--- loncom/html/res/adm/pages/reactionresponse/reaction_editor.html	2004/07/13 15:36:25	1.8
+++ loncom/html/res/adm/pages/reactionresponse/reaction_editor.html	2021/12/24 15:28:10	1.18
@@ -1,7 +1,7 @@
 <!-- Chemical reaction editor developed by Guy Ashkenazi, guy@fh.huji.ac.il-->
 
 <!--
- $Id: reaction_editor.html,v 1.8 2004/07/13 15:36:25 albertel Exp $
+ $Id: reaction_editor.html,v 1.18 2021/12/24 15:28:10 raeburn Exp $
 
  Copyright Michigan State University Board of Trustees
 
@@ -28,22 +28,14 @@
 
 <html>
 <head>
-<script type="text/javascript">
-var rightarrow;
+<script type="text/javascript" language="Javascript">
+var rightarrow = '&rarr;';
 var id;
 var reaction;
 var field
 </script>
 <!-- parsed by LON-CAPA to get the correct symbol for the arrow -->
-<display>
-return '<script type="text/javascript">
-          var rightarrow=\''.&xmlparse('<m>$\rightarrow$</m>').'\';
-	  var reaction=\''.&EXT('query.reaction').'\';
-	  var field=\''.&EXT('query.field').'\';
-	  var id=\''.&EXT('query.id').'\';
-        </script>';
-</display>
-<script language="JavaScript">
+<script type="text/javascript" language="Javascript">
 
 var level;
 var reactants;
@@ -135,8 +127,7 @@ function to_html(string) {
     reaction += html_component(reactants[i]);
     reaction += " + ";
   }
-  if (i < reactants.length)
-    reaction += html_component(reactants[i]);
+  reaction += html_component(reactants[i]);
 
   if (products.length > 0) {
     reaction += " "+rightarrow+" ";
@@ -144,8 +135,7 @@ function to_html(string) {
       reaction += html_component(products[i]);
       reaction += " + ";
     }
-    if (i < products.length)
-      reaction += html_component(products[i]);
+    reaction += html_component(products[i]);
   }
 
   return reaction;
@@ -154,12 +144,12 @@ function to_html(string) {
 function html_component(string) {
   var reactant = "";
   var i = 0;
-  level = 0;
+  level = -1;
 
-  for (;string.substring(i,i+1) == ' ';i++)
-    ;
-  for (;isDigit(string.substring(i,i+1));i++)
-    reactant += string.substring(i,i+1);
+  var hydrate = string.split('.');
+  if (hydrate.length > 1) 
+    return html_component(hydrate[0]) + "&middot;" + html_component(hydrate[1]);
+      
   for (;i < string.length;i++)
     reactant +=  html_char(string.substring(i,i+1));
 
@@ -167,6 +157,14 @@ function html_component(string) {
 }
 
 function html_char(chr) {
+  if (level == -1) { // stoichiometric coefficient
+    if (isDigit(chr) || chr == '/')
+      return chr;
+    if (chr == ' ')
+      return "";
+    else
+      level = 0;
+  }
   if (level == 0) { // baseline
     if (isDigit(chr))
       return chr.sub();
@@ -174,19 +172,25 @@ function html_char(chr) {
       level = 1;
       return "";
     }
-    if (chr == '+') // baseline or superscript
+    if (chr == '+') // baseline or superscript?
       return "?";
     if (chr == ' ')
       return "";
+    if (chr == '(' || chr == '|') // coefficient
+      level = -1;
     return chr;
   }
   if (level == 1) { // superscript
     if (isDigit(chr))
       return chr.sup();
-    if (chr == '+' || chr == '-') {
+    if (chr == '+') {
       level = 0;
       return chr.sup();
     }
+    if (chr == '-') {
+      level = 0;
+      return "<sup>&minus;</sup>";
+    } 
     if (chr == ' ') {
       level = 0;
       return "";
@@ -224,29 +228,27 @@ function submitReaction() {
 }
 
 function setup() {
+  var query = window.location.search.substring(1);
+  var vars = query.split("&");
+  for (var i=0;i<vars.length;i++) {
+      var pair = vars[i].split("=");
+      if (pair[0] == 'reaction' ) {
+          reaction = decodeURIComponent(pair[1]);
+      }
+      if (pair[0] == 'field') {
+          field = decodeURIComponent(pair[1]);
+      }
+      if (pair[0] == 'id') {
+          id = decodeURIComponent(pair[1]);
+      }
+  }
   document.form.text.value=reaction;
-  parent.viewer.document.writeln('<center><br>'+to_html(document.form.text.value)+'</center>');
+  parent.viewer.document.writeln('<center><br />'+to_html(document.form.text.value)+'</center>');
   parent.viewer.document.close();
   document.form.submit.value='Insert Answer';
   parent.document.title='LON-CAPA - Reaction Editor';
 }
 
-function getCookie(document,name) {
-  var dc = document.cookie;
-  var prefix = name + "=";
-  var begin = dc.indexOf("; " + prefix);
-  if (begin == -1) {
-    begin = dc.indexOf(prefix);
-    if (begin != 0) return null;
-  } else
-    begin += 2;
-  var end = document.cookie.indexOf(";", begin);
-  if (end == -1)
-    end = dc.length;
-  return unescape(dc.substring(begin + prefix.length, end));
-}
-
-
 </script>
 </head>
 
@@ -254,14 +256,14 @@ function getCookie(document,name) {
 <center>
 <hr />
 <form name="form">
-<input type="text" size=50 name="text" />
-<input type="button" value="Check" onClick = "parent.viewer.document.writeln('<center><br>'+to_html(document.form.text.value)+'</center>');parent.viewer.document.close()" /><br />
+<input type="text" size="50" name="text" />
+<input type="button" value="Check" onclick = "parent.viewer.document.writeln('<center><br />'+to_html(document.form.text.value)+'</center>');parent.viewer.document.close()" /><br />
 <br />
-<input type="button" name="submit" value="Insert reaction for part #?" onClick = "submitReaction();" />
+<input type="button" name="submit" value="Insert reaction for part #?" onclick = "submitReaction();" />
 <br />
-<input type="button" value="  Close  " onClick = "parent.window.close()" />
+<input type="button" value="  Close  " onclick = "parent.window.close()" />
 &nbsp;&nbsp;
-<input type="button" value="  Help  " onClick = "openHelpWindow()" />
+<input type="button" value="  Help  " onclick = "openHelpWindow()" />
 </form>
 </center>
 </body>
