My vote for a "language" within if/unless elements is to use XPath (1 or 2). Pretty powerful and standard within the XML domain! You could even think of supporting path expressions that access the entities (targets, properties, types etc.) within the current Ant build file and could provide some supporting functions that allow tasks and/or targets (in the current build) to be invoked or other ant-specific operations to be performed.
I am not sure. I disagree because the standards group that I am involved in as a day job has been proposing using xpath for its reference model within an XML deployment descriptor (https://forge.gridforum.org/projects/cddlm-wg/), and I have concluded it doesnt work once
you have a more complex model.
The problem is that xpath paths refers to document structure and not to object structure. Now that we have an interitance model (<import>),the two are not the same. So if you are trying to refer to targets, xpath may be wrong. Here, for example:
<target name="foo" depends="/[EMAIL PROTECTED]'init']">
To maintain backwards compatibility, all that is needed is a delimiter that indicates that an XPath expression is being used. E.g.
... if="debugmode" ...
for backwards compatibility or
... if="@call("available", "file", ${file}) == true()" ...
to indicate that the "available" task should be called with the specified property set as the "file" attribute (XPath supports "varargs" so having name/value pairs of parameters to define the attributes of the invoked task is easy to implement). Explicit functions could be made available for the most common task invocations in conditions.
At the same time, we dont want a condition language that is home rolled, do we. Which is a strong argument in favour of Xpath, build file structure notwithstanding.
Finally, it would even be possible to drop the delimiter and evaluate the expression as an XPath instead of as a property name if there are any "illegal" property name characters (such as "(", "/" or whitespace) in the expression.
Not even whitespace is forbidden. typeof(property)!=xsd:NCName :)
<property name="(/) !" value="naughty!" />
<echo >${(/) !}</echo>result:
[echo] naughty!-steve
--------------------------------------------------------------------- To unsubscribe, e-mail: [EMAIL PROTECTED] For additional commands, e-mail: [EMAIL PROTECTED]
