YaST2 Proposal API

After five releases, YaST2 is now smart enough to make reasonable proposals for (near) every installation setting, thus it is no longer necessary to ask the user that many questions during installation: Most users simply hit the [next] button anyway.

Hence, YaST2 now collects all the individual proposals from its submodules and presents them for confirmation right away. The user can change each individual setting, but he is no longer required to go through all the steps just to change some simple things. The only that (currently) really has to be queried is the installation language - this cannot reasonably be guessed (yet?).

The new YaST2 installation includes the following steps:

After this, all that is remained left is basic system configuration like:

YaST2 installation modules should cooperate with the main program in a consistent API. General usage:

Each submodule provides a function dispatcher that can be called with 'CallFunction()'. The function to be called is passed as a parameter to this dispatcher. Parameters to the function are passed as another parameter in a map. The result of each call is a map, the contents of which depend on the function called.

The reason for this additional overhead is to provide extensibility and reusability for the installation workflow: A list of submodules to be called is read from file. This requires, however, that no explicit 'mod::func()' calls are used in 'inst_proposal.ycp'. Rather, the list contains the name of the submodule. Since each submodule is required to provide an identical API, this is sufficient.

	map result = CallFunction (input_devices( "MakeProposal", $[ "force_reset"     : false,
	"language_changed": false ] ) );
	map result = CallFunction (partitioning ( "MakeProposal", $[ "force_reset"	  : false,
	"language_changed": false ] ) );
	...

      

	
	map result = CallFunction (input_devices( "AskUser", $[ "has_next": true ] ) );
      

	Note
	If any parameter is marked as "optional", it should only be specified if it contains a meaningful value. Don't add it with a 'nil' value.

The dispatcher provides the following functions:

      # encoding: utf-8

# Module:		proposal_dummy.ycp
#
# $Id$
#
# Author:		Stefan Hundhammer <sh@suse.de>
#
# Purpose:		Proposal function dispatcher - dummy version.
#			Use this as a template for other proposal dispatchers.
#			Don't forget to replace all fixed values with real values!
#
#			See also file proposal-API.txt for details.
module Yast
  class DummyProposalClient < Client
    def main
      textdomain "installation"

      @func = Convert.to_string(WFM.Args(0))
      @param = Convert.to_map(WFM.Args(1))
      @ret = {}

      if @func == "MakeProposal"
        @force_reset = Ops.get_boolean(@param, "force_reset", false)
        @language_changed = Ops.get_boolean(@param, "language_changed", false)

        # call some function that makes a proposal here:
        #
        # DummyMod::MakeProposal( force_reset );

        # Fill return map

        @ret = {
          "raw_proposal"  => [
            "proposal item #1",
            "proposal item #2",
            "proposal item #3"
          ],
          "warning"       => "This is just a dummy proposal!",
          "warning_level" => :blocker
        }
      elsif @func == "AskUser"
        @has_next = Ops.get_boolean(@param, "has_next", false)

        # call some function that displays a user dialog
        # or a sequence of dialogs here:
        #
        # sequence = DummyMod::AskUser( has_next );


        # Fill return map

        @ret = { "workflow_sequence" => :next }
      elsif @func == "Description"
        # Fill return map.
        #
        # Static values do just nicely here, no need to call a function.

        @ret = {
          # this is a heading
          "rich_text_title" => _("Dummy"),
          # this is a menu entry
          "menu_title"      => _("&Dummy"),
          "id"              => "dummy_stuff"
        }
      elsif @func == "Write"
        # Fill return map.
        #

        @ret = { "success" => true }
      end

      deep_copy(@ret)
    end
  end
end

Yast::DummyProposalClient.new.main