Since Ant 1.8.0
This task is provided for the purpose of allowing the user to (a) install a
different PropertyHelper at run time, or (b) (hopefully more often)
install one or more PropertyHelper Delegates into
the PropertyHelper active on the
current Project. This is somewhat advanced Apache Ant usage and assumes a
working familiarity with the modern Ant APIs. See the description of
Ant's Property Helper for more information.
You may specify exactly one configured org.apache.tools.ant.PropertyHelper
instance.
You may specify, either in conjunction with a new PropertyHelper or
not, one or more configured implementations of
the org.apache.tools.ant.PropertyHelper.Delegate interface. A deeper
understanding of the API is required here, however, as Delegate is a
marker interface only: the nested arguments must implement a Delegate
subinterface in order to do anything meaningful.
A generic <delegate> element which can use project references is also
provided:
| Attribute | Description | Required |
|---|---|---|
| refid | The id of a PropertyHelper.Delegate to install. |
Yes |
Install a completely different PropertyHelper implementation
(assuming MyPropertyHelper extends PropertyHelper):
<componentdef classname="org.example.MyPropertyHelper"
name="mypropertyhelper"/>
<propertyhelper>
<mypropertyhelper/>
</propertyhelper>
Add a new PropertyEvaluator delegate
(assuming MyPropertyEvaluator implements
PropertyHelper.PropertyEvaluator). Note that PropertyHelper uses
the configured delegates in LIFO order. I.e. the delegate added by this task will be consulted
before any previously defined delegate and in particular before the built-in ones.
<componentdef classname="org.example.MyPropertyEvaluator"
name="mypropertyevaluator"/>
<propertyhelper>
<mypropertyevaluator/>
</propertyhelper>
Add a new PropertyEvaluator delegate using the refid
syntax:
<typedef classname="org.example.MyPropertyEvaluator"
name="mypropertyevaluator"/>
<mypropertyevaluator id="evaluator"/>
<propertyhelper>
<delegate refid="evaluator"/>
</propertyhelper>