I am creating a macrodef that calls <exec>. I want to make it possible to
parameterize the "error" attribute by doing something like:
<macrodef name="closure-compile-with-error">
<attribute name="outputfile" />
<attribute name="compilationlevel" default="SIMPLE_OPTIMIZATIONS" />
<attribute name="outputmode" default="compiled" />
<attribute name="failonerror" default="true" />
<attribute name="error" default="" />
<element name="extraflags" optional="yes" />
<element name="extrapaths" optional="yes" />
<sequential>
<exec executable="python"
failonerror="@{failonerror}"
error="@{error}"
logError="true">
<arg value="${calcdeps.py}" />
<arg line='--output_file="@{outputfile}"' />
<extrapaths />
<arg line='-p "${closure-library.dir}"' />
<arg line="-o @{outputmode}" />
<arg line='-c "${closure-compiler.jar}"' />
<arg line='-f "--compilation_lev...@{compilationlevel}"' />
<extraflags />
</exec>
</sequential>
</macrodef>
The problem is that by defining an optional attribute:
<attribute name="error" default="" />
I have to give it a default value, which in this case becomes empty string.
If the caller of <closure-compiler-with-error> does not want to specify
"error", then <exec> ends up trying to write stderr to the current
directory, which fails because it is a directory and not a file. Ideally,
the default value would be "/dev/null" or something like that, but I also
want this to work on Windows.
It seems that this is a more general problem where I only want to include
certain options if they are specified. As you can see, I created
<extraflags> and <extrapaths> to handle that problem in general, but I do
not believe I can do something similar for <exec>, can I?
Thank you,
Michael
