ToolValidator para Agregar campo

Este ejemplo simula la validación de la herramienta Agregar campo. Dado que Agregar campo es una herramienta del sistema, no tiene una clase ToolValidator. Pero si la tuviera, sería algo parecido a esto.

A modo de revisión, a continuación presentamos los parámetros para Agregar campo y sus tipos de datos:

• 0 - Tabla de entrada: tipo de datos compuesto, incluye todas las tablas
• 1 - Nombre del campo: Cadena de caracteres
• 2 - Tipo del campo: cadena de texto (LONG, SHORT, DOUBLE y así sucesivamente)
• 3 - Precisión del campo: largo
• 4 - Escala del campo: largo
• 5 - Longitud del campo: largo
• 6 - Alias del campo: Cadena de caracteres
• 7 - Permitir campos nulos: Booleano
• 8 - Campo necesario en la tabla: Booleano
• 9 - Dominio del campo: Cadena de caracteres
• 0 - Tabla de salida: salida derivada, obtenida del parámetro 0

Este ejemplo simula la validación de la herramienta Agregar campo

 class ToolValidator:      def __init__(self):         import arcpy          self.params = arcpy.GetParameterInfo()      def initializeParameters(self):         # The derived output is a clone (copy) of the input         #         self.params[10].parameterDependencies = [0]         self.params[10].schema.clone = True          # Set up the field type list         #         self.params[2].filter.list = ["TEXT", "FLOAT", "DOUBLE",                                       "SHORT", "LONG", "DATE",                                       "BLOB", "RASTER"]          # The default field type is LONG         #         self.params[2].value = "LONG"          # Field scale & Length are disabled for LONG types         #         self.params[4].enabled = False         self.params[5].enabled = False          # Set the Boolean filters for IsNullable and IsRequired and         #  their default values         #         self.params[7].filter.list = ["NULLABLE", "NON_NULLABLE"]         self.params[7].value = "NULLABLE"                  self.params[8].filter.list = ["REQUIRED", "NON_REQUIRED"]         self.params[8].value = "NON_REQUIRED"          return      def updateParameters(self):         # Set the default field type value unless the user altered it         #         if not self.params[2].altered:             self.params[2].value = "LONG"          # Enable/Disable parameters based on field type         #         fieldType = self.params[2].value.upper()         if fieldType in ["TEXT", "BLOB"]:             self.params[3].enabled = False             self.params[4].enabled = False             self.params[5].enabled = True         elif fieldType in ["FLOAT", "DOUBLE"]:             self.params[3].enabled = True             self.params[4].enabled = True             self.params[5].enabled = False         elif fieldType in ["SHORT", "LONG"]:             self.params[3].enabled = True             self.params[4].enabled = False             self.params[5].enabled = False         elif fieldType in ["DATE", "RASTER"]:             self.params[3].enabled = False             self.params[4].enabled = False             self.params[5].enabled = False         else:             # Unknown field type.  Internal validation will catch this             #  and show an error. We might as well return here and let             #  internal validation do its work.             #             return                  # Update the output schema with the new field. Don't do anything         #  unless we have an input value and a field name         #         if self.params[0].value and self.params[1].value:             newField = arcpy.Field()             newField.name = self.params[1].value             newField.type = self.params[2].value              # Set up the field properties based on type of field             #             if self.params[3].value and self.params[3].enabled:                 newField.precision = self.params[3].value             if self.params[4].value and self.params[4].enabled:                 newField.scale = self.params[4].value             if self.params[5].value and self.params[5].enabled:                 newField.length = self.params[5].value                              if self.params[6].value:                 newField.aliasName = self.params[6].value                              newField.isNullable = self.params[7].value              # Note: IsRequired is not a property on a field object -- it's             #  handled internally by the Add Field system tool.             #              if self.params[9].value:                 newField.domain = self.params[9].value              # Set the additional field on the output schema             #             self.params[10].schema.additionalFields = [newField]      def updateMessages(self):         return