Configuration Options

Configuration Options

Autoproj supports adding user decision in the installation process of a software system. They can be used to local customization of the installation on a users PC. For example they can be used to let the user decide whether he requires a certain feature or not, or which particular implementation of a selection of possible choices for a technology he wants to use.

User Interaction

During the processing of aup or autoproj update, the user will be prompted to select a value for Configuration Options, for which no choice has been made so far. To change assignments of Configuration Options, run the following command autoproj reconfigure.

The user promt will look like shown on this screenshot:

Defining Configuration Option

The place for defining Configuration Options are the init.rb or .autobuild files of a Package Set. Here's an example.

Definition of a Configuration Option
The following snipped defines a string Configuration Option with a set of allowed values:

# In file libs.autobuild of a package set
# An example using an String option
Autoproj.configuration_option('MY_USER_OPTION', 'string',
    :default => 'first_option',
    :possible_values => ['first_option', 'another_option', 'third_option'],
    :doc => [
        "Choose your option wisely ?",
        "Above text is the question which will be asked to t user during configuring your installation.", "Explain more elaborately what this option means", "you can split your text in multiple lines", "by splitting the text into separate strings per line."])

The following snipped defines a boolean Configuration Option:

# In file libs.autobuild of a package set
# An example using a bool option
Autoproj.configuration_option "ENABLE_FEATURE_A", "boolean",
   	:doc => ["Enable feature A ?",
   	   	"Feature is very good. It's the best feature!",
   	        "You should really consider enabling it."],
   	:default => 'yes'

Evaluating the selection
In this example the user choice of a Configuration Option is evaluated to customize the compilation of a software package.

# In file libs.autobuild of a package set
cmake_package 'some_package' do |pkg|
    if Autoproj.config.get("ENABLE_FEATURE_A")
        pkg.define("SOME_COMPILER_OPTION", "On")
        pkg.depends_on('some_additional_package')
        Autoproj.info "Building 'some_package' with FEATURE_A!"
    else
        Autoproj.info "Building 'some_package' without FEATURE_A!"
    end     
end

This example defines a package only if a special feature is enabled:

if Autoproj.config.get("ENABLE_FEATURE_A")
    cmake_package 'some_package'
end