Arc Python add in - dynamic combo populate

Question

I am attempting my very first python add in. what I would like it to do is look at a feature class, look through the town field. when the user selects a town I want the next combo box to populate with the LABELTEXT field with all of the values in that town and when a LABELTEXT is selected zoom to that bad boy.

I dont know how to get the town return into the ComboClass2 class or build the query to filter based on the town result

class ComboBoxClass1(object): 
 """Implementation for addin2_addin.combobox (ComboBox)""" 
 def __init__(self): 
 self.editable = True 
 self.enabled = True 
 self.dropdownWidth = 'WWWWWWWWWWWWWWWW' 
 self.width = 'WWWWWWWWWWWWWWWW' 
 def onSelChange(self, selection): 
 layer = arcpy.mapping.ListLayers(mxd, "block_cards", df)[0] 
 a = arcpy.SelectLayerByAttribute_management(layer, "NEW_SELECTION", "town = '" + selection + "'""'") 
 return a 
 df.extent = layer.getSelectedExtent() 
 arcpy.RefreshActiveView() 
 def onFocus(self, focused): 
 global mxd 
 mxd = arcpy.mapping.MapDocument('current') 
 global df 
 df = arcpy.mapping.ListDataFrames(mxd, "Layers")[0] 
 layer = arcpy.mapping.ListLayers(mxd, "block_cards", df)[0] 
 arcpy.SelectLayerByAttribute_management(layer, "CLEAR_SELECTION") 
 self.items = [] 
 values = [row[0] for row in arcpy.da.SearchCursor(layer, ["town"])] 
 for uniqueVal in sorted(set(values)): 
 self.items.append(uniqueVal) 
class ComboBoxClass2(object): 
 """Implementation for addin2_addin.combobox (ComboBox)""" 
 def __init__(self): 
 self.editable = True 
 self.enabled = True 
 self.dropdownWidth = 'WWWWWW' 
 self.width = 'WWWWWW' 
 def onSelChange(self, selection): 
 layer = arcpy.mapping.ListLayers(mxd, "block_cards", df)[0] 
 arcpy.SelectLayerByAttribute_management(layer, "NEW_SELECTION", "town = '" + ComboBoxClass1.onSelChange() + "' AND LABELTEXT = '" + selection + "'" ) 
 df.extent = layer.getSelectedExtent() 
 arcpy.RefreshActiveView() 
 def onFocus(self, focused): 
 global mxd 
 mxd = arcpy.mapping.MapDocument('current') 
 global df 
 df = arcpy.mapping.ListDataFrames(mxd, "Layers")[0] 
 layer = arcpy.mapping.ListLayers(mxd, "block_cards", df)[0] 
 arcpy.SelectLayerByAttribute_management(layer, "CLEAR_SELECTION") 
 self.items = [] 
 values = [row[0] for row in arcpy.da.SearchCursor(layer, ["LABELTEXT"])] 
 for uniqueVal in sorted(set(values)): 
 self.items.append(uniqueVal) 

Answer 1

Thank you everyone for the responses. so much better than geonet. I was able to look like a maniac with the below code.

class ComboBoxClass1(object):
 """Implementation for addin2_addin.combobox (ComboBox)"""
 def __init__(self):
 self.editable = True
 self.enabled = True
 self.dropdownWidth = 'W' * 16
 self.width = 'W' * 16
 mxd = arcpy.mapping.MapDocument("CURRENT")
 self.mxd = arcpy.mapping.MapDocument("CURRENT")
 self.df = arcpy.mapping.ListDataFrames(mxd)[0]
 def onSelChange(self, selection):
 layer = arcpy.mapping.ListLayers(self.mxd, "block_cards", self.df)[0]
 a = arcpy.SelectLayerByAttribute_management(layer, "NEW_SELECTION", "town = '{}'".format(selection))
 self.df.extent = layer.getSelectedExtent()
 arcpy.RefreshActiveView()
 def onFocus(self, focused):
 layer = arcpy.mapping.ListLayers(self.mxd, "block_cards", self.df)[0]
 arcpy.SelectLayerByAttribute_management(layer, "CLEAR_SELECTION")
 self.items = sorted(list(set(filter(None, [row[0] for row in arcpy.da.SearchCursor(layer, ["town"])]))))
class ComboBoxClass2(object):
 """Implementation for addin2_addin.combobox (ComboBox)"""
 def __init__(self):
 self.editable = True
 self.enabled = True
 self.dropdownWidth = 'W' * 6
 self.width = 'W' * 6
 mxd = arcpy.mapping.MapDocument("CURRENT")
 self.mxd = arcpy.mapping.MapDocument('current')
 self.df = arcpy.mapping.ListDataFrames(mxd)[0]
 def onSelChange(self, selection):
 layer = arcpy.mapping.ListLayers(self.mxd, "block_cards", self.df)[0]
 arcpy.SelectLayerByAttribute_management(layer, "NEW_SELECTION", "town = '{}' AND LABELTEXT = '{}'".format(combobox.value, selection))
 self.df.extent = layer.getSelectedExtent()
 arcpy.RefreshActiveView()
 def onFocus(self, focused):
 layer = arcpy.mapping.ListLayers(self.mxd, "block_cards", self.df)[0]
 arcpy.SelectLayerByAttribute_management(layer, "CLEAR_SELECTION")
 expression = "town = '{}'".format(combobox.value)
 self.items = sorted(list(set(filter(None, [row[0] for row in arcpy.da.SearchCursor(layer, ["LABELTEXT"], where_clause=expression)]))))

• crmackey: That is pretty cool, I guess I never thought of it that way. As per my post, I have always used buttons to execute the query, but I suppose that wasn't necessary after all. I never thought to build that logic right into the onSelection method. Does this work pretty fast?

