--- loncom/homework/chemresponse.pm	2003/05/05 20:43:46	1.4
+++ loncom/homework/chemresponse.pm	2025/01/27 18:43:23	1.103
@@ -1,7 +1,7 @@
 # The LearningOnline Network with CAPA
 # chemical equation style response
 #
-# $Id: chemresponse.pm,v 1.4 2003/05/05 20:43:46 albertel Exp $
+# $Id: chemresponse.pm,v 1.103 2025/01/27 18:43:23 raeburn Exp $
 #
 # Copyright Michigan State University Board of Trustees
 #
@@ -30,182 +30,605 @@ package Apache::chemresponse;
 use strict;
 use Apache::lonxml;
 use Apache::lonnet;
+use Apache::lonlocal;
+use lib '/home/httpd/lib/perl/';
+use LONCAPA;
+ 
 
 BEGIN {
-    &Apache::lonxml::register('Apache::chemresponse',('chemresponse','chemstructure','reactionresponse'));
+    &Apache::lonxml::register('Apache::chemresponse',('organicresponse','organicstructure','reactionresponse','chem'));
 }
 
-sub seperate_jme_window {
-    my ($smile_input,$jme_input,$molecule)=@_;
+sub chem_standard_order {
+    my ($reaction) = @_;
+    my ($re,$pr) = split(/->|<=>/,$reaction);
+    my @reactants = split(/\s\+/,$re);
+    my @products =  split(/\s\+/,$pr);
+    foreach my $substance (@reactants,@products) {
+	$substance =~ s/(\^\d*)\s+/$1_/g;         # protect superscript space
+	$substance =~ s/\s*//g;                   # strip whitespace
+	$substance =~ s/_/ /g;                    # restore superscript space
+    }
+    @reactants = sort @reactants;
+    @products = sort @products;
+    my $standard = '';
+    foreach my $substance (@reactants) {
+	$standard .= $substance;
+	$standard .= ' + ';
+    }
+    $standard =~ s/ \+ $//;              # get rid of trailing plus sign
+    $standard .= ' -> ';
+    foreach my $substance (@products) {
+	$standard .= $substance;
+	$standard .= ' + ';
+    }
+    $standard =~ s/ \+ $//;              # get rid of trailing plus sign
+    return $standard;
+}
+
+sub separate_jme_window {
+    my ($smile_input,$jme_input,$molecule,$options,$shown_text)=@_;
+    my $usejsme = 1;
+    if (($env{'request.course.id'}) && ($env{'request.state'} ne 'construct')) {
+        if (exists($env{'course.'.$env{'request.course.id'}.'.usejsme'})) {
+            if ($env{'course.'.$env{'request.course.id'}.'.usejsme'} eq '0') {
+                $usejsme = 0;
+            }
+        } else {
+            my %domdefs = &Apache::lonnet::get_domain_defaults($env{'course.'.$env{'request.course.id'}.'.domain'});
+            if ($domdefs{'usejsme'} eq '0') {
+                $usejsme = 0;
+            }
+        }
+    } else {
+        my %domdefs = &Apache::lonnet::get_domain_defaults($env{'course.'.$env{'request.course.id'}.'.domain'});
+        if ($domdefs{'usejsme'} eq '0') {
+            $usejsme = 0;
+        }
+    }
+    if ($usejsme) {
+        if ($env{'browser.type'} eq 'safari') {
+            unless ($env{'browser.mobile'}) {
+                if ($env{'browser.version'} < 534) {
+                    $usejsme = 0;
+                }
+            }
+        } elsif ($env{'browser.type'} eq 'mozilla') {
+            if ($env{'browser.version'} < 5) {
+                $usejsme = 0;
+            } elsif ($env{'browser.info'} =~ /^firefox\-([\d\.]+)/) {
+                my $firefox = $1;
+                if ($firefox < 12) {
+                    $usejsme = 0;
+                }
+            }
+        } elsif ($env{'browser.type'} eq 'explorer') {
+            if ($env{'browser.version'} < 7) {
+                $usejsme = 0;
+            }
+        } elsif ($env{'browser.type'} eq 'opera') {
+            if ($env{'browser.version'} < 15) {
+                $usejsme = 0;
+            }
+        }
+    } else {
+        if ($env{'browser.mobile'}) {
+            $usejsme = 1;
+        }
+    }
+    my $linkstyle = 'display:none';
+    my $creditstyle = 'display:inline';
+    if ($env{'browser.type'} eq 'explorer') {
+        if (($env{'browser.os'} eq 'win') && ($env{'browser.version'} < 9)) {
+            $linkstyle = 'display:inline';
+            $creditstyle = 'display:none';
+        }
+    }
     my $smilesection;
     if (defined($smile_input)) {
+        my $smiles;
+        if ($usejsme) {
+            $smiles = 'document.JME.smiles()'; 
+        } else {
+            $smiles = 'document.applets.JME.smiles()';
+        }
 	$smilesection=<<SMILESECTION;
-	opener.document.lonhomework.$smile_input.value = smiles;
+	opener.document.lonhomework.$smile_input.value = $smiles;
 SMILESECTION
     }
