--- loncom/interface/lonsearchcat.pm	2001/03/20 11:45:21	1.42
+++ loncom/interface/lonsearchcat.pm	2001/03/20 12:21:56	1.43
@@ -31,8 +31,11 @@
 #                server reference, 
 #                environment reference,
 #                reply list reference) : outputs results from search
-# build_SQL_query() : builds a SQL query string from a logical expression
-#                     with AND/OR keywords
+# build_SQL_query(field name, logic) : builds a SQL query string from a
+#                                      logical expression with AND/OR keywords
+# recursive_SQL_query_build(field name, reverse notation expression) : 
+#                 builds a SQL query string from a reverse notation expression
+#                 logical expression with AND/OR keywords
 
 package Apache::lonsearchcat;
 
@@ -471,7 +474,7 @@ sub advancedsearch {
     $query="select * from metadata where concat(title) like '\%$ENV{'form.title'}\%'";
     my $reply=&Apache::lonnet::metadata_query($query);
 
-    &output_results($r,$envhash,$reply);
+    &output_results('Advanced',$r,$envhash,$reply);
     return OK;
 }
 
@@ -502,7 +505,7 @@ sub basicsearch {
 
     $query="select * from metadata where concat($concatarg) like '\%$ENV{'form.basicexp'}\%'";
     my $reply=&Apache::lonnet::metadata_query($query);
-    &output_results($r,$envhash,$reply);
+    &output_results('Basic',$r,$envhash,$reply);
     return OK;
 }
 
@@ -552,7 +555,7 @@ RESULTS
 
 # ----------------------------- format and output results based on a reply list
 sub output_results {
-    my ($r,$envhash,@replylist)=@_;
+    my ($mode,$r,$envhash,@replylist)=@_;
     my %ENV=%{$envhash};
     foreach my $reply (@replylist) {
 
@@ -667,9 +670,20 @@ onClick='self.close();'>
 $persistent
 <hr>
 <h3>Search Query</h3>
+RESULTS
+    if ($mode eq 'Basic') {
+	$r->print(<<RESULTS);
 <p>
 <b>Basic search:</b> $ENV{'form.basicexp'}
 </p>
+RESULTS
+    elsif ($mode eq 'Advanced') {
+	$r->print(<<RESULTS);
+<p>
+<b>Advanced search</b>
+</p>
+RESULTS
+    }
 <h3>Search Results</h3>
 $compiledresult
 </body>
@@ -680,7 +694,42 @@ RESULTS
 
 # ------------------------------------------------------------- build_SQL_query
 sub build_SQL_query {
-
+    my ($field_name,$logic_statement)=@_;
+    my $q=new Text::Query('abc',
+			  -parse => 'Text::Query::ParseAdvanced',
+			  -build => 'Text::Query::Build');
+    $q->prepare($statement);
+    my $matchexp=${$q}{'matchexp'}; chomp $matchexp;
+    my $sql_query=&recursive_SQL_query_build($field_name,$matchexp);
+}
+
+# - Recursively parse a reverse notation expression into a SQL query expression
+sub recursive_SQL_query_build {
+    my ($dkey,$pattern)=@_;
+    my @matches=($pattern=~/(\[[^\]|\[]*\])/g);
+    return $pattern unless @matches;
+    foreach my $match (@matches) {
+	$match=~/\[ (\w+)\s(.*) \]/;
+	($key,$value)=($1,$2);
+	my $replacement='';
+	if ($key eq 'literal') {
+	    $replacement="($dkey like \"\%$value\%\")";
+	}
+	elsif ($key eq 'and') {
+	    $value=~/(.*[\"|\)]) ([|\(|\^].*)/;
+	    $replacement="($1 AND $2)";
+	}
+	elsif ($key eq 'or') {
+	    $value=~/(.*[\"|\)]) ([|\(|\^].*)/;
+	    $replacement="($1 OR $2)";
+	}
+	substr($pattern,
+	       index($pattern,$match),
+	       length($match),
+	       $replacement
+	       );
+    }
+    &recursive_SQL_query_build($dkey,$pattern);
 }
 
 1;