gis.road_graph

Parameters

Name	Type	Mode
		IN

Definition

DECLARE
    edge_under_node record;
    id_new_edge integer;
    raise_notice text;
    is_edge_extremity boolean;
    attached_edge_ids integer[];
BEGIN
    -- Trigger disabled by session variable
    IF road_graph.get_current_setting('road.graph.disable.trigger', '0') = '1'
    THEN
        RETURN NEW;
    END IF;

-- Check if we must log
    raise_notice = road_graph.get_current_setting('road.graph.raise.notice', 'no');

-- Check if the node is the start or end node of an edge being created or moved
    -- (see before_edge_insert_or_update and after_edge_insert_or_update)
    -- The variable is reset at once, so that it is not used by the cascading changes
    is_edge_extremity = (road_graph.get_current_setting('road.graph.node.edge.extremity', 'no') = 'yes');
    SET LOCAL road.graph.node.edge.extremity = 'no';

-- Do nothing if geometry has not changed
    -- except road.graph.edge.update.touching.node equals yes
    IF
        TG_OP = 'UPDATE'
        AND ST_Equals(NEW.geom, OLD.geom)
        AND road_graph.get_current_setting('road.graph.edge.update.touching.node', 'no') = 'no'
    THEN
        IF raise_notice IN ('info', 'debug') THEN
            RAISE NOTICE '% AFTER node % n° %, OLD & NEW geometries are equal, return',
                repeat('    ', pg_trigger_depth()::integer), TG_OP, NEW.id
            ;
        END IF;
        RETURN NEW;
    END IF;

-- Update all upstream edges referenced ids.
    -- The edges of another node less than 50 cm from this node are attached to this node:
    -- the two nodes are merged. The ids of the attached edges are kept
    WITH attached AS (
        UPDATE road_graph.edges AS t
        SET start_node = NEW.id
        WHERE ST_DWithin(NEW.geom, ST_StartPoint(t.geom), 0.50)
        AND start_node != NEW.id
        RETURNING t.id
    )
    SELECT array_agg(a.id)
    INTO attached_edge_ids
    FROM attached AS a
    ;

-- Update all downstream edges referenced ids
    WITH attached AS (
        UPDATE road_graph.edges AS t
        SET end_node = NEW.id
        WHERE ST_DWithin(NEW.geom, ST_EndPoint(t.geom), 0.50)
        AND end_node != NEW.id
        RETURNING t.id
    )
    SELECT Coalesce(attached_edge_ids, '{}') || Coalesce(array_agg(a.id), '{}')
    INTO attached_edge_ids
    FROM attached AS a
    ;

-- Update geometry of all upstream edges linked to the node
    -- We replace the first edge node by the node NEW geometry
    -- We deactivate the creation of crossing nodes for these updated edges
    SET LOCAL road.graph.edge.crossing.node.creation.pending = 'yes';
    UPDATE road_graph.edges AS t
    SET geom = ST_SetPoint(geom, 0, NEW.geom)
    WHERE TRUE
    AND start_node = NEW.id
    AND NOT ST_Intersects(ST_StartPoint(geom), NEW.geom)
    ;
    SET LOCAL road.graph.edge.crossing.node.creation.pending = 'no';

-- Update geometry of all downstream edges linked to the node
    -- We replace the last edge node but the node NEW geometry
    -- We deactivate the creation of crossing nodes for these updated edges
    SET LOCAL road.graph.edge.crossing.node.creation.pending = 'yes';
    UPDATE road_graph.edges AS t
    SET geom = ST_SetPoint(geom, ST_NPoints(geom) - 1, NEW.geom)
    WHERE True
    AND end_node = NEW.id
    AND NOT ST_Intersects(ST_EndPoint(geom), NEW.geom)
    ;
    SET LOCAL road.graph.edge.crossing.node.creation.pending = 'no';

-- Delete the edges which now start and end at this node, and did not before:
    -- for example the edge between this node and the merged node
    IF cardinality(attached_edge_ids) > 0 THEN
        DELETE FROM road_graph.edges AS t
        WHERE t.id = ANY(attached_edge_ids)
        AND t.start_node = NEW.id
        AND t.end_node = NEW.id
        ;
    END IF;

-- Split edges under the node if needed
    FOR edge_under_node IN
        SELECT
            -- we must pass all the fields
            -- to be able to copy/paste attributes data from the original edge
            -- when spliting it
            t.*
        FROM road_graph.edges AS t
        WHERE True
        -- Do not split the edges having the value True in no_intersection_cutting,
        -- except if the node is the extremity of an edge being created or moved
        -- (for example a new access road arriving in the middle of a highway edge)
        AND (
            NOT Coalesce(t.no_intersection_cutting, False)
            OR is_edge_extremity
        )
        -- edge is close to the node
        AND ST_DWithin(t.geom, NEW.geom, 0.50)
        -- but node is far enough from the start and end points
        AND NOT ST_DWithin(ST_StartPoint(t.geom), NEW.geom, 0.50)
        AND NOT ST_DWithin(ST_EndPoint(t.geom), NEW.geom, 0.50)
        ORDER BY t.geom <-> NEW.geom
    LOOP
        IF edge_under_node.id IS NOT NULL THEN
            IF raise_notice IN ('info', 'debug') THEN
                RAISE NOTICE '% AFTER NODE % n° % %, found nearby edge % -> should split it',
                    repeat('    ', pg_trigger_depth()::integer), TG_OP, NEW.id, ST_AsText(NEW.geom), edge_under_node.id
                ;
            END IF;
            IF raise_notice IN ('debug') THEN
                RAISE NOTICE 'EDGE TO BE SPLIT';
                RAISE NOTICE '%', to_json(edge_under_node);
            END IF;

SELECT INTO id_new_edge
                split_edge_by_node
            FROM road_graph.split_edge_by_node(
                -- edge
                edge_under_node,
                -- node
                NEW,
                -- minimum distance from line
                0.50::real,
                -- maximum distance from start & end points
                0.50::real
            );

IF raise_notice IN ('info', 'debug') THEN
                RAISE NOTICE '% AFTER NODE % n° % %, New edge created from split: %',
                    repeat('    ', pg_trigger_depth()::integer), TG_OP, NEW.id, ST_AsText(NEW.geom), id_new_edge
                ;
            END IF;
        END IF;
    END LOOP;

RETURN NEW;
END;

after_node_insert_or_update()

Description

Parameters

Definition