--- loncom/html/adm/helper/newslot.helper	2017/06/23 20:14:36	1.30.2.1
+++ loncom/html/adm/helper/newslot.helper	2023/07/07 04:18:18	1.30.4.1.4.2
@@ -208,11 +208,34 @@
         delete($helper->{'VARS'}{'startreserve'});
         delete($helper->{'VARS'}{'endreserve'});
         delete($helper->{'VARS'}{'maxspace'});
-        delete($helper->{'VARS'}{'startunique'});
-        delete($helper->{'VARS'}{'endunique'});
       </exec>
+      <message>
+         </p><p>Period of time when this slot can only be uniquely assigned:<br />&nbsp;&nbsp;&nbsp;Start:
+      </message>
+      <date variable="startunique" hoursminutes="1" anytime="1">
+        <defaultvalue>
+          my $default=&{$helper->{DATA}{origslot}}('uniqueperiod','anytime');
+          if ($default eq 'anytime') { return 'anytime' };
+          if (ref($default)) { return $default->[0]; }
+          return 'anytime';
+        </defaultvalue>
+      </date>
+      <message><br />&nbsp;&nbsp;&nbsp;End: </message>
+      <date variable="endunique" hoursminutes="1" anytime="1">
+        <defaultvalue>
+          my $default=&{$helper->{DATA}{origslot}}('uniqueperiod','anytime');
+          if ($default eq 'anytime') { return 'anytime' };
+          if (ref($default)) { return $default->[1]; }
+          return 'anytime';
+        </defaultvalue>
+        <validator>
+           if (defined($val) && $val < $helper->{'VARS'}{'startunique'}) {
+               return 'End time must be later than the start time.';
+           }
+           return undef;
+        </validator>
+      </date>
     </condition>
-
     <message>
       </p><p>Proctored access:
     </message>
@@ -251,9 +274,9 @@
         return 'any';
       </defaultvalue>
     </choices>
-    
+
     <message>
-	</p><p>IP restrictions -- allow from all except:<br />&nbsp;&nbsp;&nbsp;      
+      </p><p>IP restrictions -- allow from all except: <br />&nbsp;&nbsp;&nbsp;
     </message>
 
     <string variable="ipdeny" size="30">
@@ -286,7 +309,7 @@
     <nextstate>PROCTOR</nextstate>
 
     <resource variable="symb">
-      <filterfunc>return $res->is_problem()</filterfunc>
+      <filterfunc>return $res->is_problem() || $res->is_tool()</filterfunc>
       <valuefunc>return $res->symb()</valuefunc>
       <defaultvalue>
         return &{$helper->{DATA}{origslot}}('symb');