional dropdown in Tool Validator based on user input

AllisonClark — Sat, 11 Dec 2021 12:00:54 GMT

This picks up from Conditional Drop Down Lists - Tool Validator

My basic question is, how do you write a script tool parameter window that takes data entry input as a filter on a feature class field? And then lets the user select values from the filtered output.

My script tool is meant to prompt the user to enter the first six digits of a parcel ID, such as '0401 01' and then uses that to filter a list of parcels pulled from the PARCELS_BASE feature class. I tried to reuse the code from https://community.esri.com/thread/210869-conditional-drop-down-lists-tool-validator

because it's similar, but could not get it to filter based on data entry.

Here's my most recent iteration. In my situation, the feature class and field are fixed, so I tried substituting in the hard-coded names, leaving just the one input parameter, GridQuadDbl, for user data entry. I expected this to display the filtered list as the OutValue. All I got was an error on the line where I invoked SearchCursor, saying that NoneType object has no attribute 'list'. That's going to be something dumb and obvious, but it's insane trying to debug inside Tool Validator, and it's late, and I'm tired.

First, the attribute table, with PIN being the field where I'm trying to filter the results:

The parameter window when you run the tool:

Next, the parameters (ignore debugger)

The code:

class ToolValidator(object):

    def __init__(self):
        self.params = arcpy.GetParameterInfo()

    def initializeParameters(self):
        
    def updateParameters(self):
        # set values for fc and field
        fc, col = "PARCELS_BASE", "PIN"

        # get value for grid-quad-dbl
        if self.params[0].value:
            wc = "{0} LIKE '{1}%'".format(col, str(self.params[0].value))
            self.params[2].value = wc
            self.params[1].filter.list = [str(val) for val in sorted(
                set(row.getValue(col) for row in arcpy.SearchCursor(fc, fields=col, where_clause=wc)))]

        if self.params[1].value not in self.params[1].filter.list:
            self.params[1].value = self.params[1].filter.list[0]

        return

Re: Conditional dropdown in Tool Validator based on user input

RandyBurton — Sat, 11 Dec 2021 12:00:56 GMT

I was experimenting with some code that uses a LIKE in the where clause. It pulls parts of the PIN from the data and loads it into dropdowns for the user to select from. Hopefully, it is similar enough to your project that it will give you some ideas. Here's the validator section:

import arcpy
class ToolValidator(object):

    def __init__(self):
        import arcpy
        self.params = arcpy.GetParameterInfo()

    def initializeParameters(self):
        # (initializeParameters code here)
        return

    def updateParameters(self):

        if self.params[0].value: # feature has been selected
            useFields = ['PIN'] # name of field used by tool (parcel identification number - a string)
            desc = arcpy.Describe(self.params[0].value)  # information about the input feature
            fieldNames = { f.name: f.type for f in desc.fields } # dictionary used to keep field names and types together

            if set(useFields).issubset(fieldNames.keys()): # all fields were found by tool


                # NOTE: if any selections have been made in fc, then only selected features will be searched
                fc, fld = str(self.params[0].value), useFields

                self.params[1].filter.list = sorted(set([f[0][:4] for f in arcpy.da.SearchCursor(fc,fld)]))
                if self.params[1].value not in self.params[1].filter.list:
                    self.params[1].value = self.params[1].filter.list[0]

                where_1 = "PIN LIKE '{}%'".format(self.params[1].value)
                
                self.params[2].filter.list = sorted(set([f[0][5:7] for f in arcpy.da.SearchCursor(fc,fld,where_1)]))
                if self.params[2].value not in self.params[2].filter.list:
                    self.params[2].value = self.params[2].filter.list[0]

                where_2 = "PIN LIKE '{} {}%'".format(self.params[1].value, self.params[2].value)

                self.params[3].filter.list = sorted(set([f[0][8:] for f in arcpy.da.SearchCursor(fc,fld,where_2)]))
                if self.params[3].value not in self.params[3].filter.list:
                    self.params[3].value = self.params[3].filter.list[0]

