ToolValidator not doing anything

Question

I have created a simple script tool which has a single parameter of type "String". I have written the tool validation to disable the input field (simply trying to learn tool validation). The validator code is as follows:

class ToolValidator:

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

  def initializeParameters(self):
    self.params[0].Enabled = 0
    return

  def updateParameters(self):
    return

  def updateMessages(self):
    return

Unfortunately, when I open the tool, the field is not disabled (as I expect it should be). Any ideas what I'm missing?

SOLUTION: In case it's not clear in the threads below. The solution to the issue was to change Enabled to enabled, which is a case change between ArcGIS 9.3 and 10.0. This capitalization works correctly both in the initializeParameters method and the updateMessages method.

Answer 1

I think you are putting it in the wrong spot. This is how I've done it previously.

def updateMessages(self):
    self.params[0].enabled = False

Answer 2

I was able to get it running by using enabled instead of Enabled.

Here is a link that lists all of the available params properties (they show lowerCamelCase for all of the properties): Programming a ToolValidator class