Re: Using "if" to test for existence of properties

I think I have run into this before. I think the easiest fix is to make sure the property always exists. Then you can check to see if it is not empty.

BOb


From: Durand Van Arnem [mailto:[email protected]]
Sent: Tuesday, April 13, 2010 10:33 AM
To: NAnt Users
Subject: [NAnt-users] Using "if" to test for existence of properties

Hello,

I could use some advice about how to handle this situation:

I have a property, MyProperty, that may or may not be set.  I want a task to execute if the property is set, e.g.
<echo messsage="Hello ${MyProperty}!" if="${property::exists('MyProperty')" />

If MyProperty is not set, this task fails because NAnt appears to evaluate the message portion regardless of the result of the IF evaluation.  I could rewrite like this:

<if test="${property::exists('MyProperty')}">
    <echo message="Hello ${MyProperty}!" />
</if>

However, I run into the same issue with filterchains:

<!-- FAILS if MyProperty is not set, because NAnt evaluates the tokens regardless of the IF result -->
<copy failonerror="true" verbose="true" todir="C:\Temp">
    <fileset refid="Deploy-FileSet" />
    <filterchain>
        <replacetokens begintoken="[" endtoken="]" ignorecase="true" if="${property::exists('MyProperty')}">
            <token key="ABC" value="${MyProperty}" />
        </replacetokens>
    </filterchain>
</copy>

I'd rather not enclose the whole definition of the copy in an IF, with a nearly identical "else" version for the case when MyProperty is not set.

How have you handled this situation?

Thanks,
Durand

------------------------------------------------------------------------------
Download Intel&#174; Parallel Studio Eval
Try the new software tools for yourself. Speed compiling, find bugs
proactively, and fine-tune applications for parallel performance.
See why Intel Parallel Studio got high marks during beta.
http://p.sf.net/sfu/intel-sw-dev

_______________________________________________
NAnt-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/nant-users