     my $jmesection;
+    my $jmefile;
     if (defined($jme_input)) {
+        if ($usejsme) {
+            $jmefile = 'document.JME.jmeFile()';
+        } else {
+            $jmefile = 'document.applets.JME.jmeFile()';
+        }
 	$jmesection=<<JMESECTION;
-	jmeFile = document.applets.JME.jmeFile();
-	opener.document.lonhomework.$jme_input.value = jmeFile;
+	opener.document.lonhomework.$jme_input.value = $jmefile;
 JMESECTION
     }
 
-    my $body=<<CHEMPAGE;
-<html>
-<head>
-<title>Molecule Editor</title>
-<script language="JavaScript">
+    if ($molecule) {
+        if ($usejsme) {
+            $molecule = 'document.JME.readMolecule("'.$molecule.'")';
+        } else {
+            $molecule='<param name="jme" value="'.$molecule.'" />';
+        }
+    }
+    my $insert_answer;
+    if ($shown_text eq '') { 
+	$insert_answer=
+	    '<input type="button" name="submit" value="'.&mt('Insert Answer').'" onclick="javascript:submitSmiles();" /><br />';
+    }
+
+   
+
+    my ($jsme_js,$js,$buttonstyle,$viewportjs,$resizejs);
+    if ($usejsme) {
+        $buttonstyle = 'display:none';
+        $resizejs =<<RESIZEJS;
+<script type="text/javascript">
+function callResize() {
+    var timer;
+    clearTimeout(timer);
+    timer=setTimeout('resize_jsme()',100);
+}
+
+window.onresize = callResize;
+
+function resize_jsme() {
+    init_geometry();
+    var vph = Geometry.getViewportHeight();
+    var vpw = Geometry.getViewportWidth();
+    var lowerdivheight = document.getElementById('JMEbuttons').offsetHeight;
+    var formheight = document.getElementById('JMEform').offsetHeight;
+    var freevspace = vph-(lowerdivheight+50);
+    var freehspace = vpw-20;
+    if (typeof jsmeApplet !== 'undefined') {
+        jsmeApplet.setSize(freehspace,freevspace);
+    }
+}
+</script>
+RESIZEJS
+        $resizejs = &Apache::loncommon::js_ready($resizejs);
+        $jsme_js = '
+<script type="text/javascript" language="javascript" src="/adm/jsme/jsme.nocache.js"></script>'."\n";
+        $js =<<CHEMJS;
+<script type="text/javascript">
+function jsmeOnLoad() {
+    document.getElementById('JMErefresh').style.display="none";
+    document.getElementById('JMEcredits').style.display="inline";
+    jsmeApplet = new JSApplet.JSME("jme", "420px", "330px", {"options" : "$options"});
+    document.JME = jsmeApplet;
+    $molecule;
+    document.getElementById('JMEbuttons').style.display="block";
+    callResize();
+}
+
 function submitSmiles() {
-    smiles = document.applets.JME.smiles();
-    if (smiles == "") {
-	alert("Nothing to submit");
+    jmeFile = document.JME.jmeFile();
+    if (jmeFile == "") {
+        alert("Nothing to submit");
     } else {
+        $jmesection
         $smilesection
+        window.close();
+    }
+}
+function openHelpWindow() {
+    window.open("https://jsme-editor.github.io/help.html","","scrollbars=yes,resizable=yes,width=500,height=600");
+}
+
+</script>
+
+CHEMJS
+
+        $viewportjs = &Apache::loncommon::viewport_geometry_js();
+        $viewportjs = '<script type="text/javascript">'."\n".
+                      $viewportjs."\n".
+                      '</script>';
+
+    } else {
+        $buttonstyle = 'display:block';
+        $js =<<CHEMJS; 
+<script type="text/javascript">
+function submitSmiles() {
+    jmeFile = document.applets.JME.jmeFile();
+    if (jmeFile == "") {
+	alert("Nothing to submit");
+    } else {
         $jmesection
+        $smilesection
 	window.close();
     }
 }
 function openHelpWindow() {
     window.open("/adm/jme/jme_help.html","","scrollbars=yes,resizable=yes,width=500,height=600");
 }
+function substituent(r) {document.applets.JME.setSubstituent(r);}
 </script>
-</head>
-<body bgcolor="#ffffff">
+CHEMJS
+    }
+
+    my $start_page = 
+        &Apache::loncommon::start_page('Molecule Editor',$viewportjs,
+				       {'only_body' => 1,
+					'js_ready'  => 1,
+					'bgcolor'   => '#FFFFFF',});
+    my $end_page =
+ 	&Apache::loncommon::end_page({'js_ready' => 1,});
+    my $java_not_enabled=&Apache::lonhtmlcommon::java_not_enabled();
+    my %lt = &Apache::lonlocal::texthash(
+        'seltext' => 'Select substituent...',
+        'close'   => 'Close',
+        'help'    => 'Help',
+       );
+    my $body = "
+$jsme_js
+$js".'
 <center>
-<applet code="JME.class" name="JME" archive="/adm/jme/JME.jar" width="97%" height="78%">
-You have to enable Java and JavaScript on your machine.
