SIS - Application Programmatic Interface, Reference Manual - ICS ...

SIS-Application Programmatic Interface, Reference Manual
int GET_TO_VALUE(sessionID, set_id_expr)
Apply get_to_value() on set set_id_expr and return the answer set. If
set_id_expr is SET_ID(0) then apply query on object the condition is
evaluated for.
int GET_LINK_FROM_BY_CATEGORY(sessionID, set_id_expr, sys_id_expr)
Apply get_link_from_by_category() with category described by sys_id_expr
(Section 6.3.3.3), on set set_id_expr and return the answer set. If set_id_expr
is SET_ID(0) then apply query on object the condition is evaluated for.
int GET_LINK_TO_BY_CATEGORY(sessionID, set_id_expr, sys_id_expr)
Apply get_link_to_by_category() with category described by sys_id_expr
(Section 6.3.3.3), on set set_id_expr and return the answer set. If set_id_expr
is SET_ID(0) then apply query on object the condition is evaluated for.
6.3.3.5 An Example
The following code segment finds all instances of current node that have exactly one
link pointing to them:
tmp_set = get_instances(sessionID, 0);
set_filter_cond(sessionID,
EQ(sessionID,
CARD(sessionID,
GET_LINK_TO(sessionID, SET_ID(sessionID,0))),
VAL(sessionID, 1)
)
);
ans_set = get_filtered( sessionID, tmp_set);
6.3.4 General recursive queries
There are queries whose answer requires traversing of links in the SIS base. API has a
query function that starting from an object, traverses links according to some
restrictions. The restrictions have to do with the traversed links and/or the visited
nodes. Actually, the programmer has to define logical expressions, see next section on
how to do so, that are evaluated for each traversed link and visited node: if the
expression is true for some link pointing from the currently visiting node and if the
expression is true for the to-value of the link then this link is traversed forward. In the
same way if the expression is true for some link pointing to the currently visiting node
and if the expression is true for the from-value of the link then this link is traversed
backwards.
The depth of the traverse can be controlled with the set_depth() function. If not
explicitly set, the depth is not controlled.
int get_traverse_by_all_links(int sessionID, int set_id, int isa)
If set_id is 0, starts from the current node and traverses all the links according
to the specified conditions. If conditions have not been explicitly set then all
links are traversed. The isa argument can be any of UPWARDS, DOWNWARDS,
UP_DOWN or NOISA. If UPWARDS is used, then for each node visited on
traversing, all superclasses of this node are visited too. If DOWNWARDS is used,
August 2002/v2.2.2 -27- ICS-FORTH