Config::Model::Instance(3pm) User Contributed Perl Documentation Config::Model::Instance(3pm)
NAME
Config::Model::Instance - Instance of configuration tree
VERSION
version 2.021
SYNOPSIS
use Config::Model;
use Log::Log4perl qw(:easy);
use File::Path ;
Log::Log4perl->easy_init($WARN);
# setup a dummy popcon conf file
my $wr_dir = '/tmp/etc/';
my $conf_file = "$wr_dir/popularity-contest.conf" ;
unless (-d $wr_dir) {
mkpath($wr_dir, { mode => 0755 })
|| die "can't mkpath $wr_dir: $!";
}
open(my $conf,"> $conf_file" ) || die "can't open $conf_file: $!";
$conf->print( qq!MY_HOSTID="aaaaaaaaaaaaaaaaaaaa"
!,
qq!PARTICIPATE="yes"
!,
qq!USEHTTP="yes" # always http
!,
qq!DAY="6"
!);
$conf->close ;
my $model = Config::Model->new;
# PopCon model is provided. Create a new Config::Model::Instance object
my $inst = $model->instance (root_class_name => 'PopCon',
root_dir => '/tmp',
);
my $root = $inst -> config_root ;
print $root->describe;
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.
check
'yes', 'skip' or 'no'
on_change_cb
Call back this function whenever "notify_change" is called. Called with arguments: "name => <root node element name>, index =>
<index_value>"
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 (equivalent
to "check =" 'no'> ).
METHODS
name()
Returns the instance name.
config_root()
Returns the root object of the configuration tree.
read_check()
Returns how to check read files.
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
preset_clear()
Clear all preset values stored.
layered_start ()
All values stored in layered 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)
layered_stop ()
Stop layered mode
layered ()
Get layered mode
layered_clear()
Clear all layered values stored.
get_data_mode
Returns 'normal' or 'preset' or 'layered'. Does not take into account initial_load.
initial_load_stop ()
Stop initial_load mode. Instance is built with initial_load as 1. Read backend will clear this value once the first read is done.
initial_load ()
Get initial_load 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 ( ... )
Deprecated. Call "iterator" instead.
iterator
This method returns a Config::Model::Iterator object. See Config::Model::Iterator for details.
Arguments are explained in Config::Model::Iterator 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::BackendMgr
for details.
backend()
Get the preferred backend method for this instance (as passed to the constructor).
root_dir()
Returns root directory where configuration data is read from or written to.
register_write_back ( node_location )
Register a node path that will be called back with "write_back" method.
notify_change
Notify that some data has changed in the tree.
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 directory or another config directory 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.
apply_fixes
Scan the tree and apply fixes that are attached to warning specifications. See "warn_if_match" or "warn_unless_match" in "" in
Config::Model::Value.
needs_save
Returns 1 (or more) if the instance contains data that needs to be saved.
list_changes
In list context, returns a array ref of strings describing the changes. In scalar context, returns a big string. Useful to print.
AUTHOR
Dominique Dumont, (ddumont at cpan dot org)
SEE ALSO
Config::Model, Config::Model::Node, Config::Model::Loader, Config::Model::Searcher, Config::Model::Value,
perl v5.14.2 2012-11-09 Config::Model::Instance(3pm)