pgr_aDijkstraFromAtoB

CREATE OR REPLACE FUNCTION pgr_aDijkstraFromAtoB(
                IN tbl varchar,
                IN st_x double precision,
                IN st_y double precision,
                IN end_x double precision,
                IN end_y double precision,
                OUT seq integer,
                OUT node integer,
                OUT edge integer,
                OUT heading double precision,
                OUT cost double precision,
                OUT geom geometry
        )
        RETURNS SETOF record AS
$BODY$
DECLARE
        sql     text;
        rec     record;
        source	integer;
        target	integer;
        --point	integer;
        
BEGIN
	-- Find nearest node
	EXECUTE 'SELECT id::integer FROM ways_vertices_pgr 
			ORDER BY the_geom <-> ST_GeometryFromText(''POINT(' 
			|| st_x || ' ' || st_y || ')'',4326) LIMIT 1' INTO rec;
	source := rec.id;
	
	EXECUTE 'SELECT id::integer FROM ways_vertices_pgr 
			ORDER BY the_geom <-> ST_GeometryFromText(''POINT(' 
			|| end_x || ' ' || end_y || ')'',4326) LIMIT 1' INTO rec;
	target := rec.id;
	
	-- Shortest path query (TODO: limit extent by BBOX) 
        seq := 0;
        
        sql := 'SELECT seq, id1 AS node, id2 AS edge, cost, the_geom FROM ' ||
                        'pgr_dijkstra(''SELECT id, source, target, st_length(the_geom) as cost FROM '
                                        || quote_ident(tbl) || ''', '
                                        || source || ', ' || target 
                                        || ' , false, false) as pgr JOIN '
                                || quote_ident(tbl) || ' pt ON pgr.id2 = pt.id';

                               
                        
 
	-- Remember start point
        --point := source;
	
        FOR rec IN EXECUTE sql
        LOOP
		
		-- Return record
                seq     := seq + 1;
                node     := rec.node;
                edge    := rec.edge;
                cost    := rec.cost;
                geom    := rec.the_geom;
           
                RETURN NEXT;
                
        END LOOP;
        RETURN;
	
END;
$BODY$
LANGUAGE 'plpgsql' VOLATILE STRICT;

-- SELECT geom into test2 FROM pgr_aDijkstraFromAtoB('ways', 8.677841, 50.1231, 8.683957, 50.125071)