##########
SystemData
##########


****
NAME
****


Kernel::System::SystemData - key/value store for system data


***********
DESCRIPTION
***********


Provides key/value store for system data


****************
PUBLIC INTERFACE
****************


new()
=====


Don't use the constructor directly, use the ObjectManager instead:


.. code-block:: perl

     my $SystemDataObject = $Kernel::OM->Get('Kernel::System::SystemData');



SystemDataAdd()
===============


add a new \ ``SystemData``\  value.

Result is true if adding was OK, and false if it failed, for instance because
the key already existed.

If your keys contain '::' this will be used as a separator. This allows you to
later for instance fetch all keys that start with 'SystemRegistration::' in
one go, using SystemDataGetGroup().


.. code-block:: perl

     my $Result = $SystemDataObject->SystemDataAdd(
         Key    => 'SomeKey',
         Value  => 'Some Value',
         UserID => 123,
     );
 
     my $Result = $SystemDataObject->SystemDataAdd(
         Key    => 'SystemRegistration::Version',
         Value  => 'Some Value',
         UserID => 123,
     );



SystemDataGet()
===============


get system data for key


.. code-block:: perl

     my $SystemData = $SystemDataObject->SystemDataGet(
         Key => 'Znuny Version',
     );


returns value as a simple scalar, or undef if the key does not exist.
keys set to NULL return an empty string.


SystemDataGroupGet()
====================


returns a hash of all keys starting with the Group.
For instance the code below would return values for
'SystemRegistration::UniqueID', 'SystemRegistration::UpdateID',
and so on.


.. code-block:: perl

     my %SystemData = $SystemDataObject->SystemDataGroupGet(
         Group => 'SystemRegistration',
     );


returns


.. code-block:: perl

     %SystemData = (
         UniqueID => 'CDC782BE-E483-11E2-83DA-9FFD99890B3C',
         UpdateID => 'D8F55850-E483-11E2-BD60-9FFD99890B3C'
         # ...
     );



SystemDataUpdate()
==================


update system data

Returns true if update was successful or false if otherwise - for instance
if key did not exist.


.. code-block:: perl

     my $Result = $SystemDataObject->SystemDataUpdate(
         Key    => 'Znuny Version',
         Value  => 'Some New Value',
         UserID => 123,
     );



SystemDataDelete()
==================


update system data

Returns true if delete was successful or false if otherwise - for instance
if key did not exist.


.. code-block:: perl

     $SystemDataObject->SystemDataDelete(
         Key    => 'Znuny Version',
         UserID => 123,
     );



_SystemDataCacheKeyDelete()
===========================


This will delete the cache for the given key and for all groups, if needed.

For a key such as 'Foo::Bar::Baz', it will delete the cache for 'Foo::Bar::Baz'
as well as for the groups 'Foo::Bar' and 'Foo'.


.. code-block:: perl

     $Success = $SystemDataObject->_SystemDataCacheKeyDelete(
         Key => 'SystemRegistration::Version::DB',
     );