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This element allows you to define variables for the variables substitution system. Some variables are built-in, such as $INSTALL_PATH (which is the installation path chosen by the user). When you

To define a set of variables, you just have to place as many <variable> tags in the file as needed. elements as needed inside a <variables> or <dynamicvariables> element which are in turn children of the <installation> element.

If you define a variable named VERSION you need to type $VERSION in the files to parse. The variable substitutor will then replace it with the correct value. One

Each <variable> tag take the following attributes :

  • name : the variable name
  • value : the variable value

Here's a sample <variables> section :


Code Block
  <variable name="app-version" value="1.4"/>
  <variable name="released-on" value="08/03/2002"/>

Types of Variables


Static variables can be defined by the user using the <variables> tag in the installation description element.
They are evaluated on launching an installation and won't alter during the installation process. Static variables can assigned from an system environment variable on launching an IzPack installations.


Dynamic variables can be defined by the user using the <dynamicvariables> tag element in the installation description.
Dynamic variables are the most powerful facility of saving and gathering values on a target system where the installation is launched. The value of dynamic variables will be evaluated every time a panel is switched. Furthermore, beginning with IzPack 5.0, dynamic variables can be also assigned from several configuration and archive files, the Windows registry, the output of a command execution and dynamically filtered using Java regular expressions. See Dynamic Variables for more information and some examples how this can be achieved.
Dynamic variables can be handled like other variable types for variable substitution.