                # output completed whereClause
                self.params[4].value = "PIN = '{} {} {}'".format(self.params[1].value, self.params[2].value, self.params[3].value)

            else: # at least one of the field names does not exist in feature; using the parameter to hold an error message

                if 'PIN' not in fieldNames.keys():
                    self.params[1].value = "ERROR: Field 'PIN' not in selected feature class."

        return

    def updateMessages(self):
        
        self.params[0].clearMessage()
        self.params[1].clearMessage()
        self.params[2].clearMessage()
        self.params[3].clearMessage()
        if self.params[0].value is not None: # set error message if field not in feature so user can correct problem

            if self.params[1].value is not None:
                if self.params[1].value.startswith("ERROR:"):
                    self.params[1].value = None # clear error message in parameter value, if desired
                    self.params[1].setErrorMessage("Field '{}' is not in Input FC '{}'".format('PIN', self.params[0].value))

        return
‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

For my testing, I used the following script:

import arcpy

inFC = arcpy.GetParameterAsText(0) # input feature class (Input, Data Type 'Feature Layer')
PIN_a = arcpy.GetParameterAsText(1) # PIN[:4]  (Input, Data Type 'String')
PIN_b = arcpy.GetParameterAsText(2) # PIN[5:7] (Input, Data Type 'String')
PIN_c = arcpy.GetParameterAsText(3) # PIN[8:]  (Input, Data Type 'String')
whereClause = arcpy.GetParameterAsText(4) # set by ToolValidator updateParameters (Output, Derived, Data Type 'String')

arcpy.AddMessage("Where clause used: {}".format(whereClause)) 
arcpy.SelectLayerByAttribute_management(inFC, "NEW_SELECTION", where_clause=whereClause)

for i in range(arcpy.GetMessageCount()):  # display messages from SelectLayerByAttribute tool
    arcpy.AddMessage(arcpy.GetMessage(i))

n = arcpy.GetCount_management(inFC)
arcpy.AddMessage("Number of records selected: {}".format(n))‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

Hope this helps.

Re: Conditional dropdown in Tool Validator based on user input

AllisonClark — Mon, 16 Nov 2020 02:42:02 GMT

Randy, wow thanks! Your code worked beautifully, ran the Toolvalidator script and then my main geoprocessing script seamlessly. I am reworking it now to display a list of full-length parcels in the 3rd param and then let the user select multiple parcels for running the script. I will post it once I get it working with my changes.

But I have a question on debugging the ToolValidator. How do you structure it so that you can run it as a script in an IDE (Pycharm in my case)?

I had earlier tried setting it up using the example at the bottom of this page: https://desktop.arcgis.com/en/arcmap/latest/analyze/creating-tools/debugging-a-toolvalidator-class.htm

Then I tried the script you posted at the bottom of your post. Then I tried combining the two. They handle the parameters differently, so I tried it both ways. The problems are mostly about accessing the parameters and feeding them into the Tool Validator script. Here's the debug script. What am I not understanding?

# DEBUGGING SCRIPT FOR TOOLVALIDATOR CODE - 11/15/2020

# create parameter array and values
import arcpy
# Load the toolbox and get the tool's parameters, using the tool name (not the tool label).
tb = r"G:\projects\ocp\pd\env_wetlands\Env_Assessment_maps\Map_compositions\Environmental_Map_Template_dev2\Parcel or Address Search.tbx"
arcpy.ImportToolbox(tb)
params = arcpy.GetParameterInfo("RequestParcelInput")

# set required parameters
# params[0].value = "PARCELS_BASE"
# params[1].value = "0401 01"
# params[2].value = "0401 01  0001"

inFC = arcpy.GetParameterAsText(0)      # input feature class (Input, Data Type 'Feature Layer')
PIN = arcpy.GetParameterAsText(1)       # PIN[:8]  (Input, Data Type 'String')
PIN2 = arcpy.GetParameterAsText(2)      # full PIN (Input, Data Type 'String')
whereClause = arcpy.GetParameterAsText(3) # set by ToolValidator updateParameters (Output, Derived, Data Type 'String')

