Provided by: libpgobject-perl_2.000002-1_all bug

NAME

       PGObject - A toolkit integrating intelligent PostgreSQL dbs into Perl objects

VERSION

       Version 2.0.2

SYNPOSIS

       To use without caching:

         use PGObject;

       To use with caching:

         use PGObject ':cache';

       To get basic info from a function

         my $f_info = PGObject->function_info(
             dbh        =>  $dbh,
             funcname   =>  $funcname,
             funcschema =>  'public',
         );

       To get info about a function, filtered by first argument type

         my $f_info = PGObject->function_info(
             dbh        =>  $dbh,
             funcname   =>  $funcname,
             funcschema =>  'public',
             funcprefix =>  'test__',
             objtype    =>  'invoice',
             objschema  =>  'public',
         );

       To call a function with enumerated arguments

         my @results = PGObject->call_procedure(
             dbh          =>  $dbh,
             funcname     => $funcname,
             funcprefix =>  'test__',
             funcschema   => $funcname,
             args         => [$arg1, $arg2, $arg3],
         );

       To do the same with a running total

         my @results = PGObject->call_procedure(
             dbh           =>  $dbh,
             funcname      => $funcname,
             funcschema    => $funcname,
             args          => [$arg1, $arg2, $arg3],
             running_funcs => [{agg => 'sum(amount)', alias => 'running_total'}],
         );

DESCRIPTION

       PGObject contains the base routines for object management using discoverable stored
       procedures in PostgreSQL databases.  This module contains only common functionality and
       support structures, and low-level API's.  Most developers will want to use more functional
       modules which add to these functions.

       The overall approach here is to provide the basics for a toolkit that other modules can
       extend.  This is thus intended to be a component for building integration between
       PostgreSQL user defined functions and Perl objects.

       Because decisions such as state handling are largely outside of the scope of this module,
       this module itself does not do any significant state handling.  Database handles (using
       DBD::Pg 2.0 or later) must be passed in on every call.  This decision was made in order to
       allow for diversity in this area, with the idea that wrapper classes would be written to
       implement this.

FUNCTIONS

   clear_info_cache
       This function clears the info cache if this was loaded with caching enabled.

       The cache is also automatically cleared when a function that was run could not be found
       (this could be caused by updating the db).

   function_info(%args)
       Arguments:

       dbh (required)
           Database handle

       funcname (required)
           function name

       funcschema (optional, default 'public')
           function schema

       funcprefix (optiona, default '')
           Prefix for the function.  This can be useful for separating functions by class.

       argtype1 (optional)
           Name of first argument type.  If not provided, does not filter on this criteria.

       argschema (optional)
           Name of first argument type's schema.  If not provided defaults to 'public'

       This function looks up basic mapping information for a function.  If more than one
       function is found, an exception is raised.  This function is primarily intended to be used
       by packages which extend this one, in order to accomplish stored procedure to object
       mapping.

       Return data is a hashref containing the following elements:

       args
           This is an arrayref of hashrefs, each of which contains 'name' and 'type'

       name
           The name of the function

       num_args
           The number of arguments

   call_procedure(%args)
       Arguments:

       funcname
           The function name

       funcschema
           The schema in which the function resides

       funcprefix (optiona, default '')
           Prefix for the function.  This can be useful for separating functions by class.

       args
           This is an arrayref.  Each item is either a literal value, an arrayref, or a hashref
           of extended information.  In the hashref case, the type key specifies the string to
           use to cast the type in, and value is the value.

       orderby
           The list (arrayref) of columns on output for ordering.

       running_funcs
           An arrayref of running windowed aggregates.  Each contains two keys, namely 'agg' for
           the aggregate and 'alias' for the function name.

           These are aggregates, each one has appended 'OVER (ROWS UNBOUNDED PRECEDING)' to it.

       registry
           This is the name of the registry used for type conversion.  It can be omitted and
           defaults to 'default.'  Note that use of a non-standard registry currently does *not*
           merge changes from the default registry, so you need to reregister types in non-
           default registries when you create them.

