Config::Model::Instance(3pm)

NAME
Config::Model::Instance - Instance of configuration tree

SYNOPSIS
 my $model = Config::Model->new() ;
 $model ->create_config_class ( ... ) ;

 my $inst = $model->instance (root_class_name => 'SomeRootClass',
                              instance_name    => 'some_name');

DESCRIPTION
This module provides an object that holds a configuration tree.

CONSTRUCTOR
An instance object is created by calling instance method on an existing model:

 my $inst = $model->instance (root_class_name => 'SomeRootClass',
                              instance_name => 'test1');

The directory (or directories) holding configuration files is specified within the configuration model. For test purpose you can change the "root" directory with "root_dir" parameter:

root_dir
    Pseudo root directory where to read and write configuration files

backend
    Specify which backend to use. See "write_back ( ... )" for details

skip_read
    When set, configuration files will not be read when creating configuration tree.

Note that the root directory specified within the configuration model will be overridden by "root_dir" parameter.

If you need to load configuration data that are not correct, you can use "force_load => 1". Then, wrong data will be discarded.

METHODS

  name()
Returns the instance name.

  config_root()
Returns the root object of the configuration tree.

  reset_config
Destroy current configuration tree (with data) and returns a new tree with data (and annotations) loaded from disk.

  config_model()
Returns the model (Config::Model object) of the configuration tree.

  annotation_saver()
Returns the object loading and saving annotations. See Config::Model::Annotation for details.

  preset_start ()
All values stored in preset mode are shown to the user as default values. This feature is useful to enter configuration data entered by an automatic process (like hardware scan)

  preset_stop ()
Stop preset mode

  preset ()
Get preset mode

  data( kind, [data] )
The data method provide a way to store some arbitrary data in the instance object.

  load( "..." )
Load configuration tree with configuration data. See Config::Model::Loader for more details

  searcher ( )
Returns an object dedicated to search an element in the configuration model (respecting privilege level).

This method returns a Config::Model::Searcher object. See Config::Model::Searcher for details on how to handle a search.

  wizard_helper ( ... )
This method returns a Config::Model::WizardHelper object. See Config::Model::WizardHelper for details on how to create a wizard widget with this object.

wizard_helper arguments are explained in Config::Model::WizardHelper constructor arguments.

Auto read and write feature
Usually, a program based on config model must first create the configuration model, then load all configuration data.

This feature enables you to declare with the model a way to load configuration data (and to write it back). See Config::Model::AutoRead for details.

  read_root_dir()
Returns root directory where configuration data is read from.

  backend()
Get the preferred backend method for this instance (as passed to the constructor).

  write_root_dir()
Returns root directory where configuration data is written to.

  register_write_back ( backend_name, sub_ref )
Register a sub ref (with the backend name) that will be called with "write_back" method.

  write_back ( ... )
Try to run all subroutines registered with "register_write_back" to write the configuration information until one succeeds (returns true). (See Config::Model::AutoRead for details).

You can specify here a pseudo root dir or another config dir to write configuration data back with "root" and "config_dir" parameters. This will override the model specifications.

You can force to use a backend by specifying "backend => xxx". For instance, "backend => 'augeas'" or "backend => 'custom'".

You can force to use all backend to write the files by specifying "backend => 'all'".

"write_back" will croak if no write call-back are known.

AUTHOR
Dominique Dumont, (ddumont at cpan dot org)

SEE ALSO
Config::Model, Config::Model::Node, Config::Model::Loader, Config::Model::Searcher, Config::Model::Value,