Config::Model::AnyId

NAME

Config::Model::AnyId - Base class for hash or list element

SYNOPSIS

 use Config::Model;
 # 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 => [
        plain_hash => {
            type       => 'hash',
            index_type => 'string',
            cargo      => {
                type       => 'leaf',
                value_type => 'string',
            },
        },
        bounded_hash => {
            type       => 'hash',      # hash id
            index_type => 'integer',
            # hash boundaries
            min_index => 1, max_index => 123, max_nb => 2,
            # specify cargo held by hash
            cargo => {
                type       => 'leaf',
                value_type => 'string'
            },
        },
        bounded_list => {
            type => 'list',    # list id
            max_index => 123,
            cargo     => {
                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 $steps = 'plain_hash:foo=boo bounded_list=foo,bar,baz
   bounded_hash:3=foo bounded_hash:30=baz 
   hash_of_nodes:"foo node" foo="in foo node" -
   hash_of_nodes:"bar node" bar="in bar node" ';
 $root->load( steps => $steps );
 # dump resulting tree
 print $root->dump_tree;

DESCRIPTION

This class provides hash or list elements for a Config::Model::Node.

The hash index can either be en enumerated type, a boolean, an integer or a string.

CONSTRUCTOR

AnyId object should not be created directly.

Hash or list model declaration

A hash or list element must be declared with the following parameters:

type: Mandatory element type. Must be "hash" or "list" to have a collection element. The actual element type must be specified by "cargo => type".

index_type: Either "integer" or "string". Mandatory for hash.

ordered: Whether to keep the order of the hash keys (default no). (a bit like Tie::IxHash). The hash keys are ordered along their creation. The order can be modified with swap, move_up or move_down.

duplicates: Specify the policy regarding duplicated values stored in the list or as hash values (valid only when cargo type is "leaf"). The policy can be "allow" (default), "suppress", "warn" (which offers the possibility to apply a fix), "forbid". Note that duplicates check cannot be performed when the duplicated value is stored: this happens outside of this object. Duplicates can be check only after when the value is read.

write_empty_value: By default, hash entries without data are not saved in configuration files. Without data means the cargo of the hash key is empty: either its value is undef or all the values of the contained node are also empty. Set this parameter to 1 if the key must be saved in the configuration file even if the hash contains no value for that key. Note that writing hash entries without value may not be supported by all backends. Use with care. Supported only for hash elements.

cargo: Hash ref specifying the cargo held by the hash of list. This has must contain:

type: Can be "node" or "leaf" (default).

config_class_name: Specifies the type of configuration object held in the hash. Only valid when "cargo" "type" is "node".

<other>: Constructor arguments passed to the cargo object. See Config::Model::Node when "cargo->type" is "node". See Config::Model::Value when "cargo->type" is "leaf".

min_index: Specify the minimum value (optional, only for hash and for integer index)

max_index: Specify the maximum value (optional, only for list or for hash with integer index)

max_nb: Specify the maximum number of indexes. (hash only, optional, may also be used with string index type)

default_keys: When set, the default parameter (or set of parameters) are used as default keys hashes and created automatically when the "keys" or "exists" functions are used on an empty hash. You can use "default_keys => 'foo'", or "default_keys => ['foo', 'bar']".

default_with_init

To perform special set-up on children nodes you can also use

   default_with_init =>  {
      foo => 'X=Av Y=Bv',
      bar => 'Y=Av Z=Cv'
   }

When the hash contains leaves, you can also use:

   default_with_init => {
       def_1 => 'def_1 stuff',
       def_2 => 'def_2 stuff'
   }

migrate_keys_from

Specifies that the keys of the hash are copied from another hash in the configuration tree only when the hash is read for the first time after initial load (i.e. once the configuration files are completely read).

   migrate_keys_from => '- another_hash'

migrate_values_from

Specifies that the values of the hash (or list) are copied from another hash (or list) in the configuration tree only when the hash (or list) is read for the first time after initial load (i.e. once the configuration files are completely read).

   migrate_values_from => '- another_hash_or_list'

follow_keys_from

Specifies that the keys of the hash follow the keys of another hash in the configuration tree. In other words, the created hash always has the same keys as the other hash.

   follow_keys_from => '- another_hash'

allow_keys

Specifies authorized keys:

  allow_keys => ['foo','bar','baz']

allow_keys_from

A bit like the "follow_keys_from" parameters. Except that the hash pointed to by "allow_keys_from" specified the authorized keys for this hash.

  allow_keys_from => '- another_hash'

allow_keys_matching

Keys must match the specified regular expression. For instance:

  allow_keys_matching => '^foo\d\d$'

auto_create_keys: When set, the default parameter (or set of parameters) are used as keys hashes and created automatically. (valid only for hash elements) Called with "auto_create_keys => ['foo']", or "auto_create_keys => ['foo', 'bar']".

warn_if_key_match: Issue a warning if the key matches the specified regular expression

warn_unless_key_match: Issue a warning unless the key matches the specified regular expression

auto_create_ids: Specifies the number of elements to create automatically. E.g. "auto_create_ids => 4" initializes the list with 4 undef elements. (valid only for list elements)

convert => [uc | lc ]: The hash key are converted to uppercase (uc) or lowercase (lc).

warp: See "Warp: dynamic value configuration" below.