# arcpy.AddMessage("Where clause used: {}".format(whereClause))
arcpy.SelectLayerByAttribute_management(inFC, "NEW_SELECTION", where_clause=whereClause)
for i in range(arcpy.GetMessageCount()):  # display messages from SelectLayerByAttribute tool
    arcpy.AddMessage(arcpy.GetMessage(i))
# n = arcpy.GetCount_management(inFC)
# arcpy.AddMessage("Number of records selected: {}".format(n))‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍‍

#########################################################################################

class ToolValidator(object):
    """Class for validating a tool's parameter values and controlling
    the behavior of the tool's dialog."""

    def __init__(self😞
        """Setup arcpy and the list of tool parameters."""
        self.params = arcpy.GetParameterInfo()

    def initializeParameters(self😞
        """Refine the properties of a tool's parameters. This method is
        called when the tool is opened."""

    def updateParameters(self😞
        """Modify the values and properties of parameters before internal
        validation is performed. This method is called whenever a parameter
        has been changed."""

        if self.params[0].value:  # feature class has been selected
            useFields = ['PIN']  # name of field used by tool (parcel identification number - a string)
            desc = arcpy.Describe(self.params[0].value)  # information about the input feature
            fieldNames = {f.name: f.type for f in desc.fields}  # dictionary used to keep field names and types together

            if set(useFields).issubset(fieldNames.keys()):  # all fields were found by tool
                # NOTE: if any selections have been made in fc, then only selected features will be searched
                fc, fld = str(self.params[0].value), useFields
                # GQD unique-values filter from all parcels in PARCELS_BASE
                self.params[1].filter.list = sorted(set([f[0][:7] for f in arcpy.da.SearchCursor(fc, fld)]))
                if self.params[1].value not in self.params[1].filter.list:
                    self.params[1].value = self.params[1].filter.list[0]

                wc = "PIN LIKE '{}%'".format(self.params[1].value)
                self.params[5].value = "querystring: " + wc  # display to debugger

                self.params[2].filter.list = sorted(set([f[0][:] for f in arcpy.da.SearchCursor(fc, fld, wc)]))
                if self.params[2].value not in self.params[2].filter.list:
                    self.params[2].value = self.params[2].filter.list[0]

                # output completed whereClause
                self.params[3].value = "PIN = '{}'".format(self.params[2].value)
                # self.params[3].value = "PIN = '{} {}'".format(self.params[1].value, self.params[2].value)
                self.params[5].value = self.params[3].value  # display to debugger

            else:  # at least one of the field names does not exist in feature; using the parameter to hold an error message

                if 'PIN' not in fieldNames.keys():
                    self.params[1].value = "ERROR: Field 'PIN' not in selected feature class."

        return

    def updateMessages(self😞
        """Modify the messages created by internal validation for each tool
        parameter. This method is called after internal validation."""

        self.params[0].clearMessage()
        self.params[1].clearMessage()
        self.params[2].clearMessage()
        self.params[3].clearMessage()
        self.params[4].clearMessage()
        self.params[5].clearMessage()

        if self.params[0].value is not None:        # set error msg if field not in feature so user can correct problem
            if self.params[1].value is not None:
                if self.params[1].value.startswith("ERROR:"😞
                    self.params[1].value = None     # clear error message in parameter value, if desired
                    self.params[1].setErrorMessage(
                        "Field '{}' is not in Input FC '{}'".format('PIN', self.params[0].value))

        return

    def isLicensed(self😞
        """Set whether tool is licensed to execute."""
        return True

#########################################################################################
# Below Toolvalidator code, create Toolvalidator class and call UpdateParameters + messages
validator = ToolValidator()
validator.updateParameters()
validator.updateMessages()

Re: Conditional dropdown in Tool Validator based on user input

RandyBurton — Mon, 16 Nov 2020 23:38:45 GMT

Here's the script I used for debugging my Tool Validator code. Since it is tested outside ArcMap, there are some modifications that are necessary. For example, a full path to the feature containing your PINs is needed.

