--- loncom/interface/lonsearchcat.pm	2001/03/15 21:51:21	1.40
+++ loncom/interface/lonsearchcat.pm	2001/03/20 17:49:03	1.44
@@ -2,7 +2,41 @@
 # Search Catalog
 #
 # 03/08/2001 Scott Harrison
+# Scott Harrison: 03/12/2001, 03/13/2001, 03/14/2001, 03/15/2001, 03/19/2001
+# Scott Harrison: 03/20/2001
 #
+# Functions
+#
+# handler(server reference) : interacts with the Apache server layer
+#                             (for /adm/searchcat URLs)
+# simpletextfield(name,value) : returns HTML formatted string for simple text
+#                               field
+# simplecheckbox(name,value) : returns HTML formatted string for simple
+#                              checkbox
+# searchphrasefield(title,name,value) : returns HTML formatted string for
+#                                       a search expression phrase field
+# dateboxes(name, defaultmonth, defaultday, defaultyear) : returns HTML
+#                                                          formatted string
+#                                                          for a calendar date
+# selectbox(title,name,value,%HASH=options) : returns HTML formatted string for
+#                                             a selection box field
+# advancedsearch(server reference, environment reference) : perform a complex
+#                                  multi-field logical query
+# filled(field) : determines whether a given field has been filled
+# basicsearch(server reference, environment reference) : perform a simple
+#                               single-field logical query
+# output_blank_field_error(server reference) : outputs a message saying that
+#                                              more fields need to be filled in
+# output_results(output mode,
+#                server reference, 
+#                environment reference,
+#                reply list reference) : outputs results from search
+# 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;
 
 use strict;
@@ -10,6 +44,7 @@ use Apache::Constants qw(:common);
 use Apache::lonnet();
 use Apache::File();
 use CGI qw(:standard);
+use Text::Query;
 
 my %language;
 my $scrout;
@@ -232,12 +267,6 @@ ENDDOCUMENT
 
 # --------------------------------------------------------- Various form fields
 
-sub textfield {
-    my ($title,$name,$value)=@_;
-    return "\n<p><b>$title:</b><br>".
-           '<input type=text name="'.$name.'" size=80 value="'.$value.'">';
-}
-
 sub simpletextfield {
     my ($name,$value)=@_;
     return '<input type=text name="'.$name.'" size=20 value="'.$value.'">';
@@ -439,13 +468,23 @@ sub advancedsearch {
     }
 
     my $query='';
+
+    my $testquery='';
+    # Go through logical expression AND/OR/NOT phrase fields.
+    foreach my $field ('title','author','subject','notes','abstract') {
+	if ($ENV{'form.'.$field}) {
+	    $testquery=build_SQL_query($field,$ENV{'form.'.$field});
+	}
+    }
+
 #    my $concatarg=join(',"    ",',
 #		       ('title', 'author', 'subject', 'notes', 'abstract'));
 
-    $query="select * from metadata where concat(title) like '\%$ENV{'form.title'}\%'";
+    $query="select * from metadata where $testquery";
+
     my $reply=&Apache::lonnet::metadata_query($query);
 
-    &output_results($r,$envhash,$reply);
+    &output_results('Advanced',$r,$envhash,$query,$reply);
     return OK;
 }
 
@@ -476,10 +515,11 @@ 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,$envhash,$query,$reply);
     return OK;
 }
 
+# ---------------- Message to output when there are not enough fields filled in
 sub output_blank_field_error {
     my ($r)=@_;
     # make query information persistent to allow for subsequent revision
@@ -526,8 +566,10 @@ RESULTS
 
 # ----------------------------- format and output results based on a reply list
 sub output_results {
-    my ($r,$envhash,@replylist)=@_;
+    my ($mode,$r,$envhash,$query,@replylist)=@_;
     my %ENV=%{$envhash};
+    my $compiledresult='';
+
     foreach my $reply (@replylist) {
 
 	my @results;
@@ -550,8 +592,6 @@ sub output_results {
 	    @results=<$fh>;
 	}
 
-	my $compiledresult='';
-
 	foreach my $result (@results) {
 	    my ($title,$author,$subject,$url,$keywords,$version,
 		$notes,$abstract,$mime,$lang,
@@ -641,9 +681,23 @@ 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') {
+	$r->print(<<RESULTS);
+<p>
+<b>Advanced search</b>
+$query
+</p>
+RESULTS
+    }
+	$r->print(<<RESULTS);
 <h3>Search Results</h3>
 $compiledresult
 </body>
@@ -652,5 +706,46 @@ 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');
+    $q->prepare($logic_statement);
+    my $matchexp=${$q}{'matchexp'}; chomp $matchexp;
+    my $sql_query=&recursive_SQL_query_build($field_name,$matchexp);
+    return $sql_query;
+}
+
+# - Recursively parse a reverse notation expression into a SQL query expression
+sub recursive_SQL_query_build {
+    my ($dkey,$pattern)=@_;
+    my @matches=($pattern=~/(\[[^\]|\[]*\])/g);
+    return $pattern unless @matches;
+    foreach my $match (@matches) {
+	$match=~/\[ (\w+)\s(.*) \]/;
+	my ($key,$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;
 __END__