           Please note, these aggregates are not intended to be user-supplied.  Please only allow
           whitelisted values here or construct in a tested framework elsewhere.  Because of the
           syntax here, there is no sql injection prevention possible at the framework level for
           this parameter.

   new_registry($registry_name)
       Creates a new registry if it does not exist.  This is useful when segments of an
       application must override existing type mappings.

       This is deprecated and throws a warning.

       Use PGObject::Type::Registry->new_registry($registry_name) instead.

       This no longer returns anything of significance.

   register_type(pgtype => $tname, registry => $regname, perl_class => $pm)
       DEPRECATED

       Registers a type as a class.  This means that when an attribute of type $pg_type is
       returned, that PGObject will automatically return whatever $perl_class->from_db returns.
       This allows you to have a db-specific constructor for such types.

       The registry argument is optional and defaults to 'default'

       If the registry does not exist, an error is raised.  if the pg_type is already registered
       to a different type, this returns 0.  Returns 1 on success.

       Use PGObject::Type::Registry->register_type() instead.

   unregister_type(pgtype => $tname, registry => $regname)
       Deprecated.

       Tries to unregister the type.  If the type does not exist, returns 0, otherwise returns 1.
       This is mostly useful for when a specific type must make sure it has the slot.  This is
       rarely desirable.  It is usually better to use a subregistry instead.

WRITING PGOBJECT-AWARE HELPER CLASSES

       One of the powerful features of PGObject is the ability to declare methods in types which
       can be dynamically detected and used to serialize data for query purposes. Objects which
       contain a pgobject_to_db() or a to_db() method, that method will be called and the return
       value used in place of the object.  This can allow arbitrary types to serialize themselves
       in arbitrary ways.

       For example a date object could be set up with such a method which would export a string
       in yyyy-mm-dd format.  An object could look up its own definition and return something
       like :

          { cast => 'dbtypename', value => '("A","List","Of","Properties")'}

       If a scalar is returned that is used as the serialized value.  If a hashref is returned,
       it must follow the type format:

         type  => variable binding type,
         cast  => db cast type
         value => literal representation of type, as intelligible by DBD::Pg

   REQUIRED INTERFACES
       Registered types MUST implement a $class->from_db function accepts the string from the
       database as its only argument, and returns the object of the desired type.

       Any type MAY present an $object->to_db() interface, requiring no arguments, and returning
       a valid value.  These can be hashrefs as specified above, arrayrefs (converted to
       PostgreSQL arrays by DBD::Pg) or scalar text values.

   UNDERSTANDING THE REGISTRY SYSTEM
       Note that 2.0 moves the registry to a service module which handles both registry and
       deserialization of database types.  This is intended to be both cleaner and more flexible
       than the embedded system in 1.x.

       The registry system allows Perl classes to "claim" PostgreSQL types within a certain
       domain.  For example, if I want to ensure that all numeric types are turned into
       Math::BigFloat objects, I can build a wrapper class with appropriate interfaces, but
       PGObject won't know to convert numeric types to this new class, so this is what
       registration is for.

       By default, these mappings are fully global.  Once a class claims a type, unless another
       type goes through the trouble of unregisterign the first type and making sure it gets the
       authoritative spot, all items of that type get turned into the appropriate Perl object
       types.  While this is sufficient for the vast number of applications, however, there may
       be cases where names conflict across schemas or the like.  To address this application
       components may create their own registries.  Each registry is fully global, but
       application components can specify non-standard registries when calling procedures, and
       PGObject will use only those components registered on the non-standard registry when
       checking rows before output.

       Backwards Incompatibilities from 1.x

       Deserialization occurs in a context which specifies a registry.  In 1.x there were no
       concerns about default mappings but now this triggers a warning.  The most basic and
       frequently used portions of this have been kept but return values for registering types
       has changed.  We no longer provide a return variable but throw an exception if the type
       cannot be safely registered.