# HELP at http://desktop.arcgis.com/en/arcmap/latest/analyze/creating-tools/debugging-a-toolvalidator-class.htm import arcpy # Load the toolbox and get the tool's parameters, using the tool # name (not the tool label). # arcpy.ImportToolbox(r"C:\Path\to\toolbox.tbx") # toolbox location params = arcpy.GetParameterInfo("SearchParcel") # name of script (not tool label) # Set required parameters # params[0].value = r"C:\Path\to\geodatabase.gdb\PARCELS_BASE" # feature layer # params[1].value = '0401' # first part of PIN # params[2].value = '02' # middle part of PIN # ToolValidator class block # ---------------------------------------------------------------- class ToolValidator(object): def __init__(self): import arcpy self.params = arcpy.GetParameterInfo() def initializeParameters(self): # (initializeParameters code here) return def updateParameters(self): if self.params[0].value: # feature has been selected useFields = ['PIN'] # name of field used by tool (parcel identification number - a string) desc = arcpy.Describe(self.params[0].value) # information about the input feature print(desc.dataType) # # Debug # # fieldNames = { f.name: f.type for f in desc.fields } # dictionary used to keep field names and types together print(fieldNames) # # Debug # # if set(useFields).issubset(fieldNames.keys()): # all fields were found by tool print("Field found in feature class") # # Debug # # # NOTE: If feature has selections, only the selections will be searched fc, fld = str(self.params[0].value), useFields self.params[1].filter.list = sorted(set([f[0][:4] for f in arcpy.da.SearchCursor(fc,fld)])) if self.params[1].value not in self.params[1].filter.list: self.params[1].value = self.params[1].filter.list[0] print(self.params[1].filter.list[0]) # # Debug # # print(len(self.params[1].filter.list)) # # Debug # # print(self.params[1].filter.list) # # Debug # # where_1 = "PIN LIKE '{}%'".format(self.params[1].value) print(where_1) # # Debug # # self.params[2].filter.list = sorted(set([f[0][5:7] for f in arcpy.da.SearchCursor(fc,fld,where_1)])) if self.params[2].value not in self.params[2].filter.list: self.params[2].value = self.params[2].filter.list[0] print(self.params[2].filter.list[0]) # # Debug # # print(len(self.params[2].filter.list)) # # Debug # # print(self.params[2].filter.list) # # Debug # # where_2 = "PIN LIKE '{} {}%'".format(self.params[1].value, self.params[2].value) print(where_2) # # Debug # # self.params[3].filter.list = sorted(set([f[0][8:] for f in arcpy.da.SearchCursor(fc,fld,where_2)])) if self.params[3].value not in self.params[3].filter.list: self.params[3].value = self.params[3].filter.list[0] print(self.params[3].filter.list[0]) # # Debug # # print(len(self.params[3].filter.list)) # # Debug # # print(self.params[3].filter.list) # # Debug # # # output completed whereClause self.params[4].value = "PIN = '{} {} {}'".format(self.params[1].value, self.params[2].value, self.params[3].value) print(self.params[4].value) # # Debug # # else: # at least one of the field names does not exist in feature; using the parameter to hold an error message if 'PIN' not in fieldNames.keys(): self.params[1].value = "ERROR: Field 'PIN' not in selected feature class." print(self.params[1].value) # # Debug # # return def updateMessages(self): self.params[0].clearMessage() self.params[1].clearMessage() self.params[2].clearMessage() self.params[3].clearMessage() if self.params[0].value is not None: # set error message if field not in feature so user can correct problem if self.params[1].value is not None: if self.params[1].value.startswith("ERROR:"): self.params[1].value = None # clear error message in parameter value, if desired self.params[2].value = None self.params[3].value = None self.params[0].setErrorMessage("Field '{}' is not in Input FC '{}'".format('PIN', self.params[0].value)) print('Setting message 0') # # Debug # # return # ---------------------------------------------------------------- # Call routine(s) to debug # validator = ToolValidator() validator.updateParameters() validator.updateMessages() print('\n') for p in params: print(p.name, p.datatype, p.parameterType, p.direction, p.value) print('\n') # tool script (modified for debugging): inFC = params[0].value # arcpy.GetParameterAsText(0) # input feature class (Input, Data Type 'Feature Layer') PIN_a = params[1].value # arcpy.GetParameterAsText(1) # PIN[:4] (Input, Data Type 'String') PIN_b = params[2].value # arcpy.GetParameterAsText(2) # PIN[5:7] (Input, Data Type 'String') PIN_c = params[3].value # arcpy.GetParameterAsText(3) # PIN[8:] (Input, Data Type 'String') whereClause = params[4].value # arcpy.GetParameterAsText(4) # set by ToolValidator updateParameters (Output, Derived, Data Type 'String') arcpy.AddMessage("Where clause used: {}".format(whereClause)) print("Where clause used: {}".format(whereClause)) # # Debug # # # convert inFC to feature layer since we are outside arcmap arcpy.MakeFeatureLayer_management(inFC,'inFC_layer') # use layer created arcpy.SelectLayerByAttribute_management('inFC_layer', "NEW_SELECTION", where_clause=whereClause) for i in range(arcpy.GetMessageCount()): # display messages from SelectLayerByAttribute tool arcpy.AddMessage(arcpy.GetMessage(i)) # print messages created by SelectLayers print(arcpy.GetMessages()) # # Debug # # n = arcpy.GetCount_management(inFC) arcpy.AddMessage("Number of records selected: {}".format(n)) print("Number of records selected: {}".format(n)) # # Debug # #