Answer 2

To get at the value from your ComboboxClass1 value, you need to look in the config.xml for that class and whatever is after the period is what you need to reference. Since you have more than one combobox I think you would want to make sure these classes have unique names after to period when you set up the Add-In.

EDIT:

That being said, you do not want to excecute tasks from the combobox. Instead, you may want to have the user select values from two comboboxes and then have a button to execute the query. So I would go back to the add in wizard and create a button to run it.

This is how I would do it:

import arcpy
import pythonaddins
class Query(object):
 """Implementation for addin2_addin.button (Button)"""
 def __init__(self):
 self.enabled = True
 self.checked = False
 self.mxd = arcpy.mapping.MapDocument('current')
 self.df = self.mxd.activeDataFrame
 self.layer = arcpy.mapping.ListLayers(self.mxd, "block_cards", self.df)[0]
 def onClick(self):
 # select features
 arcpy.SelectLayerByAttribute_management(self.layer, "NEW_SELECTION", "town = '{}' AND LABELTEXT = '{}'".format(combobox.value, combobox_1.value)) #assuming these are the proper names
 self.df.extent = self.layer.getSelectedExtent() 
 arcpy.RefreshActiveView()
class ComboBoxClass1(object): 
 """Implementation for addin2_addin.combobox (ComboBox)""" 
 def __init__(self): 
 self.editable = True 
 self.enabled = True 
 self.dropdownWidth = 'W' * 16
 self.width = 'W' * 16
 def onSelChange(self, selection):
 mxd = arcpy.mapping.MapDocument('current')
 layer = arcpy.mapping.ListLayers(mxd, "block_cards", df)[0] 
 arcpy.SelectLayerByAttribute_management(layer, "CLEAR_SELECTION")
 self.mxd = arcpy.mapping.MapDocument('current')
 self.df = self.mxd.activeDataFrame
 self.layer = arcpy.mapping.ListLayers(self.mxd, "block_cards", self.df)[0] 
 arcpy.RefreshActiveView()
 def onFocus(self, focused):
 layer = arcpy.mapping.ListLayers(self.mxd, "block_cards", df)[0] 
 self.items = sorted(list(set(filter(None, [row[0] for row in arcpy.da.SearchCursor(layer, ["town"])])))) 
class ComboBoxClass2(object): 
 """Implementation for addin2_addin.combobox (ComboBox)""" 
 def __init__(self): 
 self.editable = True 
 self.enabled = True 
 self.dropdownWidth = 'W' * 6
 self.width = 'W' * 6
 self.mxd = arcpy.mapping.MapDocument('current')
 self.layer = arcpy.mapping.ListLayers(self.mxd, "block_cards", self.df)[0] 
 def onSelChange(self, selection):
 arcpy.SelectLayerByAttribute_management(self.layer, "CLEAR_SELECTION") 
 arcpy.RefreshActiveView()
 def onFocus(self, focused): 
 self.items = sorted(list(set(filter(None, [row[0] for row in arcpy.da.SearchCursor(self.layer, ["LABELTEXT"])])))) 

You can find the combobox class names in the config.xml like this Add-In I have built in the past:

enter image description here

Here is an example of an Add-In I created in the past that finds unconnected features and uses 2 comboboxes. May not be perfect, but shows an example of using 2 comboboxes and a button:

import arcpy
import pythonaddins
class Query(object):
 """Implementation for FindUnconnectedFeatures_addin.button (Button)"""
 def __init__(self):
 self.enabled = True
 self.checked = False
 def onClick(self):
 mxd = arcpy.mapping.MapDocument('Current')
 df = mxd.activeDataFrame
 targ = arcpy.mapping.ListLayers(mxd, combobox.value)[0]
 source = arcpy.mapping.ListLayers(mxd, combobox_1.value)[0]
 sel = 'INTERSECT'
 # select by location
 arcpy.SelectLayerByLocation_management(targ, sel, source)
 arcpy.SelectLayerByAttribute_management(targ, 'SWITCH_SELECTION')
class SourceLayer(object):
 """Implementation for FindUnconnectedFeatures_addin.combobox_1 (ComboBox)"""
 def __init__(self):
 self.items = []
 self.editable = True
 self.enabled = True
 self.dropdownWidth = 'W' * 12
 self.width = 'W' * 12
 def onSelChange(self, selection):
 pass
 def onEditChange(self, text):
 pass
 def onFocus(self, focused):
 if focused:
 self.mxd = arcpy.mapping.MapDocument('current')
 self.df = self.mxd.activeDataFrame
 lyrs = [l.name for l in arcpy.mapping.ListLayers(self.mxd, '*', self.df)
 if not l.isBroken and l.supports('DATASOURCE')]
 self.items = sorted(lyrs)
 del self.mxd
 def onEnter(self):
 pass
 def refresh(self):
 pass
class TargLayer(object):
 """Implementation for FindUnconnectedFeatures_addin.combobox (ComboBox)"""
 def __init__(self):
 self.items = []
 self.editable = True
 self.enabled = True
 self.dropdownWidth = 'W' * 12
 self.width = 'W' * 12
 def onSelChange(self, selection):
 pass
 def onEditChange(self, text):
 pass
 def onFocus(self, focused):
 if focused:
 self.mxd = arcpy.mapping.MapDocument('current')
 self.df = self.mxd.activeDataFrame
 lyrs = [l.name for l in arcpy.mapping.ListLayers(self.mxd, '*', self.df)
 if not l.isBroken and l.supports('DATASOURCE')]
 self.items = sorted(lyrs)
 del self.mxd
 def onEnter(self):
 pass
 def refresh(self):
 pass