Wannheden, Knut wrote:
I know this topic has been brought up before (e.g. in "Optional tasks" thread of last december [1]), but I still wonder what is the actual plan for the accepted requirement for Ant2.
At one point it was argued that using namespaces would yield to verbose buildfiles. But this all depends on what the namespaces would be used for. In [1] it was suggested that there should be a defined namespace for Ant (including <project>, <target>, core and optional tasks and datatypes) and external tasks and datatypes would have to be declared in a separate namespace. With a namespace enabled <taskdef> a buildfile could look something like this:
<project xmlns="http://jakarta.apache.org/Ant/v2"; xmlns:my="urn:my-ant-tasks" default="test">
<taskdef qname="my:foo" classname="org.bar.FooTask"/> <taskdef name="baz" ns="urn:my-ant-tasks" classname="org.bar.BazTask"/>
<target name="test"> <echo message="test"/> <my:foo/> <whatever:baz xmlns:whatever="urn:my-ant-tasks"/> </target>
</project>
(Note the two different uses of <taskdef>.)
There is a "namespace" feature working on properties in /proposal/embed, and also a SAX2 ProjectHelper.
What needs to be still defined is just how to use namespaces; good you brought the point to the attention :-)
So for all those people not using custom tasks and datatypes the only difference would be the default namespace declaration (or a prefixed one if preferred).
I was just thinking that if there were a namespace for all core Ant XML elements it shouldn't be very hard to write up a RELAX NG grammar to validate buildfiles, even with custom tasks and datatypes in it. And the gain of that in turn is probably quite obvious (although the RNG grammar would require maintainance): - the task implementation would be guarded against wrong usage (validation) - the user wouldn't be surprised by different behaviour of tasks with just swapped attribute order - and maybe a consistent documentation could be generated out of an annotated grammar
Are namespaces intended for this kind of purpose in Ant2?
Can be, I'm personally still musing about the best purpose.
[1] http://www.mail-archive.com/[EMAIL PROTECTED]/msg10233.html
the same afromentioned proposal code has support for overriding the lib dir of Ant; an antlib support (ie automatic taskdefs) is planned, making use of Commons discovery.
In this case, the namespace would be applied to the tasks, so that taskdeffing a jar will yield the tasks with the specified namespace, to prevent clashing.
Also, we could define a namespace to be used for every "import", so that targets imported there do not have problems with name clashes. (see the embed proposal for this tag)
Is this what you advocate?
Other ideas?
--
Nicola Ken Barozzi [EMAIL PROTECTED]
- verba volant, scripta manent -
(discussions get forgotten, just code remains)
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