topic Re: Setting multivalue parameters to True in Python Questions

Setting multivalue parameters to True

JonPedder — Thu, 14 Mar 2013 23:18:23 GMT

Hi all, is there a way to set the default values in a multivalue Parameter to True or Selected?

Thanks

Re: Setting multivalue parameters to True

MelanieMaguire — Sat, 16 Mar 2013 01:26:55 GMT

Is your multi-value parameter for a script tool or an add-in component? Can you show the outline for the code where you would like to implement this?

Re: Setting multivalue parameters to True

JonPedder — Sat, 16 Mar 2013 19:58:10 GMT

It's for a script tool. I'm using a string parameter with a value list. Right now the value list is generated in teh script tool but could be created using validation class I guess?

I have 6 string values that I'd like to set by default to True or Checked. So when the script tool is opened the multivalue string check boxes are selected.

I'm not stuck on string as a type, I could easily select another data type and work with that. Using individual Boolean parameters makes the script tool extend too far (too much screen space), unless there's a way to arrange Boolean within the script tool?

Thanks

Jon

Re: Setting multivalue parameters to True

T__WayneWhitley — Sat, 16 Mar 2013 20:32:55 GMT

I did just this for a tool last week - I'm at 10.0 and used the ToolValidator, simple changing (or adding) 3 lines:

class ToolValidator:   """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."""     import arcpy     self.params = arcpy.GetParameterInfo()     def initializeParameters(self):     """Refine the properties of a tool's parameters.  This method is     called when the tool is opened."""     self.params[0].filter.list = ['val1', 'val2', 'val3', 'val4']     return     def updateParameters(self):     """Modify the values and properties of parameters before internal     validation is performed.  This method is called whenever a parmater     has been changed."""      if not self.params[0].altered:       self.params[0].value = r"'val1';'val2';'val3'"     return     def updateMessages(self):     """Modify the messages created by internal validation for each tool     parameter.  This method is called after internal validation."""     return

The line "self.params[0].filter.list = ['val1', 'val2', 'val3', 'val4']" sets my value list (in this case, for the 1st input parameter ([0]), a multivalue param.

The 2-line block sets up the default 3 vals checked on by default - if what is checkmarked by default is 'altered', then that defines the new input:

if not self.params[0].altered:       self.params[0].value = r"'val1';'val2';'val3'"

As a result, on execution vals 1-3 are on and are fetched correctly at GetParameterAsText and if val4 is checked on, then GetParameterAsText fetches the additional val4. (or if any other combination is chosen, the input is adjusted accordingly) Perfect!

Enjoy,
Wayne

Re: Setting multivalue parameters to True

JonPedder — Sun, 17 Mar 2013 15:47:58 GMT

Perfect, thanks very much Wayne!