ArcPy - Add Layer from Cursor Selection

Question

I am trying to add layers from the fields of a reference layer using select by location and a cursor. Also, want to prompt the user with a message box asking if they want to add the selected by location. I am able to print string value from the reference layer when the user responds with "Yes" with the message box, but get an error when passing the string value as a path using "arcpy.mapping.addLayer".

def onMouseDownMap(self, x, y, button, shift): 
 mxd = arcpy.mapping.MapDocument("CURRENT")
 df = arcpy.mapping.ListDataFrames(mxd,"*")[0]
 #layer path
 lyr1 = arcpy.mapping.Layer("C:\ArcGis\Aerial_Imagery.lyr")
 #Add Layer
 arcpy.mapping.AddLayer(df, lyr1, "TOP")
 point = arcpy.Point(x, y)
 ptGeometry = arcpy.PointGeometry(point)
 #Select layer by points/mouse down on map
 arcpy.SelectLayerByLocation_management("Aerial_Imagery.lyr", "INTERSECT", ptGeometry)
 #cursor to display selected layers on field name "Layer_Path"
 cursor = arcpy.SearchCursor("Aerial_Imagery.lyr")
 field = "Layer_Path"
 for row in cursor:
 selpath = (row.getValue(field))
 message = "Would you like to add this Imagery:" + selpath
 Addbutton = pythonaddins.MessageBox(message, "Imagery Finder", 4)
 if Addbutton == "Yes":
 addlyr = arcpy.mapping.Layer(selpath)
 arcpy.mapping.AddLayer(df, addlyr, "TOP")#this breaks
 print selpath #this works
 else:
 pythonaddins.MessageBox("this is the answer to NO", "no answer", 0)
 #Remove Layer
 for lyr in arcpy.mapping.ListLayers(mxd, "Aerial_Imagery.lyr"):
 #print "Remove Layer", lyr
 arcpy.mapping.RemoveLayer(df, lyr)
 #Refresh view and TOC
 arcpy.RefreshActiveView()
 arcpy.RefreshTOC()

• whuber: Please tell us exactly what the error message says.

Answer 1

Code looks OK to me so I guess its down to formatting of the string especially with "\" or "/" or "\\" .

This line:

lyr1 = arcpy.mapping.Layer("C:\ArcGis\Aerial_Imagery.lyr")

should really be:

lyr1 = arcpy.mapping.Layer(r"C:\ArcGis\Aerial_Imagery.lyr")

or it could be:

lyr1 = arcpy.mapping.Layer("C:\\ArcGis\\Aerial_Imagery.lyr")

So the full path that you are extracting out of image catalog layer should be formatted correctly. A simple find and replace of "\" with "\\" will work.