       This follows a philosophy of throwing exceptions when guarantees cannot be met.

       We now throw warnings when the default registry is used.

       Longer-run, deserializers should use the PGObject::Type::Registry interface directly.

WRITING TOP-HALF OBJECT FRAMEWORKS FOR PGOBJECT

       PGObject is intended to be the database-facing side of a framework for objects.  The
       intended structure is for three tiers of logic:

       Database facing, low-level API's
       Object management modules
       Application handlers with things like database connection management.

       By top half, we are referring to the second tier.  The third tier exists in the client
       application.

       The PGObject module provides only low-level API's in that first tier.  The job of this
       module is to provide database function information to the upper level modules.

       We do not supply type information, If your top-level module needs this, please check out
       https://code.google.com/p/typeutils/ which could then be used via our function mapping
       APIs here.

   Safely Handling Memoization of Catalog Lookups
       It is important to remember, when writing PGObject top half frameworks that the catalog
       lookups may be memoized and may come back as a data structure.  This means that changes to
       the structures returned from get_function_info() in this module and similar functions in
       other catalog-bound modules may not be safe to modify in arbitrary ways.  Therefore we
       recommend that the return values from catalog-lookup functions are treated as immutable.

       Normalizing output is safe provided there are no conflicts between naming conventions.
       This is usually true since different naming conventions would interfere withmapping.
       However, there could be cases where it is not true, for example, where two different
       mapping modules agree on a subset of normalization conventions but differ on some details.
       The two might safely handle the same conventions but normalize differently resulting in
       conflicts of both were used.

A BRIEF GUIDE TO THE NAMESPACE LAYOUT

       Most names underneath PGObject can be assumed to be top-half modules and modules under
       those can be generally assumed to be variants on those.  There are, however, a few
       reserved names:

       ::Debug is reserved for debugging information.  For example, functions which retrieve
       sources of functions, or grab diagnostics, or the like would go here.
       ::Test is reserved for test framework extensions applible only here
       ::Type is reserved for PG aware type classes.
           For example, one might have PGObject::Type::BigFloat for a Math::Bigfloat wrapper, or
           PGObject::Type::DateTime for a DateTime wrapper.

       ::Util is reserved for utility functions and classes.

AUTHOR

       Chris Travers, "<chris.travers at gmail.com>"

BUGS

       Please report any bugs or feature requests to "bug-pgobject at rt.cpan.org", or through
       the web interface at <http://rt.cpan.org/NoAuth/ReportBug.html?Queue=PGObject>.  I will be
       notified, and then you'll automatically be notified of progress on your bug as I make
       changes.

SUPPORT

       You can find documentation for this module with the perldoc command.

           perldoc PGObject

       You can also look for information at:

       ·   RT: CPAN's request tracker (report bugs here)

           <http://rt.cpan.org/NoAuth/Bugs.html?Dist=PGObject>

       ·   AnnoCPAN: Annotated CPAN documentation

           <http://annocpan.org/dist/PGObject>

       ·   CPAN Ratings

           <http://cpanratings.perl.org/d/PGObject>

       ·   Search CPAN

           <http://search.cpan.org/dist/PGObject/>

ACKNOWLEDGEMENTS

       This code has been loosely based on code written for the LedgerSMB open source accounting
       and ERP project.  While that software uses the GNU GPL v2 or later, this is my own
       reimplementation, based on my original contributions to that project alone, and it differs
       in significant ways.   This being said, without LedgerSMB, this module wouldn't exist, and
       without the lessons learned there, and the great people who have helped make this
       possible, this framework would not be half of what it is today.

SEE ALSO

       PGObject::Simple - Simple mapping of object properties to stored proc args
       PGObject::Simple::Role - Moose-enabled wrapper for PGObject::Simple

COPYRIGHT

       COPYRIGHT (C) 2013-2014 Chris Travers COPYRIGHT (C) 2014-2017 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.