Quick Navigator

Search Site

Unix VPS
A - Starter
B - Basic
C - Preferred
D - Commercial
MPS - Dedicated
Previous VPSs
* Sign Up! *

Contact Us
Online Help
Domain Status
Man Pages

Virtual Servers

Topology Map

Server Agreement
Year 2038

USA Flag



Man Pages

Manual Reference Pages  -  CONFIG::MODEL::SEARCHELEMENT (3)

.ds Aq ’


Config::Model::SearchElement - Search an element in a configuration model



version 2.082


 use Config::Model;

 # define configuration tree object
 my $model = Config::Model->new;
    name    => "Foo",
    element => [
        [qw/foo bar/] => {
            type       => leaf,
            value_type => string
 $model ->create_config_class (
    name => "MyClass",

    element => [

        [qw/foo bar/] => {
            type       => leaf,
            value_type => string
        hash_of_nodes => {
            type       => hash,     # hash id
            index_type => string,
            cargo      => {
                type              => node,
                config_class_name => Foo
 ) ;

 my $inst = $model->instance(root_class_name => MyClass );

 my $root = $inst->config_root ;

 # put data
 my $step = foo=FOO hash_of_nodes:fr foo=bonjour -
   hash_of_nodes:en foo=hello ;
 $root->load( step => $step );

 # create searcher for manual search
 my $searcher = $root->searcher();

 # looking for foo element in the tree
 $searcher -> prepare (element => foo) ;
 my @next = $searcher->next_step() ;

 print "next possible steps: @next\n";
 # next possible steps: foo hash_of_nodes

 # Looking for foo below hash_of_nodes
 $searcher->choose(hash_of_nodes) ;
 @next = $searcher->next_step() ;

 print "next possible steps: @next\n";
 # next possible steps: en fr

 # Looking for foo below fr
 $searcher->choose(fr) ;
 @next = $searcher->next_step() ;

 print "next possible steps: @next\n";
 # next possible steps: foo

 # last step
 $searcher->choose(foo) ;
 my $target = $searcher->current_object;

 print "Found ",$target->location,"\n";
 # Found hash_of_nodes:fr foo

 # automatic search setup
 my $element_call_back = sub { return hash_of_nodes ;} ;
 my $id_call_back      = sub { return en ;} ;

 $searcher->reset ;
 $target = $searcher->auto_choose($element_call_back, $id_call_back) ;
  print "Automatic search found ",$target->location,"\n";
 # Automatic search found hash_of_nodes:en foo


This modules provides a way to search for a configuration element in a configuration tree by exploring the configuration model.

For instance, suppose that you have a xorg.conf model and you know that you need to tune the MergedXinerama parameter, but you don’t remember where is this parameter in the configuration tree. This module will guide you through the tree to the(s) node(s) that contain this parameter.

This class should be invaluable to construct interactive user interfaces.

This module provides 2 search modes:
o A manual search where you are guided step by step to the element you’re looking for. At each step, the module will return you the possible paths to choose from. The user will have to choose the correct path from the available paths. Most of the time, only one possibility will be returned, so the user choice should be straightforward. In other case (more that one choice), the user will have to decide the next step.
o An automatic search where you provide call-back that will resolve the ambiguities in case of multiple paths.


The constructor should be used only by Config::Model::Node.



Return the list of elements found in model that can be searched in the configuration tree.

    prepare(element => ...)

Prepare the searcher to look for the element passed in the argument. Returns the searcher object (i.e. $self).


Re-initialize the search engine to redo the search from start


Returns the searched element name.

Manual search


Returns an array (or a ref depending on context) containing the next possible step to find the element you’re looking for. The array ref can contain 1 or more elements.

If the array ref is empty, you can get the target element with current_object().


Returns an array ref containing the next non-obvious choice to find the element you’re looking for.

If the array ref is empty, you can get the target element with current_object().

    choose( <chosen_element_name> )

Tell the search engine your choice. The chosen element name must be one of the possibilities given by next_step().


Returns the object where the search engine is. It can be a node, a list, a hash, or a leaf element.

Automatic search

    auto_choose ( element_callback, id_call_back)

Finds the searched element with minimal user interaction.

element_callback will be called when the search engine finds a node where more than one element can lead to the searched item.

id_call_back will be called when the search engine finds a hash element or a list element which contain <B>noB> or <B>more than 1B> elements. In this case the call-back will have return an id that will be used by the search engine to get the target element.

Both call-back arguments will be:
o The current object (as returned by current_object())
o A list of possible choices
For instances, your callback will be :

 my $id_cb = sub {
    my ($object,@choices) = @_ ;
    return $choice[1] ;

Both call-back are expected to return a scalar value that is either:
o An element name
o An id valid for the list or hash element returned by current_object().


Dominique Dumont, (ddumont at cpan dot org)


Config::Model, Config::Model::Node, Config::Model::AnyId, Config::Model::ListId, Config::Model::HashId, Config::Model::Value,


Dominique Dumont


This software is Copyright (c) 2005-2016 by Dominique Dumont.

This is free software, licensed under:

  The GNU Lesser General Public License, Version 2.1, February 1999

Search for    or go to Top of page |  Section 3 |  Main Index

perl v5.20.3 CONFIG::MODEL::SEARCHELEMENT (3) 2016-04-03

Powered by GSP Visit the GSP FreeBSD Man Page Interface.
Output converted with manServer 1.07.