-<param name="jme" value="$molecule" />
-</applet><br />
-<font face="arial,helvetica,sans-serif" size=-1><a href="http://www.molinspiration.com/jme/index.html">JME Editor</a> courtesy of Peter Ertl, Novartis</font>
-<form>
-<input type="button" name="submit" value="Insert Answer" onClick = "submitSmiles();" />
+<form action="" id="JMEform">
+';
+    if ($usejsme) {
+        $body.= <<"ENDCHEM";
+<div id="jme">
+<div id="JMEcredits" style="$creditstyle">
+<span style="font-size:small; font-family:arial,sans-serif;"><a href="http://peter-ertl.com/jsme/">JSME Molecular Editor</a> courtesy of Peter Ertl (Novartis) and Bruno Bienfait</span></div>
+</div>
+ENDCHEM
+    } else {
+        $body.=<<CHEMPAGE;
+  <table width="440"><tr>
+    <td></td>
+    <td align="right">
+      <select onchange="javascript:substituent(options[selectedIndex].text)">
+        <option>$lt{'seltext'}</option>
+        <option>-C(=O)OH</option>
+        <option>-C(=O)OMe</option>
+        <option>-OC(=O)Me</option>
+        <option>-CMe3</option>
+        <option>-CF3</option>
+        <option>-CCl3</option>
+        <option>-NO2</option>
+        <option>-SO2-NH2</option>
+        <option>-NH-SO2-Me</option>
+        <option>-NMe2</option>
+        <option>-C#N</option>
+        <option>-C#C-Me</option>
+        <option>-C#CH</option>
+      </select>
+    </td></tr>
+  </table>
+<applet code="JME.class" name="JME" archive="/adm/jme/JME.jar" width="440" height="390" mayscript>
+$java_not_enabled
+$molecule
+<param name="options" value="$options" />
+</applet>
 <br />
-<input type="button" value="  Close  " onClick = "window.close()" />
+<font face="arial,helvetica,sans-serif" size="-1"><a href="http://www.molinspiration.com/jme/index.html">JME Editor</a> courtesy of Peter Ertl, Novartis</font>
+CHEMPAGE
+    }
+    $body .= <<CHEMPAGE;
+<div id="JMEbuttons" style="$buttonstyle">
+$insert_answer
+<input type="button" value="$lt{'close'}" onclick="javascript:window.close()" />
 &nbsp;&nbsp;
-<input type="button" value="  Help  " onClick = "openHelpWindow()" />
+<input type="button" value="$lt{'help'}" onclick="javascript:openHelpWindow()" />
+</div>
+<div id="JMErefresh" style="$linkstyle">
+<a href="javascript:location.reload();">Display Molecule Editor</a>
+</div> 
 </form>
 </center>
-</body>
-</html>
 CHEMPAGE
-    $body=&HTML::Entities::encode($body);
-    $body=~s/\n/ /g;
+
+    $body=&Apache::loncommon::js_ready($body);
+    my $nothing=&Apache::lonhtmlcommon::javascript_nothing();
+    my $docopen=&Apache::lonhtmlcommon::javascript_docopen();
+    my $display=&mt('Draw Molecule');
+    if (defined($shown_text)) { $display=&mt($shown_text); }
+    my $iconpath=$Apache::lonnet::perlvar{'lonIconsURL'};
+    my $function =
+	'LONCAPA_draw_molecule_'.&get_uniq_name();
     my $result=<<CHEMINPUT;
-<input type="button" value="Draw Molecule" onClick="javascript:editor=window.open('','','width=500,height=500,scrollbars=no,resizable=yes');editor.document.open('text/html','replace');editor.document.writeln('$body')" />
+<script type="text/javascript">
+    function $function() {
+	editor=window.open($nothing,'jmeedit','width=500,height=500,menubar=no,scrollbars=no,resizable=yes');
+        if (editor) {
+	    editor.$docopen;
+	    editor.document.write('$start_page $body $resizejs $end_page');
+	    editor.document.close();
+	    editor.focus();
+        }
+    }
+</script>
 CHEMINPUT
+    my $jscall = "javascript:$function();void(0);";
+    if ($shown_text eq '') {
+        $result .=<<PENCIL;
+<a href="$jscall"><img class="stift" src="$iconpath/stift.gif" alt="$display" title="$display" /></a>
+PENCIL
+    } else {
+        $result .= '<input type="button" value="'.&mt($shown_text).'" onclick="$jscall" />';
+    }
+    return $result;
+}
+sub jme_img {
+    my ($jme,$smile,$width,$options)=@_;
+    my $id=&Apache::loncommon::get_cgi_id();
+    my $result='<img alt="'.$smile.'" src="/cgi-bin/convertjme.pl?'.$id.'"';
+    if ($options =~ /border/) { $result.= ' border="1"'; }
+    $result.=' />';
+    &Apache::lonnet::appenv({'cgi.'.$id.'.JME'   =>
+			     &escape($jme),
+			     'cgi.'.$id.'.PNG'   => 1,
+			     'cgi.'.$id.'.WIDTH' => $width});
     return $result;
 }
 
-sub start_chemresponse {
+sub start_organicresponse {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result;
     my $partid = $Apache::inputtags::part;
     my $id = &Apache::response::start_response($parstack,$safeeval);
     if ($target eq 'meta') {
+	$result=&Apache::response::meta_package_write('organicresponse');
     } elsif ($target eq 'web') {
-	my $molecule;
-	if (defined($Apache::lonhomework::history{"resource.$partid.$id.molecule"})) {
-	    $molecule=$Apache::lonhomework::history{"resource.$partid.$id.molecule"};
-	} else {
-	    $molecule=&Apache::lonxml::get_param('molecule',$parstack,
+	my $jmeanswer=&Apache::lonxml::get_param('jmeanswer',$parstack,
 						 $safeeval);
+	if (&Apache::response::show_answer()) {
+            my $jmeanswer=&Apache::lonxml::get_param('jmeanswer',$parstack,
+                                                     $safeeval);
+            if ($jmeanswer ne '') {
+	        my $options=&Apache::lonxml::get_param('options',$parstack,
+	    					       $safeeval);
+	        my $width=&Apache::lonxml::get_param('width',$parstack,
+						     $safeeval);
+	        my (@answers)=&Apache::lonxml::get_param_var('answer',$parstack,
+							     $safeeval);
+	        $result.=&jme_img($jmeanswer,$answers[0],$width,$options);
+            }
+	} else {
+	    $result.= '<input type="hidden" name="MOLECULE_'.$id.'" value="" />';
 	}
-	$result=&seperate_jme_window("HWVAL_$id","MOLECULE_$id",$molecule);
-	$result.= '<input type="hidden" name="MOLECULE_'.$id.'" value="" />';
     } elsif ($target eq 'edit') {
 	$result .=&Apache::edit::tag_start($target,$token);
-	$result .=&Apache::edit::text_arg('Starting Molecule:','molecule',
-					  $token,40);
+	my $options=&Apache::lonxml::get_param('options',$parstack,
+					       $safeeval);
+	if ($options !~ /multipart/) { $options.=',multipart'; }
+	$result .='<span class="LC_nobreak">'.