You will notice that I've added some print statements inside the Tool Validator. Normally I wouldn't try to debug the tool's script while working on the validator's code, but it can be placed at the bottom and will need some modification. Even then, you may get some unexpected results.

For testing the params (just before the validator class), I started with just the feature and added parts of the PIN to see what changes this would make.

Hope this helps.

Re: Conditional dropdown in Tool Validator based on user input

AllisonClark — Wed, 02 Dec 2020 21:44:36 GMT

Hello Randy,

I've been stuck on a weird problem with resetting the filters. The dropdowns that draw from the PARCELS_BASE feature layer work beautifully until I actually run the tool script. Thereafter, the dropdowns only show the parcel ID that was used by the script. The only way to reset them is to close the project and reopen it.

The attachment shows an example.

I checked the PARCELS_BASE table; my script does a CLEAR SELECTION on it, and nothing is still selected.

I didn't find much online on the topic of resetting filter lists drawn from the database, and nothing at all about using them in ToolValidator.

I tried these statements in different places to no effect:

self.params[1].filter.list = []

cursor.reset() (where cursor = arcpy.da.SearchCursor())

What am I missing?

Re: Conditional dropdown in Tool Validator based on user input

AllisonClark — Thu, 03 Dec 2020 02:58:57 GMT

Update: It looks like I need to put SelectLayerByAttribute("PARCELS_BASE", "CLEAR_SELECTION") into the ToolValidator code specifically?? I tried debugging in the Pro python window and found that worked.

Re: Conditional dropdown in Tool Validator based on user input

RandyBurton — Thu, 03 Dec 2020 03:40:33 GMT

Yes, the tool should clear the selection. Typically, this would be when things complete. The user would need to manually clear any selections before reusing the tool, or the next use of the tool would be limited to the selections.

If it is important to see the selected feature after running the tool, I suppose you could insert the "clear selection" instruction at the start of the tool validator code. The idea would be to clear any selections before populating the drop-downs.

I could also see that allowing the user to select a group of features to search may help performance if there are lots of parcels and only a specific neighborhood needs to be searched. Then the user would need to know if the dropdown doesn't contain enough selections, then exit the tool, clear any selections and try again.

Re: Conditional dropdown in Tool Validator based on user input

RandyBurton — Thu, 03 Dec 2020 03:52:48 GMT

If you want to clear selections in the Tool Validator section, you might try:

def updateParameters(self): if self.params[0].value: # feature has been selected arcpy.SelectLayerByAttribute_management(self.params[0].value, "CLEAR_SELECTION") # code continues