NAME

       PGObject::Type::Registry - Registration of types for handing db types

SYNOPSIS

         PGObject::Type::Registry->add_registry('myapp'); # required

         PGObject::Type::Registry->register_type(
            registry => 'myapp', dbtype => 'int4',
            apptype => 'PGObject::Type::BigFloat'
         );

         # to get back a type:
         my $number = PGObject::Type::Registry->deserialize(
            registry => 'myapp', dbtype => 'int4',
            dbstring => '1023'
         );

         # To get registry data:
         my %registry = PGObject::Type::Registry->inspect(registry => 'myapp');

DESCRIPTION

       The PGObject type registry stores data for serialization and deserialization relating to
       the database.

USE

       Generally we like to separate applications into their own registries so that different
       libraries can be used in a more harmonious way.

CREATING A REGISTRY

       You must create a registry before using it.  This is there to ensure that we make sure
       that subtle problems are avoided and strings returned when serialized types expected.
       This is idempotent and repeat calls are safe. There is no abiltiy to remove an existing
       registry though you can loop through and remove the existing registrations.

   new_registry(name)

REGISTERING A TYPE

   register_type
       Args:

           registry => 'default', #warning thrown if not specified
           dbtype => [required], #exception thrown if not specified
           apptype => [required], #exception thrown if not specified

       Use:

       This registers a type for use by PGObject.  PGObject calls with the same registry key will
       serialize to this type, using the from_db method provided.

       from_db will be provided two arguments.  The first is the string from the database and the
       second is the type provided.  The second argument is optional and passed along for the db
       interface class's use.

       A warning is thrown if no

UNREGISTERING A TYPE

       To unregister a type, you provide the dbtype and registry information, both of which are
       required.  Note that at this time this is rarely needed.

   unregister_type

DESERIALIZING A VALUE

   deserialize
       This function deserializes a data from a db string.

       Mandatory args are dbtype and dbstring The registry arg should be provided but if not, a
       warning will be issued and 'default' will be used.

       This function returns the output of the from_db method.

   deserializer
       This returns a coderef to deserialize data from a db string. The coderef should be called
       with a single argument: the argument that would be passed as 'dbstring' into
       "deserialize". E.g.:

          my $deserializer = PGObject::Type::Registry->deserializer(dbtype => $type);
          my $value = $deserializer->($dbvalue);

       Mandatory argument is dbtype.  The registry arg should be provided but if not, a warning
       will be issued and 'default' will be used.

       This function returns the output of the "from_db" method of the registered class.

   rowhash_deserializer
       This returns a coderef to deserialize data from a call to e.g.  "fetchrow_arrayref". The
       coderef should be called with a single argument: the hash that holds the row values with
       the keys being the column names.

       Mandatory argument is "types", which is either an arrayref or hashref.  In case of a
       hashref, the keys are the names of the columns to be expected in the data hashrefs. The
       values are the types (same as the "dbtype" parameter of the "deserialize" method). In case
       of an arrayref, an additional argument "columns" is required, containing the names of the
       columns in the same order as "types".

       The registry arg should be provided but if not, a warning will be issued and 'default'
       will be used.

       This function returns the output of the "from_db" method of the registered class.

INSPECTING A REGISTRY

       Sometimes we need to see what types are registered.  To do this, we can request a copy of
       the registry.

   inspect($name)
       $name is required.  If it does not exist an exception is thrown.

   list()
       Returns a list of existing registries.

COPYRIGHT AND LICENSE

       COPYRIGHT (C) 2017-2021 The LedgerSMB Core Team

       Redistribution and use in source and compiled forms with or without modification, are
       permitted provided that the following conditions are met:

       •   Redistributions of source code must retain the above copyright notice, this list of
           conditions and the following disclaimer as the first lines of this file unmodified.

       •   Redistributions in compiled form must reproduce the above copyright notice, this list
           of conditions and the following disclaimer in the source code, documentation, and/or
           other materials provided with the distribution.

       THIS SOFTWARE IS PROVIDED BY THE AUTHOR(S) "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
       INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A
       PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR(S) BE LIABLE FOR ANY
       DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
       NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
       PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER
       IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY
       WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.