+	    &Apache::edit::text_arg('Starting Molecule:','molecule',
+				    $token,40);
 	my $molecule=&Apache::lonxml::get_param('molecule',$parstack,
 						$safeeval);
-	$result .=&seperate_jme_window(undef,
+	$result .=&separate_jme_window(undef,
 		      &Apache::edit::html_element_name('molecule'),
-		      $molecule);
-	$result .='<br />';
+		      $molecule,$options);
+	$result .='</span><br /><span class="LC_nobreak">';
 	$result .=&Apache::edit::text_arg('Correct Answer:','answer',
 					  $token,40);
-	$result .=&Apache::edit::hidden_arg('jmeanswer',$token);
+	$result .='</span><br /><span class="LC_nobreak">';
+	$result .=&Apache::edit::text_arg('JME string of the answer - automatically updated by "Insert Answer" in the JME pop-up (click pencil):',
+					  'jmeanswer',$token);
 	my $jmeanswer=&Apache::lonxml::get_param('jmeanswer',$parstack,
 						 $safeeval);
-	$result .=&seperate_jme_window(
+	$result .=&separate_jme_window(
                       &Apache::edit::html_element_name('answer'),
                       &Apache::edit::html_element_name('jmeanswer'),
-		      $jmeanswer);
+		      $jmeanswer,$options);
+	$result .='</span><br />';
+	$result .=&Apache::edit::checked_arg('Options:','options',
+				    [ ['autoez','Auto E,Z stereochemistry'],
+				      ['multipart','Multipart Structures'],
+				      ['nostereo','No stereochemistry'],
+				      ['reaction','Is a reaction'],
+				      ['number','Able to number atoms'] ],
+					     ,$token);
+	$result .=&Apache::edit::text_arg('Width of correct answer image:',
+					  'width',$token,10);
 	$result .=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
     } elsif ($target eq 'modified') {
 	my $constructtag=&Apache::edit::get_new_args($token,$parstack,
 						     $safeeval,'molecule',
-						     'answer','jmeanswer');
+						     'answer','jmeanswer',
+						     'options','width');
 	if ($constructtag) { $result = &Apache::edit::rebuild_tag($token); }
     }
+
     return $result;
 }
 
-sub end_chemresponse {
+sub end_organicresponse {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result;
-    if ($target eq 'grade' && defined($ENV{'form.submitted'})) {
-	&Apache::response::setup_params($$tagstack[-1]);
+
+    my $partid = $Apache::inputtags::part;
+    my $id = $Apache::inputtags::response['-1'];
+
+    if ($target eq 'grade' 
+	&& &Apache::response::submitted()
+	&& $Apache::lonhomework::type eq 'exam') {
+
+	&Apache::response::scored_response($partid,$id);
+
+    } elsif ($target eq 'grade' 
+	&& &Apache::response::submitted()
+	&& $Apache::lonhomework::type ne 'exam') {
+
+	&Apache::response::setup_params($$tagstack[-1],$safeeval);
 	my $response = &Apache::response::getresponse();
 	if ( $response =~ /[^\s]/) {
-	    my $partid = $Apache::inputtags::part;
-	    my $id = $Apache::inputtags::response['-1'];
-	    my $answer=&Apache::lonxml::get_param('answer',$parstack,$safeeval);
+	    my (@answers)=&Apache::lonxml::get_param_var('answer',$parstack,$safeeval);
 	    my %previous = &Apache::response::check_for_previous($response,$partid,$id);
 	    $Apache::lonhomework::results{"resource.$partid.$id.submission"}=$response;
-	    &Apache::lonxml::debug("submitted a $response for $answer<br \>\n");
 	    my $ad;
-	    if ($response eq $answer) {
-		$ad='EXACT_ANS';
-	    } else {
-		$ad='INCORRECT';
+	    foreach my $answer (@answers) {
+		&Apache::lonxml::debug("submitted a $response for $answer<br \>\n");
+		if ($response eq $answer) {
+		    $ad='EXACT_ANS';
+		    last;
+		} else {
+		    $ad='INCORRECT';
+		}
 	    }
+            if ($ad) {
+	        if ($Apache::lonhomework::type eq 'survey') {
+		    $ad='SUBMITTED';
+                } elsif ($Apache::lonhomework::type eq 'surveycred') {
+                    $ad='SUBMITTED_CREDIT';
+                } elsif ($Apache::lonhomework::type eq 'anonsurvey') {
+                    $ad='ANONYMOUS';
+                } elsif ($Apache::lonhomework::type eq 'anonsurveycred') {
+                    $ad='ANONYMOUS_CREDIT';
+                }
+            }
 	    &Apache::response::handle_previous(\%previous,$ad);
 	    $Apache::lonhomework::results{"resource.$partid.$id.awarddetail"}=$ad;
-	    $Apache::lonhomework::results{"resource.$partid.$id.molecule"}=$ENV{"form.MOLECULE_$id"};
+	    $Apache::lonhomework::results{"resource.$partid.$id.molecule"}=$env{"form.MOLECULE_$id"};
 	}
     } elsif ($target eq "edit") {
 	$result.= &Apache::edit::tag_end($target,$token,'');
+    } elsif ($target eq 'answer') {
+	my (@answers)=&Apache::lonxml::get_param_var('answer',$parstack,
+						     $safeeval);
+	$result.=&Apache::response::answer_header('organicresponse');
+	foreach my $answer (@answers) {
+	    $result.=&Apache::response::answer_part('organicresponse',$answer);
+	}
+	$result.=&Apache::response::answer_footer('organicresponse');
+    }
+    if ($target eq 'web') {
+	&Apache::response::setup_prior_tries_hash(\&format_prior_answer_organic,
+						  ['molecule'])
+    }
+
+    if ($target eq 'grade' || $target eq 'web' || $target eq 'answer' || 
+	$target eq 'tex' || $target eq 'analyze') {
+        my $repetition = &Apache::response::repetition();
+	&Apache::lonxml::increment_counter($repetition,"$partid.$id"); # part.response
+	if ($target eq 'analyze') {
+            $Apache::lonhomework::analyze{"$partid.$id.type"} = 'organicresponse';
