Template functions for fetching information collection objects

*Title: Template functions for fetching information collection objects.

*Original author: Kristian Hole

*Description:

New functions for fetching information collections have been added to improve
getting information from information-collections.

*Documentation:

Fetching information collections:

fetch('content','collected_info_list',  hash(
             [ 'object_id', object id,    ]
             [ 'user_id', user_id,        ]
             [ 'user_identifier', string, ]
             [ 'limit', integer,          ]
             [ 'offset', integer,         ]
             [ 'sort_by', array           ] ) )

Returns:
Array of information collections, matching the parameters set

Parameters:

'object_id' - ID of an object we fetch collections for.

'user_id' - ID of the user to fetch collections for. This is not stored for
            old collections if you upgrade, only to new collections

'user_identifier' - A hash of the userid stored in the collection, only useful
                    for old collections.

'limit' - The maximum number of items to fetch

'offset' - The item to start the fetch, eg, if offset is 2 the first 2 elements
           are skipped

'sort_by' - Array specifying sorting, on the form array( 'field', direction )
            where 'field' is either id, contentobject_id, user_identifier,
                  user_id, created or modified
            and 'direction' is either true() for ASC or false() for DESC

            you can also sort by more elements by using and array on the form:
            array( array( 'field1', dir1 ), array( 'field2', dir2 ) )

Example:

{def $res=fetch('content','collected_info_list',
                   hash( 'object_id', 57,
                         'limit', 10,
                         'offset', 2,
                         'sort_by', array(  array( 'user_id',false() ),
                                            array( 'created', false() ) ) ) )}


$res will now contain 10 information collections starting at element 2, sorted
first by user_id and then created time, which are collected by the content
object with ID 57.

Example 2:

{def $res=fetch('content','collected_info_list',
       hash( 'user_id', 14,
             'sort_by', array( 'created',false())
             )
          ) )}


$res will now contain all information collections by user with user_id 14
sorted by the creation date.


Fetching information collection counts:

fetch('content','collected_info_count',  hash(
             [ 'object_id', object id,    ]
             [ 'user_id', user_id,        ]
             [ 'user_identifier', string  ] ) )

Returns:
A count of the number of the information collections, matching the parameters
set.


Parameters:

'object_id' - ID of an object we fetch collections for.

'user_id' - ID of the user to fetch collections for. This is not stored for old
            collections if you upgrade, only to new collections

'user_identifier' - A hash of the userid stored in the collection, only useful
                    for old collections.


Example:

{def $count=fetch('content','collected_info_count',
        hash( 'object_id', 57,
              'user_id', 14 ) )}

Returns:
The number of information collections collected by content object 57, created
by the user with id 14.

NOTE:
If you upgrade from a previous version of Exponential, the user_id field for old
information collections are 0. New collections will get the user_id properly
set when information is submitted.