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Module-Generic-v1.1.1
River stage two • 17 direct dependents • 20 total dependents
/ Module::Generic::Dynamic

NAME

Module::Generic::Dynamic - Dynamic Object Class

SYNOPSIS

package My::Module;
use parent qw( Module::Generic::Dynamic );

# Then, instantiating an object
my $object = My::Module->new({
    name => 'Test Product',
    quantity => 20,
    metadata => { sku => 'ABC123', price => 99.99 },
    tags => [qw( product entrepreneurship capital )],
    created => '2023-11-18T10:30:00',
    is_active => 1,
    url => 'https://example.com',
    file_path => './config.ini',
});

# Accessing methods
print $object->name; # Test Product
print $object->metadata->sku; # ABC123
print $object->tags->join(','); # product,entrepreneurship,capital
print $object->created->year; # 2023

# Dynamic method creation via AUTOLOAD
$object->version('1.2.3');
print $object->version->stringify; # 1.2.3

VERSION

v1.3.0

DESCRIPTION

Module::Generic::Dynamic provides a framework for dynamically creating classes and methods based on an input hash reference. It automatically generates accessor methods for each key-value pair, inferring the appropriate data type and handling method creation at runtime using AUTOLOAD.

This module is particularly useful for creating flexible, data-driven objects where the structure is not known in advance. It supports a wide range of data types, including scalars, hashes, arrays, booleans, URIs, UUIDs, IP addresses, versions, files, code references, globs, and custom objects.

For more granular control over the method to be used for each data key-value, use "_set_get_class" in Module::Generic

METHODS

new

Provided with a hash reference of data, this creates a new object and dynamically generates a class based on the calling package name. For each key-value pair in the hash, it creates an accessor method and assigns an appropriate handler based on the data type:

If a key results in an invalid method name (e.g., starting with digits), it is sanitized by removing non-alphanumeric characters and leading digits.

Example:

my $obj = Module::Generic::Dynamic->new({
    name => 'Test',
    is_active => 1,
    url => 'https://example.com',
    file => './config.ini',
});
print $obj->name; # Test
print $obj->is_active; # 1 (Module::Generic::Boolean)
print $obj->url->host; # example.com
print $obj->file->basename; # config.ini

AUTOLOAD

Dynamically creates accessor methods for undefined method calls based on the method name and the first argument’s type (if provided). It uses the same type-guessing logic as new, inferring handlers from:

  • Method name patterns (e.g., is_active for boolean, url for URI). =item * Argument types (e.g., JSON::PP::Boolean, hash, array, scalar). =item * Value formats (e.g., UUID, IP address, file path).

If no arguments are provided (getter call), the method is created based on the method name. For example:

my $obj = Module::Generic::Dynamic->new;
$obj->url('https://example.com');
print $obj->url->host; # example.com
print $obj->is_active; # Creates boolean accessor, returns undef

Invalid inputs (e.g., non-UUID values for id fields) fall back to "_set_get_scalar_as_object" in Module::Generic.

SERIALISATION

Serialisation is supported for CBOR, Sereal, Storable::Improved, and Storable. The module implements FREEZE, THAW, STORABLE_freeze, STORABLE_thaw, and TO_JSON to handle object serialization and deserialization, preserving data types and structure.

Example:

my $obj = Module::Generic::Dynamic->new({ name => 'Test', tags => [qw( product test )] });
my $data = $obj->serialise( $obj, serialiser => 'Storable::Improved' );
my $new_obj = Module::Generic->new->deserialise( data => $data, serialiser => 'Storable::Improved' );
print $new_obj->name; # Test
print $new_obj->tags->join(','); # product,test

THREAD SAFETY WARNING

This module is not thread-safe.

Module::Generic::Dynamic dynamically creates packages and injects methods into symbol tables at runtime using eval. In multi-threaded environments (Perl ithreads), this can cause:

  • Race conditions between threads attempting to create the same symbol.

  • Corrupted symbol tables if a method is installed while another thread is reading or writing from the same class.

  • Use this module only during application initialization, before any threads are spawned.

  • Avoid invoking new or triggering AUTOLOAD from within a thread.

  • In persistent environments (e.g., mod_perl), precompile structures at startup.

ERROR HANDLING

Errors in new and AUTOLOAD, such as invalid parameters or failed method creation, return undef with an error object accessible via $obj->error. Check for errors to handle failures gracefully:

my $obj = Module::Generic::Dynamic->new({ name => 'Test' });
die $obj->error if !defined $obj;

Invalid method names (e.g., starting with digits) are sanitised by removing non-alphanumeric characters and leading digits, or ignored if no valid name remains.

LIMITATIONS

  • Invalid method names (e.g., 123invalid) are sanitised or ignored, which may lead to unexpected behavior if not checked.

  • Type guessing is conservative to avoid false positives. For example, a string like /api/v1 is treated as a scalar unless the key name suggests a file (e.g., file_path).

  • Ambiguous inputs (e.g., a number that could be a version or integer) may default to a less specific handler (e.g., "_set_get_number" in Module::Generic).

Users can override type guessing by explicitly using "_set_get_class" in Module::Generic for more control.

AUTHOR

Jacques Deguest <jack@deguest.jp>

COPYRIGHT & LICENSE

Copyright (c) 2000-2024 DEGUEST Pte. Ltd.

You can use, copy, modify and redistribute this package and associated files under the same terms as Perl itself.