+            push (@{ $Apache::lonhomework::analyze{"parts"} },"$partid.$id");
+	    &Apache::lonhomework::set_bubble_lines();
+	}
+    }
+    if ($target eq 'web' ) {
+        my ($showpencil,$shown_text);
+        if ($Apache::inputtags::status['-1'] eq 'CAN_ANSWER') {
+            $showpencil = 1;
+        } elsif (&Apache::response::show_answer()) {
+            my $jmeanswer=&Apache::lonxml::get_param('jmeanswer',$parstack,                                                         $safeeval);
+            if ($jmeanswer eq '') {
+                $showpencil = 1;
+                $shown_text="Show Your Last Answer";
+            }
+        }
+        if ($showpencil) {
+            my $options=&Apache::lonxml::get_param('options',$parstack,
+                                                   $safeeval);
+
+	    my $molecule;
+	    if (defined($Apache::lonhomework::history{"resource.$partid.$id.molecule"})) {
+		$molecule=$Apache::lonhomework::history{"resource.$partid.$id.molecule"};
+	    } else {
+		$molecule=&Apache::lonxml::get_param('molecule',$parstack,
+						     $safeeval);
+	    }
+	    $result.=&separate_jme_window("HWVAL_$id","MOLECULE_$id",$molecule,
+                                          $options,$shown_text);
+        }
     }
-    &Apache::response::end_response;
+    &Apache::response::end_response();
     return $result;
 }
 
-sub start_chemstructure {
+sub format_prior_answer_organic {
+    my ($mode,$answer,$other_data) = @_;
+    my $result=&mt('Smile representation: [_1]','"<tt>'.$answer.'</tt>"');
+    my $jme=$other_data->[0];
+    $result.=&jme_img($jme,$answer,400);
+    return $result;
+}
+
+sub start_organicstructure {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result;
     if ($target eq 'web') {
 	my $width=&Apache::lonxml::get_param('width',$parstack,$safeeval);
-	my $height=&Apache::lonxml::get_param('height',$parstack,$safeeval);
 	my $molecule=&Apache::lonxml::get_param('molecule',$parstack,$safeeval);
-	$result=<<CHEMOUTPUT;
-<applet code="JME.class" archive="/adm/jme/JME.jar" width="$width" height="$height">
-<param name="options" value="depict border" />
-<param name="jme" value="$molecule" />
-</applet>
-CHEMOUTPUT
+	my $options=&Apache::lonxml::get_param('options',$parstack,$safeeval);
+        my $alttext=&Apache::lonxml::get_param('alt',$parstack,$safeeval);
+        if ($alttext eq '') {
+            $alttext = &mt('Organic structure');
+        }
+        $alttext = &HTML::Entities::encode($alttext,'<>&"');
+	my $id=&Apache::loncommon::get_cgi_id();
+	$result="<img src='/cgi-bin/convertjme.pl?$id'";
+	if ($options =~ /border/) { $result.= ' border="1"'; }
+	$result.=' alt="'.$alttext.'" />';
+	&Apache::lonnet::appenv(
+            {'cgi.'.$id.'.JME'   => &escape($molecule),
+	     'cgi.'.$id.'.PNG' => 1,
+	     'cgi.'.$id.'.WIDTH' => $width});
+    } elsif ($target eq 'tex') {
+	my $texwidth=&Apache::lonxml::get_param('texwidth',$parstack,$safeeval,undef,1);
+	my $webwidth=&Apache::lonxml::get_param('width', $parstack, $safeeval);
+	my $webheight=&Apache::lonxml::get_param('height', $parstack, $safeeval);
+	if (!$webheight) { $webheight = $webwidth; }
+	if (!$texwidth) { $texwidth='90'; }
+	$result = "%DYNAMICIMAGE:$webwidth:$webheight:$texwidth\n";
+	my $molecule=&Apache::lonxml::get_param('molecule',$parstack,$safeeval);
+	my $options=&Apache::lonxml::get_param('options',$parstack,$safeeval);
+	my $filename = $env{'user.name'}.'_'.$env{'user.domain'}.
+	    '_'.time.'_'.$$.int(rand(1000)).'_organicstructure';
+	my $id=$filename;
+	&Apache::lonnet::appenv(
+		     {'cgi.'.$id.'.JME'   => &escape($molecule),
+		      'cgi.'.$id.'.PS' => 1,
+		      'cgi.'.$id.'.WIDTH' => $texwidth});
+	$id=&escape($id);
+	&Apache::lonxml::register_ssi("/cgi-bin/convertjme.pl?$id");
+	if ($options =~ /border/) { $result.= '\fbox{'; }
+	$result .= '\graphicspath{{'.LONCAPA::tempdir().
+	    '}}\includegraphics[width='.$texwidth.' mm]{'.$filename.'.eps}';
+	if ($options =~ /border/) { $result.= '} '; }
     } elsif ($target eq 'edit') {
 	$result .=&Apache::edit::tag_start($target,$token);
-	$result .=&Apache::edit::text_arg('Width:','width',$token,5);
-	$result .=&Apache::edit::text_arg('Height:','height',$token,5);
+	$result .=&Apache::edit::text_arg('Width (pixels):','width',$token,5);
+	$result .=&Apache::edit::text_arg('TeXwidth (mm):','texwidth',$token,5);
+	$result .='<span class="LC_nobreak">';
 	$result .=&Apache::edit::text_arg('Molecule:','molecule',$token,40);
 	my $molecule=&Apache::lonxml::get_param('molecule',$parstack,
 						$safeeval);
-	$result .=&seperate_jme_window(undef,
-		      &Apache::edit::html_element_name('molecule'),
-		      $molecule);
-	$result .=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
+	my $options=&Apache::lonxml::get_param('options',$parstack,
+					       $safeeval);
+	if ($options !~ /reaction/) {
+	    $options.= ',multipart,number';
+	}
+						   
+	$result .=&separate_jme_window(undef,
+				 &Apache::edit::html_element_name('molecule'),
+				       $molecule,$options);
+	$result.="</span><br />";
+	$result .=&Apache::edit::checked_arg('Options:','options',
+					     [ ['reaction','Is a reaction'],
+					       ['border','Draw a border'] ],
+					     $token);
+        $result .= '<br />'.&Apache::edit::text_arg('Alt text in JME img tag:','alt',$token,30).
