Config::Model::SearcheUser Contributed Perl DocumentConfig::Model::Searcher(3)NAMEConfig::Model::Searcher - Search an element in a configuration model
VERSION
version 1.235
SYNOPSIS
use Config::Model;
use Log::Log4perl qw(:easy);
Log::Log4perl->easy_init($WARN);
# define configuration tree object
my $model = Config::Model->new;
$model->create_config_class(
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'
DESCRIPTION
This modules provides a way to search for a configuration element in a
configuration tree.
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:
· 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.
· An automatic search where you provide call-back that will resolve
the ambiguities in case of multiple paths.
CONSTRUCTOR
The constructor should be used only by Config::Model::Node.
Methods
get_searchable_elements
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).
reset
Re-initialize the search engine to redo the search from start
searched
Returns the searched element name.
Manual searchnext_step()
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()".
next_choice()
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()".
current_object()
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 no or more than 1 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:
· The current object (as returned by "current_object()")
· 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:
· An element name
· An id valid for the list or hash element returned by
"current_object()".
AUTHOR
Dominique Dumont, (ddumont at cpan dot org)
SEE ALSO
Config::Model, Config::Model::Node, Config::Model::AnyId,
Config::Model::ListId, Config::Model::HashId, Config::Model::Value,
perl v5.14.1 2011-07-22 Config::Model::Searcher(3)