Object Names and IdHandler Service Contract

Object Names

acs_objects.name(object_id)

Obviously, this is highly undesirable since it is not scalable at all. Therefore, a new way had to be found to get the name of an object:

-------------------
-- NAMED OBJECTS --
-------------------

create table acs_named_objects (
	object_id	integer not null
			constraint acs_named_objs_pk primary key
			constraint acs_named_objs_object_id_fk
			references acs_objects(object_id) on delete cascade,
	object_name	varchar2(200),
	package_id	integer
			constraint acs_named_objs_package_id_fk
			references apm_packages(package_id) on delete cascade
);

create index acs_named_objs_name_ix on acs_named_objects (substr(upper(object_name),1,1));
create index acs_named_objs_package_ix on acs_named_objects(package_id);

begin
        acs_object_type.create_type (
                supertype       =>      'acs_object',
                object_type     =>      'acs_named_object',
                pretty_name     =>      'Named Object',
                pretty_plural   =>      'Named Objects',
                table_name      =>      'acs_named_objects',
                id_column       =>      'object_id'
        );
end;
/
show errors

In that way, when having to display a list of objects, one can simply join the acs_named_objects table to get the names and package_ids in an easy and - more importantly - fast and scalable way.

The only shortcoming of this solution is the disregard of internationalization, but in cases where there objects in more than one language, it should be the triggers / pl/sql procs task to make sure that acs_named_objects contains names in the default language if possible.

IdHandler Service Contract

First, we need to know that package_id of the package responsible for the object. This information is currently impossible to get since we would need to go up the context hierarchy until we finally get hold of an apm_package object. But lets assume we get this information by using the new acs_named_objects table, then we would need to figure out the url to that package instance. This can be done, but again by calling a highly unefficient pl/sql proc. But even then we would need the local url to the page being able to display a certain object. Since a package may have more than one type of objects (i.e. file folders, files, file versions), we can not simply store additional package information about which page to call to display an object.

The solution to this kind of problem is by not resolving the url at all during display-time, but doing so at the time the user actually wants to see an object. The links would simply direct to /o/$object_id, which is a global virtual-url-handling page that will figure out the package instance url (by using acs_named_objects and the pl/sql proc) and then relying upon a Service Contract to get the local url - that means every package holding displayable objects should implement this interface for its objects:

declare
    v_id	integer;
begin
    v_id :=  acs_sc_contract.new(
	    contract_name => 'AcsObject',
	    contract_desc => 'Acs Object Id Handler'
    );
    v_id := acs_sc_msg_type.new(
	    msg_type_name => 'AcsObject.PageUrl.InputType',
	    msg_type_spec => 'object_id:integer'
    );
    v_id := acs_sc_msg_type.new(
	    msg_type_name => 'AcsObject.PageUrl.OutputType',
	    msg_type_spec => 'page_url:string'
    );
    v_id := acs_sc_operation.new(
	    contract_name => 'AcsObject',
	    operation_name => 'PageUrl',
	    operation_desc => 'Returns the package specific url to a page
that displays an object',
	    operation_iscacheable_p => 'f',
	    operation_nargs => 1,
	    operation_inputtype => 'AcsObject.PageUrl.InputType',
	    operation_outputtype => 'AcsObject.PageUrl.OutputType'
    );

    v_id := acs_sc_impl.new (
              'AcsObject',
              'apm_package_idhandler',
              'acs-kernel'
    );
    v_id := acs_sc_impl.new_alias (
              'AcsObject',
              'apm_package_idhandler',
              'PageUrl',
              'apm_pageurl',
              'TCL'
    );
    acs_sc_binding.new (
              contract_name => 'AcsObject',
              impl_name => 'apm_package_idhandler'
    );                             

    v_id := acs_sc_impl.new (
              'AcsObject',
              'user_idhandler',
              'acs-kernel'
    );
    v_id := acs_sc_impl.new_alias (
              'AcsObject',
              'user_idhandler',
              'PageUrl',
              'acs_user::pageurl',
              'TCL'
    );
    acs_sc_binding.new (
              contract_name => 'AcsObject',
              impl_name => 'user_idhandler'
    );                             
end;

ad_proc -public apm_pageurl { object_id } {
    Service Contract Proc to resolve a URL for a package_id
} {
    return
}

namespace eval acs_user {
    ad_proc -public pageurl { object_id } {
	Service Contract Proc to resolve a URL for a user_id
    } {
	return "shared/community-member?user_id=$object_id"
    }
}