+                   ' ('.&mt('student-viewable in HTML source').')';
+	$result .=&Apache::edit::end_row();
     } elsif ($target eq 'modified') {
 	my $constructtag=&Apache::edit::get_new_args($token,$parstack,
 						     $safeeval,'molecule',
-						     'width','height');
+						     'width','texwidth',
+						     'options','alt');
 	if ($constructtag) { $result = &Apache::edit::rebuild_tag($token); }
     }
     return $result;
 }
 
-sub end_chemstructure {
+sub end_organicstructure {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result;
     if ($target eq "edit") {
@@ -214,188 +637,66 @@ sub end_chemstructure {
     return $result;
 }
 
-sub reaction_javascript {
-    my $result=<<REACTIONJAVASCRIPT;
-    <SCRIPT language="JavaScript">
-
-var level;
-var reactants;
-var products;
-
-
-function parse_reaction(string) {
-  var reaction_array = string.split('->');
-  var i;
-  reactants = new Array(0);
-  products = new Array(0);
-
-  if (reaction_array.length > 0)
-    reactants = reaction_array[0].split(' +');
-  if (reaction_array.length > 1)
-    products = reaction_array[1].split(' +');
-}
-
-function to_capa(string) {
-  var reaction = "";
-  var i;
-
-  parse_reaction(string);
-
-  for (i = 0; i < reactants.length; i++)
-    reactants[i] = capa_component(reactants[i]);
-  for (i = 0; i < products.length; i++)
-    products[i] = capa_component(products[i]);
-
-  reactants.sort();
-  products.sort();
-
-  for (i = 0; i < reactants.length-1; i++) {
-    reaction += reactants[i];
-    reaction += " + ";
-  }
-  if (i < reactants.length)
-    reaction += reactants[i];
-  if (products.length > 0) {
-    reaction += " -> ";
-    for (i = 0; i < products.length-1; i++) {
-      reaction += products[i];
-      reaction += " + ";
-    }
-    if (i < products.length)
-      reaction += products[i];
-  }
-
-  return reaction;
-}
-
-function capa_component(string) {
-  var reactant = "";
-  var i = 0;
-  level = 0;
-
-  for (;string.substring(i,i+1) == ' ';i++)
-    ;
-  for (;isDigit(string.substring(i,i+1));i++)
-    reactant += string.substring(i,i+1);
-  for (;i < string.length;i++)
-    reactant +=  capa_char(string.substring(i,i+1));
-
-  return reactant;
-}
-
-function capa_char(chr) {
-  if (level == 0) { // baseline
-    if (chr == '^')
-      level = 1;
-    if (chr == ' ')
-      return "";
-    return chr;
-  }
-  if (level == 1) { // superscript
-    if (isDigit(chr))
-      return chr;
-    level = 0;
-    return chr;
-  }
-}
-
-function to_html(string) {
-  var reaction = "";
-  var i;
-
-  parse_reaction(string);
-  for (i = 0; i < reactants.length-1; i++) {
-    reaction += html_component(reactants[i]);
-    reaction += " + ";
-  }
-  if (i < reactants.length)
-    reaction += html_component(reactants[i]);
-
-  if (products.length > 0) {
-    reaction += " <font face=symbol>&reg;</font> ";
-    for (i = 0; i < products.length-1; i++) {
-      reaction += html_component(products[i]);
-      reaction += " + ";
-    }
-    if (i < products.length)
-      reaction += html_component(products[i]);
-  }
-
-  return reaction;
-}
-
-function html_component(string) {
-  var reactant = "";
-  var i = 0;
-  level = 0;
-
-  for (;string.substring(i,i+1) == ' ';i++)
-    ;
-  for (;isDigit(string.substring(i,i+1));i++)
-    reactant += string.substring(i,i+1);
-  for (;i < string.length;i++)
-    reactant +=  html_char(string.substring(i,i+1));
-
-  return reactant;
-}
-
-function html_char(chr) {
-  if (level == 0) { // baseline
-    if (isDigit(chr))
-      return chr.sub();
-    if (chr == '^') {
-      level = 1;
-      return "";
-    }
-    if (chr == '+') // baseline or superscript
-      return "?";
-    if (chr == ' ')
-      return "";
-    return chr;
-  }
-  if (level == 1) { // superscript
-    if (isDigit(chr))
-      return chr.sup();
-    if (chr == '+' || chr == '-') {
-      level = 0;
-      return chr.sup();
-    }
-    if (chr == ' ') {
-      level = 0;
-      return "";
-    }
-    level = 0;
-    return chr;
-  }
-}
-
-function isDigit(string) {
-  if (string >= '0' && string <='9')
-    return 1;
-  else
-    return 0;
-}
-
-function openHelpWindow() {
-  window.open("reaction_help.html","","scrollbars=yes,resizable=yes,width=550,height=600")
+sub edit_reaction_button {
+    my ($id,$field,$reaction)=@_;
+    my $id_es=&escape($id);
+    my $field_es=&escape($field);
+    my $reaction_es=&escape($reaction);
+    my $docopen=&Apache::lonhtmlcommon::javascript_docopen();
+    my $iconpath=$Apache::lonnet::perlvar{'lonIconsURL'};
+    my $display=&mt('Edit Answer');
+    my $start_page =
+        &Apache::loncommon::start_page('LON-CAPA Reaction Editor',undef,
+                                       {'frameset'    => 1,
+                                        'js_ready'    => 1,
