Hi,

I'm putting my own tool into Galaxy. Suppose I have an command line option that is designated by a switch. Such as

$executable.py -a option input output

The "-a option" is an optional argument. I want to make sure when the option is not given, "-a option" is entirely taken out.

I tried Cheetah script like this (this fails):

<command interpreter="python">executable #if $option != None
                                                 -a $option
                                                 #end if
                                                 $input $output</command>

This $option is suppose to be an optional tabular file and is written within <param> as:
<param name="option" type="data" format="tabular" label="XXX" optional="true"/>

Somehow "-a None" is always printed (as seen from the server print-to-screen). But I thought I checked explicitly for it to be anything but None.

Then I realized that type($option) <class 'galaxy.tools.DatasetFilenameWrapper'>. So I coerced both that and NoneType into string prior to checking for equality. Is this the proper way to do it?

Timothy