ENH: g1.formhandler supports multiple sort #75

src/formhandler.template.html

@@ -71,16 +71,21 @@ Each template receives these variables:
         col_defaults(colinfo, data)
         var menu_item = false
         var col_id = idcount++
+        var qsort = parse('?')
+        var isSorted = _.includes(args['_sort'], colinfo.name) ? {op: '', cls: 'table-primary'} : _.includes(args['_sort'], '-' + colinfo.name) ? {op: '-', cls: 'table-danger'} : {}
       %>
-      <th class="<%- args['_sort'] == colinfo.name ? 'table-primary' : args['_sort'] == '-' + colinfo.name ? 'table-danger' : '' %>" data-col="<%- colinfo.name %>">
+      <th class="<%- isSorted.cls %>" data-col="<%- colinfo.name %>">
         <div class="dropdown">
           <a href="#" class="dropdown-toggle text-nowrap" id="fh-dd-<%- col_id %>" data-toggle="dropdown" aria-haspopup="true" aria-expanded="false">
             <%- colinfo.title || colinfo.name %>
           </a>
           <div class="dropdown-menu" aria-labelledby="fh-dd-<%- col_id %>">
             <% _.each(colinfo.sort, function(title, op) { menu_item = true
-              var active = args['_sort'] == op + colinfo.name %>
-              <a class="dropdown-item urlfilter <%- active ? 'active': '' %>" href="?_sort=<%- active ? '' : op + colinfo.name %>">
+              qsort = qsort.update({_sort: args['_sort'] || []})
+              if (!_.isEmpty(isSorted))
+                qsort = qsort.update({_sort: [colinfo.name, '-' + colinfo.name]}, 'del')
+              var active = _.includes(args['_sort'], op + colinfo.name) %>
+              <a class="dropdown-item urlfilter <%- active ? 'active': '' %>" href="<%- qsort.update({_sort: [op + colinfo.name]}, active ? 'del': 'add').toString() %>">
                 <%- title %>
               </a>
             <% }) %>