Adding validate function, with no calls

utPLSQL · jgebal · Apr 28, 2023 · Mar 28, 2023 · Mar 28, 2023 · Mar 29, 2023
commit e87d39f992da9ff7fdb0cb2b653f6fc0380c6def
diff --git a/source/core/ut_utils.pkb b/source/core/ut_utils.pkb
@@ -989,6 +989,67 @@ create or replace package body ut_utils is
    return l_result;
  end;

+  function valid_tag_expression(a_tags in varchar2) return number is
+    t_left_side ut_varchar2_list := ut_varchar2_list('|','&',',');
+    t_right_side  ut_varchar2_list := ut_varchar2_list('!','-');
+    l_left_side_expression varchar2(100) := '[|&,]';
+    l_left_side_regex varchar(400) := '([^|&,]*)[|&,](.*)';    
+    l_left_side varchar2(4000);
+
+    l_rigth_side_expression varchar2(100) := '[!-]';    
+    l_right_side_regex varchar(400) := '([!-])([^!-].*)';
+    l_right_side varchar2(4000);
+
+    l_tags varchar2(4000) := a_tags;
+    l_result number :=1;
+  begin
+    --Validate that we have closed up all brackets
+    if regexp_count(l_tags,'\(') <> regexp_count(l_tags,'\)') then
+      l_result := 0;
+    end if;
+
+    --Remove brackets as we dont evaluate expression only validate.
+    l_tags := replace(replace(l_tags,'('),')');
+
+    --Check if there are any left side operators for first in order from left to right
+    if regexp_count(l_tags,l_left_side_expression) > 0 then
+      --Extract left part of operator and remaining of string to right
+      l_left_side := regexp_replace(l_tags,l_left_side_regex,'\1');
+      l_right_side := regexp_replace(l_tags,l_left_side_regex,'\2');
+
+      --If left side is null that means that we used left side operator without 
+      -- left and right e.g. &test
+      if l_left_side is null then 
+        l_result := 0;
+      else
+      --Extract right side from left side expression if there is any !-
+      --Remove first negation tag to see if there is double negation
+        l_left_side := regexp_replace(l_left_side,l_right_side_regex,'\2');
+      end if;
+
+
+      --check that on right side there is no extra negation   
+      if regexp_count(l_left_side,l_rigth_side_expression) > 0 then
+        l_result := 0;
+      end if;
+
+      --Now process right side of string
+      if l_right_side is not null then
+        l_result := least(l_result,valid_tag_expression(l_right_side));
+      else
+        l_result := 0;
+      end if;
+    else
+      --We just process single tag.
+      l_left_side := l_tags;
+      l_left_side := regexp_replace(l_left_side,l_right_side_regex,'\2'); 
+      if regexp_count(l_left_side,l_rigth_side_expression) > 0 then
+        l_result := 0;
+      end if; 
+    end if;
+
+    return l_result;
+  end;

 end ut_utils;
 /
diff --git a/source/core/ut_utils.pks b/source/core/ut_utils.pks
@@ -476,6 +476,11 @@ create or replace package ut_utils authid definer is
  * Return value of interval in plain english
  */    
  function interval_to_text(a_interval yminterval_unconstrained) return varchar2;
-
+
+  /*
+  * Return number 1 or 0 if the list of tags is valid expression
+  */   
+  function valid_tag_expression(a_tags in varchar2) return number;
+
 end ut_utils;
 /