Ant Actions Listeners - AntActionInstallerListener/AntActionUninstallerListener

In this section the common ant task custom actions are described in detail. It is only for developers who are not acquainted with IzPack or it's custom actions. In addition to the basics there are some recapitulations of the common custom action techniques and some hints for pitfalls. In the package com.izforge.izpack.event there are the ant related custom actions AntActionInstallerListener and AntActionUninstallerListener. As recapitulation, to add any custom action a reference in install.xml will be needed, as example:

<listeners>
    <listener installer="AntActionInstallerListener"
        uninstaller="AntActionUninstallerListener" />
</listeners>

For all referenced listeners a jar file with the same name must exist in IzPackRoot/bin/customActions. If compilation (packaging) fails with a "not found" error, first verify, that the jar file exists. If not, create it. With this custom action it is possible to perform ant calls at installation and/or uninstallation time. It is not only a wrapper for a comand-line ant call, but also an intersected description file defining what target of the ant build file should be performed at what time of (un)installation and specifies which properties for what IzPack pack are to be used. The intersected description file is written as XML, the corresponding dtd is placed in src/dtd/event/antaction.dtd. The description file should be declared as a resource in the install.xml with the id AntActionsSpec.xml e.g.

<resources>
    ...
    <res id="AntActionsSpec.xml"
    src="myInstallSpecs/MyAntActionsSpec.xml" />
    ...
</resources>

The precise spelling of the id is important. The base path of src is the installation project path. If you want to use ant, you have to specify it here. IzPack is designed for running without dependencies on external software or libraries. Therefore it is necessary to include everything needed, in this case ant self. The field <jar> in installation.xml is predestinated for such cases, e.g.

<jar src="jar/ant/ant.jar" stage="both" />

Be aware, that an "extended" ant use needs more than one jar, for example often xercesImpl.jar. If an obscure "class not found" exception is raised during testing, check first for missing jar files. For supporting uninstallation the jar field was extended by the attribute stage. If an ant uninstaller custom action is used, the uninstaller also needs the jar files. If stage is "both" or "uninstall", the contents of the referenced jar file will be packed into uninstaller.jar. Be aware that not the jar file itself, but the contents of it are required. This implies, that the paths of the contained files are unique and the information in meta-inf/Manifest.mf will be lost.

The AntActionSpec XML Struture

An ant action will be defined in the resource with the id "AntActionsSpec.xml". Sometimes it will help to look into createpage.action?spaceKey=IZPACK&title=IzPackRoot&linkCreation=true&fromPageId=142803064antaction.dtd (4.x SVN trunk) or validate a written xml file with the dtd.

Prior to processing the packs a substitution is performed using all defined IzPack variables on the spec file. This is a common way of loading spec files into custom actions. For more information see method com.izforge.izpack.util.SpecHelper.readSpec. If you want to substitute a value in the file, simply add a variable via idata.setVariable in a custom panel before InstallPanel. The given variable name (id) should be written into the xml file in the common variable notation.

The following outlines the sections available in the AntActionsSpec.xml:

antactions

The top level XML section is called <antactions>. The antactions element may contain zero or more pack elements described below:

pack

The pack element is used to tie the action(s) to be performed to the packs selected in the installation. The pack element may have the following attribute:

The pack element must contain 1 or more antcall elements.

antcall

The antcall element has the following attributes:

In addition to the possible attributes there are some elements may be defined within an antcall element. All elements can be defined zero or more times in an <antcall>. Although all elements are optional, no ANT tasks will be performed unless a <target> element is specified. Do not confuse the following: "required"s are related to the attributes of the elements, not to the elements themselfs.

property

Defines a property to be used with all targets and uninstall_targets which are defined for this antcall.  The following attributes may be defined:

propertyfile

Defines properties to be used, read from a property file which are defined for this antcall.  The following attributes may be defined:

One way to fill specific data into it is to create a new file in a custom panel and fill it with values given by input fields. The file path can be set at installation time, if there is a variable in AntActionSpec.xml and an IzPack variable was defined before InstallPanel. That file can be only created with deleteOnExit, if no <uninstall_target> was defined in this <antcall>. This implies, that other <antcall>}}s can have a {{<uninstall_target>. <target>: target to call at installation h3. Targets to perform with this antcall at installation time. The targets should be defined in the given buildfile or else an ant exception will be raised. This is that what you use, if you don't want to perform the default target. e.g. cleaning the IzPack project with ant clean.

target

The target to execute in the ANT build file during action specified in the order attribute of the antcall (install time).  Note: Multiple targets to execute for the action may be specified by using multiple target elements.  The following attribute must be defined:

uninstall_target

Targets to perform with this antcall at uninstallation time. Note: Multiple targets to execute for the action may be specified by using multiple target elements.