Warp: dynamic value configuration

The Warp functionality enables an HashId or ListId object to change its default settings (e.g. "min_index", "max_index" or "max_nb" parameters) dynamically according to the value of another "Value" object. (See Config::Model::Warper for explanation on warp mechanism)

For instance, with this model:

 $model ->create_config_class 
  (
   name => 'Root',
   'element'
   => [
       macro => { type => 'leaf',
                  value_type => 'enum',
                  name       => 'macro',
                  choice     => [qw/A B C/],
                },
       warped_hash => { type => 'hash',
                        index_type => 'integer',
                        max_nb     => 3,
                        warp       => {
                                       follow => '- macro',
                                       rules => { A => { max_nb => 1 },
                                                  B => { max_nb => 2 }
                                                }
                                      },
                        cargo => { type => 'node',
                                   config_class_name => 'Dummy'
                                 }
                      },
     ]
  );

Setting "macro" to "A" means that "warped_hash" can only accept one "Dummy" class item .

Setting "macro" to "B" means that "warped_hash" accepts two "Dummy" class items.

Like other warped class, a HashId or ListId can have multiple warp masters (See "Warp follow argument" in Config::Model::Warper:

  warp => { follow => { m1 => '- macro1', 
                        m2 => '- macro2' 
                      },
            rules  => [ '$m1 eq "A" and $m2 eq "A2"' => { max_nb => 1},
                        '$m1 eq "A" and $m2 eq "B2"' => { max_nb => 2}
                      ],
          }

Warp and auto_create_ids or auto_create_keys

When a warp is applied with "auto_create_keys" or "auto_create_ids" parameter, the auto_created items are created if they are not already present. But this warp never removes items that were previously auto created.

For instance, when a tied hash is created with "auto_create => [a,b,c]", the hash contains "(a,b,c)".

Then, once a warp with "auto_create_keys => [c,d,e]" is applied, the hash then contains "(a,b,c,d,e)". The items created by the first auto_create_keys are not removed.

Warp and max_nb

When a warp is applied, the items that do not fit the constraint (e.g. min_index, max_index) are removed.

For the max_nb constraint, an exception is raised if a warp leads to a number of items greater than the max_nb constraint.

Content check

By default, this class provides an optional content check that checks for duplicated values (when "duplicates" parameter is set).

Derived classes can register more global checker with the following method.

add_check_content

This method expects a sub ref with signature "( $self, $error, $warn, $apply_fix )". Where $error and $warn are array ref. You can push error or warning messages there. $apply_fix is a boolean. When set to 1, the passed method can fix the warning or the error. Please make sure to weaken $self to avoid memory cycles.

Example:

 package MyId;
 use Mouse;
 extends qw/Config::Model::HashId/;
 use Scalar::Util qw/weaken/;
 sub setup {
    my $self = shift;
    weaken($self);
    $self-> add_check_content( sub { $self->check_usused_licenses(@_);} )
}

Introspection methods

The following methods returns the current value stored in the Id object (as declared in the model unless they were warped):

min_index

max_index

max_nb

index_type

default_keys

default_with_init

follow_keys_from

auto_create_ids

auto_create_keys

ordered

morph

config_model

get_cargo_type

Returns the object type contained by the hash or list (i.e. returns "cargo -> type").

get_cargo_info

Parameters: "( < what > )"

Returns more info on the cargo contained by the hash or list. "what" may be "value_type" or any other cargo info stored in the model. Returns undef if the requested info is not provided in the model.

get_default_keys

Returns a list (or a list ref) of the current default keys. These keys can be set by the "default_keys" or "default_with_init" parameters or by the other hash pointed by "follow_keys_from" parameter.

name

Returns the object name. The name finishes with ' id'.

config_class_name

Returns the config_class_name of collected elements. Valid only for collection of nodes.

This method returns undef if "cargo" "type" is not "node".

has_fixes

Returns the number of fixes that can be applied to the current value.

Information management

fetch_with_id

Parameters: "( index => $idx , [ check => 'no' ])"

Fetch the collected element held by the hash or list. Index check is 'yes' by default. Can be called with one parameter which is used as index.

get

Get a value from a directory like path. Parameters are:

path

Poor man's version of XPath style path. This string is in the form:

 /foo/bar/4

Each word between the '/' is either an element name or a hash key or a list index.

mode: Either "default", "custom", "user",... See "mode" parameter in <Config::Model::Value/"fetch( ... )">

check: Either "skip", "no"

get_obj: If the path leads to a leaf, this parameter tell whether to return the stored value or the value object.

autoadd: Whether to create missing keys

dir_char_mockup: When the hash key used contains '/', (for instance a directory value), the key cannot be used as is with this method. Because '/' is already used to separate configuration items (this is also important with Config::Model::FuseUI). This parameter specifies how the forbidden '/' char is shown in the path. Default is "<slash>"

set

Parameters: "( path, value )"

Set a value with a directory like path.

copy

Parameters: "( from_index, to_index )"

Deep copy an element within the hash or list. If the element contained by the hash or list is a node, all configuration information is copied from one node to another.

fetch_all

Returns an array containing all elements held by the hash or list.

fetch_value

Parameters: "( idx => ..., mode => ..., check => ...)"

Returns the value held by the "idx" element of the hash or list. This method is only valid for hash or list containing leaves.

See fetch_all_values for "mode" argument documentation and "fetch" in Config::Model::Value for "check" argument documentation.

fetch_summary

Arguments: "( idx => ..., mode => ..., check => ...)"

Like "fetch_value", but returns a truncated value when the value is a string or uniline that is too long to be displayed.

fetch_all_values

Parameters: "( mode => ..., check => ...)"

Returns an array containing all defined values held by the hash or list. (undefined values are simply discarded). This method is only valid for hash or list containing leaves.

With "mode" parameter, this method returns either:

custom: The value entered by the user

preset: The value entered in preset mode

standard: The value entered in preset mode or checked by default.

default: The default value (defined by the configuration model)

See "fetch" in Config::Model::Value for "check" argument documentation.

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

2022-07-28

perl v5.34.0

Questions & Answers