+                                        'add_entries' => {
+                                            'rows'   => "30%,*",
+                                            'border' => "0",}},);
+    my $end_page =
+        &Apache::loncommon::end_page({'frameset' => 1,
+                                      'js_ready' => 1});
+    my $result=<<EDITREACTION;
+<script type="text/javascript">
+// <!--
+    function create_reaction_window_${id}_${field} () {
+        editor=window.open('','','width=500,height=270,scrollbars=no,resizable=yes');
+        editor.$docopen;
+        editor.document.writeln('$start_page <frame src="/adm/reactionresponse/reaction_viewer.html?inhibitmenu=yes" name="viewer" scrolling="no" />  <frame src="/adm/reactionresponse/reaction_editor.html?inhibitmenu=yes&reaction=$reaction_es&id=$id_es&field=$field_es" name="editor" scrolling="no" /> $end_page');
+        editor.document.close();
+    }
+// -->
+</script>
+<a href="javascript:create_reaction_window_${id}_${field}();void(0);"><img class="stift" src='$iconpath/stift.gif' alt='$display' title='$display' /></a>
+EDITREACTION
+    return $result;
 }
 
-function submitReaction() {
-  reaction = to_capa(document.form.text.value);
-  if (reaction == "") {
-    alert("Nothing to submit");
-  }
-  else {
-    name = "INPUT" + ((problem < 10) ? "0" : "") + problem;
-    i = 0;
-    while (parent.opener.document.CAPA.elements[i].name != name)
-      i++;
-    parent.opener.document.CAPA.elements[i].value = reaction;
-    parent.opener.document.CAPA.submit();
-  }
-}
-</SCRIPT>
-REACTIONJAVASCRIPT
+sub reaction_preview {
+    my ($field, $reaction) = @_;
+    
+    # NOTE: $reaction should be encoded if the document was sent as XHTML
+    $reaction =~ s/"//g;
+    my $result=<<JS_PREVIEW;
+<input type="button" value="Help" onclick = "window.open('/adm/reactionresponse/reaction_help.html','','scrollbars=yes,resizable=yes,width=550,height=600')" />
+<script type="text/javascript">
+    if (typeof reaction_preview_started === 'undefined') {
+        var script = document.createElement('script');
+        script.type = 'text/javascript';
+        script.src = '/adm/reactionresponse/reaction_preview.js';
+        document.body.appendChild(script);
+        reaction_preview_started = true;
+    }
+    window.addEventListener('load', function(e) {
+        var input = document.forms.lonhomework.$field;
+        input.readonly = '';
+        input.value = "$reaction";
+        if (!input.id)
+            input.id = "$field";
+        var preview = new LC.HW.ReactionPreview(input.id);
+        preview.start_preview();
+    }, false);
+</script>
+JS_PREVIEW
     return $result;
 }
 
@@ -403,11 +704,45 @@ sub start_reactionresponse {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result;
     my $id = &Apache::response::start_response($parstack,$safeeval);
-    if ($target eq 'web') {
-	$result.=&reaction_javascript();
-#	$result.='<iframe name="REACTION_'.$id.'" width="200" height="100" src="/adm/jme/reaction_viewer.html"></iframe>';
-	$result.='<input type="button" value="Check" onClick = "javascript:newWindow=open(\'\',\'new_W\',\'width=500,height=200,scrollbars=1\');newWindow.document.open(\'text/html\',\'replace\');newWindow.document.writeln(\'<center><br />\'+to_html(document.lonhomework.HWVAL_'.$id.'.value)+\'</center><input type="button" value="  Close  " onClick = "parent.window.close()" />\');newWindow.document.close()" />'
+    if ($target eq 'meta') {
+	$result=&Apache::response::meta_package_write('reactionresponse');
+    } elsif ($target eq 'web') {
+	my $partid = $Apache::inputtags::part;
+	my $id = $Apache::inputtags::response['-1'];
+	if (  &Apache::response::show_answer() ) {
+	    my $ans=&Apache::lonxml::get_param('answer',$parstack,$safeeval);
+	    if (!$Apache::lonxml::default_homework_loaded) {
+		&Apache::lonxml::default_homework_load($safeeval);
+	    }
+	    @Apache::scripttag::parser_env = @_;
+	    $Apache::inputtags::answertxt{$id}=[&Apache::run::run("return &chemparse(q\0$ans\0);",$safeeval)];
+	}
     } elsif ($target eq "edit") {
+	$result .=&Apache::edit::tag_start($target,$token);
+	my $answer=&Apache::lonxml::get_param('answer',$parstack,
+						$safeeval);
+	$result .='<span class="LC_nobreak">'.
+	    &Apache::edit::text_arg('Answer:','answer',$token,40);
+        my $inline_chem = &use_inline_chem();
+        if ($inline_chem) {
+	    $result .= &reaction_preview(&Apache::edit::html_element_name('answer'), $answer).'</span>';
+        } else {
+            $result .=&edit_reaction_button($id,&Apache::edit::html_element_name('answer'),$answer).'</span>';
+        }
+	my $initial=&Apache::lonxml::get_param('initial',$parstack,$safeeval);
+	$result.='<span class="LC_nobreak">'.
