Config::Model::Backend::Yaml - Read and write config as a YAML data structure
version 2.106
use Config::Model ; use Data::Dumper ; # define configuration tree object my $model = Config::Model->new ; $model ->create_config_class ( name => "MyClass", element => [ [qw/foo bar/] => { type => 'leaf', value_type => 'string' }, baz => { type => 'hash', index_type => 'string' , cargo => { type => 'leaf', value_type => 'string', }, }, ], read_config => [ { backend => 'yaml' , config_dir => '/tmp', file => 'foo.yml', auto_create => 1, } ], ) ; my $inst = $model->instance(root_class_name => 'MyClass' ); my $root = $inst->config_root ; my $steps = 'foo=yada bar="bla bla" baz:en=hello baz:fr=bonjour baz:hr="dobar dan"'; $root->load( steps => $steps ) ; $inst->write_back ;
Now, /tmp/foo.yml contains:
/tmp/foo.yml
--- bar: bla bla baz: en: hello fr: bonjour hr: dobar dan foo: yada
This module is used directly by Config::Model to read or write the content of a configuration tree written with YAML syntax in Config::Model configuration tree.
Config::Model
Note:
Undefined values are skipped for list element. I.e. if a list element contains ('a',undef,'b'), the data structure contains 'a','b'.
('a',undef,'b')
'a','b'
YAML file is not created (and may be deleted) when no data is to be written.
If the root node contains a single hash or list element, only the content of this hash is written in a YAML file.
For example, if a class contains:
element => [ baz => { type => 'hash', index_type => 'string' , cargo => { type => 'leaf', value_type => 'string', }, },
If the configuration is loaded with:
$root->load("baz:one=un baz:two=deux")
Then the written YAML file does not show baz:
baz
--- one: un two: deux
Likewise, a YAML file for a class with a single list baz element would be written with:
--- - un - deux
By default, this module uses YAML::Tiny. This module has the advantage of being light and secure. No Perl object can be created with YAML tags so YAML::Tiny can be used with YAML files coming from unutrusted sources.
On the other hand, YAML::Tiny does not support boolean values: it cannot write true and false as plain scalar. true and false are quoted and are not of type boolean from YAML point of view.
true
false
If this is a problem for your configuration files, you can use YAML module which writes true and false without quotes.
Inherited from Config::Model::Backend::Any. The constructor is called by Config::Model::BackendMgr.
Of all parameters passed to this read call-back, only io_handle is used. This parameter must be IO::File object already opened for read.
io_handle
It can also be undef. In which case read() returns 0.
read()
When a file is read, read() returns 1.
Of all parameters passed to this write call-back, only io_handle is used. This parameter must be IO::File object already opened for write.
write() returns 1.
write()
Dominique Dumont, (ddumont at cpan dot org)
Config::Model, Config::Model::BackendMgr, Config::Model::Backend::Any,
Dominique Dumont
This software is Copyright (c) 2005-2017 by Dominique Dumont.
This is free software, licensed under:
The GNU Lesser General Public License, Version 2.1, February 1999
To install Config::Model, copy and paste the appropriate command in to your terminal.
cpanm
cpanm Config::Model
CPAN shell
perl -MCPAN -e shell install Config::Model
For more information on module installation, please visit the detailed CPAN module installation guide.