--- trunk/pgest.c	2005/05/25 23:28:15	11
+++ trunk/pgest.c	2005/05/25 23:38:37	12
@@ -63,19 +63,40 @@
 	if (SRF_IS_FIRSTCALL()) {
 		MemoryContext	oldcontext;
 
-		/* take arguments from function */
-		//index_path = _textout(PG_GETARG_TEXT_P(0));
-		index_path = _textout(PG_GETARG_TEXT_P(0));
-		query = _textout(PG_GETARG_TEXT_P(1));
-		attr = _textout(PG_GETARG_TEXT_P(2));
-		limit = PG_GETARG_INT32(3);
-		offset = PG_GETARG_INT32(4);
-
 		/* create a function context for cross-call persistence */
 		funcctx = SRF_FIRSTCALL_INIT();
 
 		/* switch to memory context appropriate for multiple function calls */
 		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+		/* take arguments from function */
+
+		/* index path */
+		if (PG_ARGISNULL(0)) {
+			elog(ERROR, "index path can't be null");
+			SRF_RETURN_DONE(funcctx);
+		}
+		index_path = _textout(PG_GETARG_TEXT_P(0));
+
+		/* query string */
+		if (PG_ARGISNULL(0)) {
+			query = "";
+		} else {
+			query = _textout(PG_GETARG_TEXT_P(1));
+		}
+
+		/* atribute filter */
+		if (PG_ARGISNULL(2)) {
+			attr = "";
+		} else {
+			attr = _textout(PG_GETARG_TEXT_P(2));
+		}
+
+		/* limit */
+		if (! PG_ARGISNULL(3)) limit = PG_GETARG_INT32(3);
+
+		/* offset */
+		if (! PG_ARGISNULL(4)) offset = PG_GETARG_INT32(4);
+
 
 		/* open the database */
 		elog(DEBUG1, "pgest: est_db_open(%s)", index_path);
@@ -85,7 +106,7 @@
 			SRF_RETURN_DONE(funcctx);
 		}
 		
-		elog(INFO, "pgest: query[%s] attr[%s] limit %d offset %d", query, attr, limit, offset);
+		elog(INFO, "pgest: query[%s] attr[%s] limit %d offset %d", query, (PG_ARGISNULL(2) ? "NULL" : attr), limit, offset);
 		
 		/* create a search condition object */
 		if (!(cond = est_cond_new())) {
@@ -94,11 +115,11 @@
 		}
 		
 		/* set the search phrase to the search condition object */
-		if (strlen(query) > 0)
+		if (! PG_ARGISNULL(1) && strlen(query) > 0)
 			est_cond_set_phrase(cond, query);
 
 		/* minimum valid attribute length is 10: @a STREQ a */
-		if (attr != NULL && strlen(attr) >= 10) {
+		if (! PG_ARGISNULL(2) && strlen(attr) >= 10) {
 			elog(INFO,"est_cond_add_attr(%s)", attr);
 			est_cond_add_attr(cond, attr);
 		}