# $Id: Context.pod,v 1.1 2001/01/21 20:58:39 aigan Exp $ -*-perl-*- =head1 NAME RDF::Service::Context =head1 PUBLIC METHODS These are the methods applicable for all resources. If nothing else is said, the return value is an context object. Unless otherwise stated, the parameters for the methods are resources. A resource is either given by its uri string or a context object holding the resource. Some methods I the object before it's main action. To initialize the object is to ask all the connected interfaces for relevant statings. There is presently two types of initializations; that of the type statements, and that of the other properties. The keyword B is used to indicate that no initialization is done. C<$self> referes to the object those method is invoked. =head2 name() Returns C<< $self->[NODE][NAME] >> =head2 uri() Returns C<< $self->[NODE][URISTR] >> =head2 model() Returns the model =head2 get( $uristr, $ids ) Calls C<< get_context_by_id( $id, $ids >> =head2 get_context_by_id( $id, $ids ) C<$ids> is optional and should only be used by L. Gets the node from the cache or creates a new node. Returns the context. =head2 get_node( $uristr, $ids ) Calls C<< get_node_by_id( $id, $ids ) >> =head2 get_node_by_id( $id, $ids ) C<$ids> is optional and should only be used by L. Gets the node from the cache or creates a new node. Returns the node. =head2 get_model( $uristr ) Creates the model if it doesn't already exist. Returns the model =head2 is_a( $class ) Returns I if C<$self rdf:type $class>. Initialize the types if needed. =head2 could_be_a( $class ) Returns I if C<$self rdf:type $class> or if we currently doesn't B all the types of $self. =head2 is_known_as_a( $class ) Returns I if we B that C<$self rdf:type $class>. =head2 exist_pred( $pred ) Returns I if $self is B to have a $pred property. =head2 type_orderd_list() Returns a reference to a list of the B types of $self. The types is orderd by L. =head2 type() Returns a selection of the orderd types. =head2 rev_type() Same as type, but in the reverse direction. =head2 arc( $point ) Returns a selection of the arcs having $self as subject. If $point is defined, it should be a property, defining which statements to return. =head2 arc_subj( $point ) Returns a selection of the subjects from arcs having $self as object and $point as predicate. =head2 arc_pred() Returns a selection of th predictes from arcs having $self as subject. =head2 arc_obj( $point ) Returns a selection of the objects from arcs having $self as subject and $point as predicate. =head2 arc_obj_list( $point ) Same as arc_obj() but returns a reference to a list. =head2 set( $types, $props ) Calls C and C. =head2 set_types( $types, $trim, $local_changes ) Sets the types of $self to $types, which is a list of types. If C<$trim>, existing types for $self, not mentioned in $types will be removed, providing the model is the same. If C<$local_changes>, the changes will not be forwarded to the interfaces. This parameter is intended for internal use. =head2 set_props( $props, $trim, $local_changes ) The same as set_types(), but for C<$props>. $props = { $pred_uri => [ $obj, ... ], ... }; C<$obj> can be a uri string, context object or a C, in which case it will be takes as a literal. =head2 create_literal( $uristr, $lit_str_ref ) Creates a literal with uri $uristr, or a generated uri, if undef. The content is taken from the scalar ref $lit_str_ref. Returns the lietaral (as a context object). =head2 set_literal( $lit_str_ref ) Changes the value uf the literal $self to the content of $lit_str_ref scalar reference. =head2 types_as_string() Returns a string for debugging purposes, listing the types of $self, and the models that defines them. Example: Types for http://uxn.nu/rdf/2000/09/19/local-data/service/jonas.rit.se.1800979912294474 t http://uxn.nu/rdf/2000/09/19/local-schema#Model m http://uxn.nu/rdf/2000/09/19/local-data#The_Base_Model SOLID 1 t http://www.w3.org/2000/01/rdf-schema#Container m http://uxn.nu/rdf/2000/09/19/local-data#The_Base_Model SOLID 1 t http://uxn.nu/rdf/2000/09/19/local-schema#Service m http://uxn.nu/rdf/2000/09/19/local-data#The_Base_Model SOLID 1 m http://uxn.nu/rdf/2000/09/19/local-data/service/jonas.rit.se.1800979912294474 SOLID 0 t http://www.w3.org/2000/01/rdf-schema#Resource m http://www.w3.org/2000/01/rdf-schema# SOLID 1 =head2 li() Returns the only resource from a container (for example a selection). Dies if more or less than one items exist in the container. =head2 list() Returns a reference to the list of resources in the container $self. =head1 INTERFACE METHODS =head2 init_types() Calls the interfaces init_types() and sets TYPE_ALL. =head2 init_rev_types() Calls the interfaces init_rev_types() and sets REV_TYPE_ALL. =head2 init_rev_subjs() Calls the interfaces init_rev_subjs and sets REV_SUBJ_ALL. =head2 init_rev_objs() Calls the interfaces init_rev_objs() and sets REV_OBJ_ALL. =head2 store_types( @args ) Initializes the types and calls the interfaces store_types(). Sets TYPE_ALL to 2 if all goes well. =head2 store_props( @args ) Initialize REV_SUBJ and calls the interfaces store_props(). Sets REV_SUBJ_ALL to 2 if all foes well. =head2 store Store $self in the interfaces. Also store all unsaved nodes realted to $self. =head2 declare_del_types( $types ) Delete types from $self. =head2 declare_del_rev_types( $res ) Delete rev_types from $self. =head2 declare_literal( $lit_str_ref, $lit ) Makes a literal out of $lit (uristr or resource or undef) and sets the value to $lit_str_ref. =head2 declare_selection( $content, $selection ) Creates and returns the selection resource $selection with the content $content. The content is a reference to a list of (context) resources. =head2 declare_self( $types, $props) Calls C and C. =head2 declare_add_types( $types, $model, $solid ) Adds the $types to $self. Use WMODEL unless $model.  $model should be a node object. If $solid is true, do not try to save the added types in the interfaces. (They are infered or temporary.) Additional types will be infered based on c. =head2 declare_add_dynamic_literal( $pred, $lit_str_ref, $lit_uristr, $arc_uristr, $model ) Add a stating in model $model or WMODEL with $self as subject, $pred as predicate and $lit_uristr as object. The literal is set to $lit_str_ref and the arc is the resource $arc_uristr. =head2 declare_add_prop( $pred, $objm $arc_uristr, $model, $solid ) Calls C. =head2 declare_arc( $pred, $subj, $obj, $uristr, $model, $solid ) Declare the statement in model $model or WMODEL. If $solid, do not try to stor the arc in the interfaces. =head1 AUTHOR Jonas Liljegren Ejonas@paranormal.seE http://jonas.liljegren.org/myself/en/ =head1 COPYRIGHT Copyright (C) 2000-2001 Jonas Liljegren. All Rights Reserved. This module is free software; you can redistribute it and/or modify it under the same terms as Perl itself. =head1 SUPPORT Comments and bug reports should go to rdf@uxn.nu. =head1 CREDITS Stefan Andersson =head1 SEE ALSO =for HTML Wraf L