+	    &Apache::edit::text_arg('Initial Reaction:','initial',$token,40);
+        if ($inline_chem) { 
+            $result .= &reaction_preview(&Apache::edit::html_element_name('initial'), $initial).'</span>';
+        } else {
+            $result .=&edit_reaction_button($id,&Apache::edit::html_element_name('initial'),$initial).'</span>';
+        }
+	$result .=&Apache::edit::end_row().&Apache::edit::start_spanning_row();
+    }  elsif ($target eq 'modified') {
+	my $constructtag=&Apache::edit::get_new_args($token,$parstack,
+						     $safeeval,'answer',
+						     'initial');
+	if ($constructtag) { $result = &Apache::edit::rebuild_tag($token); }
     }
     return $result;
 }
@@ -415,12 +750,144 @@ sub start_reactionresponse {
 sub end_reactionresponse {
     my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style)=@_;
     my $result;
-    if ($target eq "edit") {
+
+    my $partid = $Apache::inputtags::part;
+    my $id = $Apache::inputtags::response['-1'];
+
+    if ($target eq 'grade' 
+	&& &Apache::response::submitted()
+	&& $Apache::lonhomework::type eq 'exam') {
+
+	&Apache::response::scored_response($partid,$id);
+
+    } elsif ($target eq 'grade' 
+	&& &Apache::response::submitted()
+	&& $Apache::lonhomework::type ne 'exam') {
+
+	&Apache::response::setup_params($$tagstack[-1],$safeeval);
+	my $response = &Apache::response::getresponse();
+	if ( $response =~ /[^\s]/) {
+	    my (@answers)=&Apache::lonxml::get_param_var('answer',$parstack,$safeeval);
+	    my %previous = &Apache::response::check_for_previous($response,$partid,$id);
+	    $Apache::lonhomework::results{"resource.$partid.$id.submission"}=$response;
+	    my $ad;
+	    foreach my $answer (@answers) {
+		&Apache::lonxml::debug("submitted a $response for $answer<br \>\n");
+		if (&chem_standard_order($response) eq 
+		    &chem_standard_order($answer)) {
+		    $ad='EXACT_ANS';
+		} else {
+		    $ad='INCORRECT';
+		}
+	    }
+            if ($ad) {
+                if ($Apache::lonhomework::type eq 'survey') {
+		    $ad='SUBMITTED';
+	        } elsif ($ad && $Apache::lonhomework::type eq 'surveycred') {
+                    $ad='SUBMITTED_CREDIT';
+                } elsif ($ad && $Apache::lonhomework::type eq 'anonsurvey') {
+                    $ad='ANONYMOUS';
+                } elsif ($ad && $Apache::lonhomework::type eq 'anonsurveycred') {
+                    $ad='ANONYMOUS_CREDIT';
+                }
+            }
+	    &Apache::response::handle_previous(\%previous,$ad);
+	    $Apache::lonhomework::results{"resource.$partid.$id.awarddetail"}=$ad;
+	}
+    }  elsif ($target eq "edit") {
 	$result.= &Apache::edit::tag_end($target,$token,'');
+    } elsif ($target eq 'answer') {
+	my (@answers)=&Apache::lonxml::get_param_var('answer',$parstack,
+						     $safeeval);
+	$result.=&Apache::response::answer_header('reactionresponse');
+	foreach my $answer (@answers) {
+	    $result.=&Apache::response::answer_part('reactionresponse',
+						    $answer);
+	}
+	$result.=&Apache::response::answer_footer('reactionresponse');
     }
-    &Apache::response::end_response;
+    if ($target eq 'web') {
+	&Apache::response::setup_prior_tries_hash(\&format_prior_response_reaction);
+    }
+
+    if ($target eq 'grade' || $target eq 'web' || $target eq 'answer' || 
+	$target eq 'tex' || $target eq 'analyze') {
+	my $repetition = &Apache::response::repetition();
+        &Apache::lonxml::increment_counter($repetition,"$partid.$id");
+        if ($target eq 'analyze') {
+            $Apache::lonhomework::analyze{"$partid.$id.type"} = 'reactionresponse';
+            push (@{ $Apache::lonhomework::analyze{"parts"} },"$partid.$id");
+            &Apache::lonhomework::set_bubble_lines();
+        }
+    }
+    my $status=$Apache::inputtags::status['-1'];
+    if  (($target eq 'web') && ($Apache::lonhomework::type ne 'exam') && ($status eq 'CAN_ANSWER')) {
+        my $reaction=$Apache::lonhomework::history{"resource.$partid.$id.submission"};
+        if ($reaction eq '') {  $reaction=&Apache::lonxml::get_param('initial',$parstack,$safeeval); }
+        if (&use_inline_chem()) {
+            $result .= &reaction_preview("HWVAL_$id", $reaction);
+        } else {
+            $result.=&edit_reaction_button($id,"HWVAL_$id",$reaction);
+        }
+    }
+    &Apache::response::end_response();
+    return $result;
+}
+
+sub use_inline_chem {
+    my $inline_chem = 1;
+    if (($env{'request.course.id'}) && ($env{'request.state'} ne 'construct')) {
+        if (exists($env{'course.'.$env{'request.course.id'}.'.inline_chem'})) {
+            if ($env{'course.'.$env{'request.course.id'}.'.inline_chem'} eq '0') {
+                $inline_chem = 0;
+            }
+        } else {
+            my %domdefs = &Apache::lonnet::get_domain_defaults($env{'course.'.$env{'request.course.id'}.'.domain'});
+            if ($domdefs{'inline_chem'} eq '0') {
+                $inline_chem = 0;
+            }
+        }
+    } else {
+        my %domdefs = &Apache::lonnet::get_domain_defaults($env{'course.'.$env{'request.course.id'}.'.domain'});
+        if ($domdefs{'inline_chem'} eq '0') {
+            $inline_chem = 0;
+        }
+    }
+    return $inline_chem;
+}
+
+sub format_prior_response_reaction {
+    my ($mode,$answer) =@_;
+    return '<span class="LC_prior_reaction">'.
+	    &HTML::Entities::encode($answer,'"<>&').'</span>';
+}
+
+sub start_chem {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
+    my $result = '';
+    my $inside = &Apache::lonxml::get_all_text_unbalanced("/chem",$parser);
+    if ($target eq 'tex' || $target eq 'web') {
+	$inside=&Apache::run::evaluate($inside,$safeeval,$$parstack[-1]);
+	if (!$Apache::lonxml::default_homework_loaded) {
+	    &Apache::lonxml::default_homework_load($safeeval);
+	}
+	@Apache::scripttag::parser_env = @_;
+	$result=&Apache::run::run("return &chemparse(q\0$inside\0);",$safeeval);
+    }    
     return $result;
 }
 
+sub end_chem {
+    my ($target,$token,$tagstack,$parstack,$parser,$safeeval,$style) = @_;
+    my $result = '';
+    return $result;
+}
+
+my $uniq=0;
+sub get_uniq_name {
+    $uniq++;
+    return 'uniquename'.$uniq;
+}
+
 1;
 __END__